MAX15500GTJ+T - Maxim Integrated - Datasheet.Technology

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

EVALUATION KIT AVAILABLE

General Description

The MAX15500/MAX15501 analog output conditioners

provide a programmable current up to Q24mA, or a volt-

age up to Q12V proportional to a control voltage signal.

The control voltage is typically supplied by an external

DAC with an output voltage range of 0 to 4.096V for the

MAX15500 and 0 to 2.5V for the MAX15501. The output

current and voltage are selectable as either unipolar or

bipolar. In the unipolar configuration, a control voltage

of 5% full-scale (FS) produces a nominal output of 0A or

0V to achieve underrange capability. A control voltage

of 100%FS produces one of two programmable levels

(105%FS or 120%FS) to achieve overrange capability.

The outputs of the MAX15500/MAX15501 are protected

against overcurrent conditions and a short to ground or

supply voltages up to Q35V. The devices also monitor for

overtemperature and supply brownout conditions. The

supply brownout threshold is programmable.

The MAX15500/MAX15501 are programmed through an

SPIK interface capable of daisy-chained operation. The

MAX15500/MAX15501 provide extensive error reporting

through the SPI interface and an additional open-drain

interrupt output. The devices include an analog output to

monitor load conditions.

The MAX15500/MAX15501 operate over the -40NC to

+105NC temperature range. The devices are available in

a 32-pin, 5mm x 5mm TQFN package.

Applications

Programmable Logic Controllers (PLCs)

Distributed I/Os

Embedded Systems

Industrial Control and Automation

Features

S Supply Voltage Up to Q32.5V

S Output Protected Up to Q35V

S Programmable Output (Plus Overrange)

±10V

0 to 10V

0 to 5V

±20mA

0 to 20mA

4 to 20mA

S Current Output Drives 0 to 1kI

S Voltage Output Drives Loads Down to 1kI

S HART Compliant

S 2ppm Gain Error Drift Over Temperature

S SPI Interface, with Daisy-Chain Capability

S Supports +4.096V (MAX15500) or +2.5V

(MAX15501) Full-Scale Input Signals

S Extensive Error Reporting

Short-Circuit and Overcurrent Protection

Open-Circuit Detection

Brownout Detection

Overtemperature Protection

S Fast, 40µs Settling Time

19-4602; Rev 2; 10/15

Ordering Information

Note: All devices are specified over the -40NC to +105NC operating

temperature range.

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

SPI is a trademark of Motorola, Inc.

SPI

INTERFACE

DIN

SCLK

CS1

DOUT

READY

ERROR

MON

REFIN

AIN

DVDD

AVSS

AVDD

FSMODE FSSEL AGND DGND

OUT

SENSERN

COMP

CS2

OUTDIS

AVSSO

AVDDO

ERROR

HANDLING

BIDIRECTIONAL

CURRENT

DRIVER

BIDIRECTIONAL

VOLTAGE

DRIVER

ERROR

HANDLING

OVER-

CURRENT

PROTECTION

SENSERP

SENSEVP

SENSEVN

MAX15500

MAX15501

Pin Configuration

MAX15500

MAX15501

TQFN

TOP VIEW

DIN

READY

ERROR

DVDD

DGND

SCLK

SENSEVN

SENSERP

AVDDO

N.C.

OUT

COMP

AVSS

4567

2324 22 20 19 18

MON

CS1

AIN

REFIN

AGND

FSMODE

DOUT SENSERN

31 10

CS2 FSSEL

32 9

N.C. OUTDIS

EP*

*EXPOSED PAD.

AGND

26 15 AGND

AVDD

25 16 N.C.

N.C. AVSSO

SENSEVP

Simplified Block Diagram

PART PIN-PACKAGE REFERENCE

MAX15500GTJ+ 32 TQFN-EP* +4.096V

MAX15500KGTJ+ 32 TQFN-EP* +4.096V

MAX15501GTJ+ 32 TQFN-EP* +2.5V

MAX15501KGTJ+ 32 TQFN-EP* +2.5V

2 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional

operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute

maximum rating conditions for extended periods may affect device reliability.

AVDD to AGND .....................................................-0.3V to +35V

AVSS to AGND ......................................................-35V to +0.3V

AVDD to AVSS ............................................................. 0 to +70V

AVDD to AVDDO ........................................................... 0 to +4V

AVSS to AVSSO ............................................................ -4V to 0V

DGND to AGND ...................................................-0.3V to +0.3V

AVDD to DVDD .........................................................-6V to +35V

DVDD to DGND .................................................... -0.3V to +6.0V

CS1, CS2, SCLK, DIN, DOUT, READY, ERROR, FSMODE,

MON, OUTDIS, FSSEL to DGND ......................-0.3V to +6.0V

AIN, REFIN to AGND ............................................-0.3V to +6.0V

SENSEVP, SENSEVN, SENSERP,

SENSERN to AGND the higher of -35V and (VAVSS - 0.3V) to

the lower of (VAVDD + 0.3V) and +35V

OUT, COMP to AGND .. the higher of -35V and (VAVSS - 0.3V) to

the lower of (VAVDD + 0.3V) and +35V

Maximum Current on Pin ............................................... ±100mA

Continuous Power Dissipation (derate 34.5mW/NC above +70NC)

32-Pin TQFN (TA = +70NC, multilayer board) ......... 2758.6mW

Operating Temperature Range ........................ -40NC to +105NC

Storage Temperature Range ............................ -65NC to +150NC

Lead Temperature (soldering, 10s) ................................+300NC

Soldering Temperature (reflow) ......................................+260NC

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for

the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

POWER SUPPLY (Note 1)

Analog Positive Supply Voltage VAVDD 5% overrange (FSMODE = DVDD) 15 24 32.5 V

20% overrange (FSMODE = DGND) 18.5 24 32.5

Analog Negative Supply

Voltage VAVSS 5% overrange (FSMODE = DVDD) -32.5 -24 -15 V

20% overrange (FSMODE = DGND) -32.5 -24 -18.5

AVDD to AVDDO Voltage

Difference VAVDDO (Note 1) 2.5 V

AVSS to AVSSO Voltage

Difference VAVSSO (Note 1) 2.5 V

Digital Supply Voltage VDVDD 2.7 5.25 V

Analog Positive Supply Current IAP IAP = IAVDD + IAVDDO, ILOAD = 0A 5 7 mA

Analog Negative Supply Current IAN IAN = IAVSS + IAVSSO, ILOAD = 0A -7 -4.5 mA

Digital Supply Current IDVDD VDVDD = 5V 0.1 0.4 mA

Analog Positive Standby Current ISTBYP ISTBYP = IAVDD + IAVDDO, OUTDIS =

DGND or software standby mode 1 mA

Analog Negative Standby Current ISTBYN ISTBYN = IAVSS + IAVSSO, OUTDIS =

DGND or software standby mode -0.5 mA

ANALOG INPUT (AIN, REFIN)

Input Impedance RIN 10 kI

Input Capacitance CIN 10 pF

Analog Input Full Scale VAIN FSSEL = DVDD, MAX15500 4.0 4.096 4.2 V

FSSEL = DGND, MAX15501 2.4 2.5 2.6

REFIN Full-Scale Input VREFIN FSSEL = DVDD, MAX15500 4.0 4.096 4.2 V

FSSEL = DGND, MAX15501 2.4 2.5 2.6

3Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for

the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CURRENT OUTPUT (Note 2)

Maximum Load Resistance RLOAD VAVDD = +24V, VAVSS = -24V 750 I

VAVDD = +32.5V, VAVSS = -32.5V 1000

Maximum Load Inductance LLOAD CCOMP = 100nF (Note 3) 15 mH

Maximum Load Capacitance CLOAD CCOMP = 4.7nF 100 FF

Maximum Settling Time

Full-scale step

from 0 to 20mA or

-20mA to + 20mA,

RLOAD = 750I

To 0.1% accuracy,

LLOAD = 20FH,

CCOMP = 0nF

To 0.1% accuracy,

LLOAD = 1mH,

CCOMP = 0.15nF

500

To 0.1% accuracy,

LLOAD = 10mH,

CCOMP = 0.15nF

500

To 0.01% accuracy,

LLOAD = 20FH,

CCOMP = 0nF

To 0.01% accuracy,

LLOAD = 10mH,

CCOMP = 0.15nF

600

1% full-scale step,

RLOAD = 750I

To 0.1% accuracy,

LLOAD = 20FH,

CCOMP = 0nF

To 0.1% accuracy,

LLOAD = 1mH,

CCOMP = 0.15nF

100

To 0.1% accuracy,

LLOAD = 10mH,

CCOMP = 0.15nF

100

To 0.01% accuracy,

LLOAD = 20FH,

CCOMP = 0nF

To 0.01% accuracy,

LLOAD = 10mH,

CCOMP = 0.15nF

200

Full-Scale Output Current IOUT VFSMODE = VDVDD Q21 mA

VFSMODE = VDGND Q24

4 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for

the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Offset Error VAIN = 5% of VREFIN (unipolar mode),

VAIN = 50% of VREFIN (bipolar mode) Q0.1 Q0.5 %FS

Offset-Error Drift Q5ppm/NC

Gain Error GE

0.01% precision

RSENSE, tested

according to the

ideal transfer

functions shown in

Table 8

MAX15500 Q0.1 Q0.51

%FS

MAX15501 Q0.1 Q0.5

Gain-Error Drift No RSENSE drift Q2ppm/NC

Integral Nonlinearity Error INL 0.05 %FS

Output Conductance

(dIOUT/dVOUT), IOUT = 24mA, RLOAD =

750I to 0I, FSMODE = DGND, unipolar

mode

1.0 FA/V

Power-Supply Rejection Ratio PSRR

At DC, VAVDD = +24V to +32.5V, VAVSS

= -24V to -32.5V, VAIN = VREFIN, unipolar

mode, FSMODE = DVDD

1.6 FA/V

Overcurrent Limit RSENSE shorted 25 30 40 mA

Output Current Noise 0.1Hz to 10Hz 20 nARMS

At 1kHz 2.6 nA/√Hz

Output Slew Rate 1.5 mA/Fs

Small-Signal Bandwidth 30 kHz

Maximum OUT Voltage to

AVDDO VAVDDO - VOUT 2.0 V

Minimum OUT Voltage to

AVSSO VOUT - VAVSSO 2.0 V

VOLTAGE OUTPUT (RLOAD = 1kI)

Minimum Resistive Load RLOAD 1kI

Maximum Capacitive Load CLOAD CCOMP = 4.7nF 100 FF

Maximum Settling Time (Full-

Scale Step)

To 0.1% accuracy, load = 1kI in parallel

with 1nF, CCOMP = 0nF 20

To 0.1% accuracy, load = 1kI in parallel

with 1FF, CCOMP = 4.7nF 1000

To 0.01% accuracy, load = 1kI in parallel

with 1nF, CCOMP = 0nF 30

To 0.01% accuracy, load = 1kI in parallel

with 1FF, CCOMP = 4.7nF 1300

5Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for

the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Maximum Settling Time

(1% Full-Scale Step)

To 0.1% accuracy, load = 1kI in parallel

with 1nF, CCOMP = 0nF 10

To 0.1% accuracy, load = 1kI in parallel

with 1FF, CCOMP = 4.7nF 300

To 0.01% accuracy, load = 1kI in parallel

with 1nF, CCOMP = 0nF 20

To 0.01% accuracy, load = 1kI in parallel

with 1FF, CCOMP = 4.7nF 600

Gain Error Tested according to the ideal transfer

functions shown in Table 9 Q0.1 Q0.5 %FS

Gain-Error Drift Q2ppm/NC

Full-Scale Output Voltage VOUT

FSMODE = DVDD

5V range 5.25

10V range 10.5

FSMODE = DGND

5V range 6

10V range 12

Offset Error VAIN = 5% of VREFIN (unipolar mode),

VAIN = 50% of VREFIN (bipolar mode) Q0.1 Q0.5 %FS

Offset-Error Drift Q2ppm/NC

Integral Nonlinearity Error INL 0.05 %FS

Power-Supply Rejection PSRR At DC, VAVDD = +18.5V to +32.5V, VAVSS

= -18.5V to -32.5V, VAIN = VREFIN 30 FV/V

Output-Voltage Noise 0.1Hz to 10Hz 16.3 FVRMS

1kHz 250 nV/√Hz

Output-Voltage Slew Rate 1.5 V/Fs

Short-Circuit Current 20 30 45 mA

Maximum OUT Voltage to

AVDDO VAVDDO - VOUT 2.0 V

Minimum OUT Voltage to

AVSSO VOUT - VAVSSO 2.0 V

6 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for

the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

OUTPUT MONITOR (MON)

Maximum Output Voltage

Current mode, see the Output Monitor

section for VMON equations 3

Voltage mode, see the Output Monitor

section for VMON equations 3

Output Resistance 35 kI

OVERTEMPERATURE DETECTION

Overtemperature Threshold +150 NC

Overtemperature Threshold

Hysteresis 10 NC

DIGITAL INPUTS (CS1, CS2, SCLK, DIN, OUTDIS, FSSEL, FSMODE)

Input High Voltage VIH 0.7 x

VDVDD V

Input Low Voltage VIL 0.3 x

VDVDD V

Input Hysteresis VIHYST 300 mV

Input Leakage Current IIN VINPUT = 0V or VDVDD Q0.1 Q1.0 FA

Input Capacitance CIN 10 pF

DIGITAL OUTPUT (DOUT, READY)

Output Low Voltage VOL ISINK = 4mA 0.4 V

Output High Voltage VOH ISOURCE = 4mA VDVDD -

0.5 V

Output Three-State Leakage IOZ DOUT only Q0.1 Q10 FA

Output Three-State Capacitance COZ DOUT only 15 pF

Output Short-Circuit Current IOSS VDVDD = 5.25V Q150 mA

DIGITAL INTERRUPT (ERROR)

Interrupt Active Voltage VINT ISINK = 5.0mA 0.4 V

Interrupt Inactive Leakage IINTZ Q0.1 Q1.0 FA

Interrupt Inactive Capacitance CINTZ 15 pF

Interrupt Short-Circuit Current IINTSS VDVDD = 2.7V 5 30 mA

7Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Note 1: Use diodes as shown in the Typical Operating Circuit/Functional Diagram to ensure a voltage difference of 2V to 3.5V

from AVDD to AVDDO and from AVSS to AVSSO.

Note 2: RLOAD = 750I. For the MAX15500, RSENSE = 48.7I for FSMODE = DVDD and RSENSE = 42.2I for FSMODE = DGND.

For the MAX15501, RSENSE = 47.3I for FSMODE = DVDD and RSENSE = 41.2I for FSMODE = DGND. See the Typical

Operating Circuit/Functional Diagram.

Note 3: Condition at which part is stable.

Note 4: The maximum clock speed for daisy-chain applications is 10MHz.

Note 5: tCSH is applied to CS_ falling to determine the 1st SCLK falling edge in a free-running SCLK application. It is also applied

to CS_ rising with respect to the 15th SCLK falling edge to determine the end of the frame.

Note 6: After the 14th SCLK falling edge, the MAX15500/MAX15501 outputs are high impedance and DOUT data is ignored.

ELECTRICAL CHARACTERISTICS (continued)

(VAVDD = +24V, VAVSS = -24V, VDVDD = 5.0V, CLOAD = 1nF, CCOMP = 0nF, VREFIN = 4.096V for the MAX15500, VREFIN = 2.5V for

the MAX15501. All specifications for TA = -40NC to +105NC. Typical values are at TA = +25NC, unless otherwise noted.)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

TIMING CHARACTERISTICS

Serial-Clock Frequency fSCLK (Note 4) 0 20 MHz

SCLK Pulse-Width High tCH 40% duty cycle 20 ns

SCLK Pulse-Width Low tCL 60% duty cycle 20 ns

CS_ Fall to SCLK Fall Setup Time tCSS To 1st SCLK falling edge 15 ns

SCLK Fall to CS_ Fall Hold Time tCSH (Note 5) 0 ns

DIN to SCLK Fall Setup Time tDS 15 ns

DIN to SCLK Fall Hold Time tDH 0 ns

SCLK Fall to DOUT Settle Time tDOT CLOAD = 20pF 30 ns

SCLK Fall to DOUT Hold Time tDOH CLOAD = 0pF 2 ns

SCLK Fall to DOUT Disable tDOZ 14th SCLK deassertion (Note 6) 30 ns

SCLK Fall to READY Fall tCR 16th SCLK assertion, CLOAD = 0pF or 20pF 2 30 ns

CS_ Fall to DOUT Enable tDOE Asynchronous assertion 1 35 ns

CS_ Rise to DOUT Disable tCSDOZ Asynchronous deassertion 35 ns

CS_ Rise to READY Rise tCSR Asynchronous deassertion, CLOAD = 20pF 35 ns

CS_ Pulse-Width High tCSW 15 ns

8 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Typical Operating Characteristics

(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output

mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)

SUPPLY CURRENT vs. TEMPERATURE

MAX15500 toc01

TEMPERATURE (NC)

SUPPLY CURRENT (mA)

958050 65-10 5 20 35-25

-8

-6

-4

-2

-40 105

IAVDD

IAVSS

NO LOAD

VOLTAGE-MODE OUTPUT SLEW

RATE vs. TEMPERATURE

MAX15500 toc02

TEMPERATURE (NC)

OUTPUT SLEW RATE (V/

9580655035205-10-25

0.5

1.0

1.5

2.0

2.5

3.0

-40 105

NO LOAD

CURRENT-MODE OUTPUT SLEW

RATE vs. TEMPERATURE

MAX15500 toc03

TEMPERATURE (NC)

OUTPUT SLEW RATE (mA/Fs)

9580655035205-10-25

0.5

1.0

1.5

2.0

2.5

3.0

-40 105

RLOAD = 750I

CLOAD = 1FF

VOLTAGE-MODE OUTPUT NOISE

vs. FREQUENCY

MAX15500 toc04

FREQUENCY (Hz)

OUTPUT NOISE (FV/ Hz)

1k100

100

200

300

400

500

600

700

800

900

1000

10 10k

VAIN = 0V

UNIPOLAR

VOLTAGE

MODE (0 to 5V)

CURRENT-MODE OUTPUT NOISE

vs. FREQUENCY

MAX15500 toc05

FREQUENCY (Hz)

OUTPUT NOISE (

V/ Hz)

1k100

100

200

300

400

500

600

700

800

900

1000

10 10k

VAIN = 200mV

UNIPOLAR

CURRENT MODE

(0 to 20mA)

MAX15500 toc06

2V/div

VOUT (AC-COUPLED)

1mV/div

400ns/div

DIGITAL FEEDTHROUGH

SCLK

SCLK = DIN

SCLK = 1MHz

CS_ = HIGH

VAIN = 0.5 x VREFIN

VOLTAGE-MODE PSRR

vs. SUPPLY VOLTAGE

MAX15500 toc07

SUPPLY VOLTAGE (V)

PSRR (FV/V)

302826

100

24 32

VAIN = 4.096V

9Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Typical Operating Characteristics (continued)

(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output

mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)

CURRENT-MODE PSRR vs.

SUPPLY VOLTAGE

MAX15500 toc08

SUPPLY VOLTAGE (V)

PSRR (FA/V)

313028 2926 2725

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

24 32

MAX15500 toc09

VOUT (AC-COUPLED)

20mV/div

40Fs/div

LOAD TRANSIENT (VOLTAGE MODE)

IOUT

10mA/div

OmA

MAX15500 toc10

IOUT

10mA/div

40Fs/div

0mA

LOAD TRANSIENT (CURRENT MODE)

VOUT

10V/div

FULL-SCALE OUTPUT VOLTAGE

vs. TEMPERATURE

MAX15500 toc11

TEMPERATURE (NC)

FULL-SCALE OUTPUT VOLTAGE (ppm/NC)

958050 65-10 5 20 35-25

-16

-12

-8

-4

-20

-40

VAIN = 4.096V

958050 65-10 5 20 35-25-40

OUTPUT CURRENT DRIFT

vs. TEMPERATURE

MAX15500 toc12

TEMPERATURE (NC)

OUTPUT CURRENT DRIFT (ppm/NC)

-6

-2

-10

VAIN = 4.096V

STANDBY SUPPLY CURRENT

vs. TEMPERATURE

MAX15500 toc13

TEMPERATURE (NC)

SUPPLY CURRENT (mA)

9580-25 -10 5 35 5020 65

-1.5

-1.0

-0.5

0.5

1.0

1.5

2.0

-2.0

-40

IAVDD

IAVSS

NO LOAD

10 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Typical Operating Characteristics (continued)

(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output

mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)

WAKEUP FROM STANDBY

(VOLTAGE MODE)

MAX15500 toc14

50Fs/div

5V/div

VOUT

2V/div

OUTDIS

FULL-SCALE INPUT

BIPOLAR VOLTAGE MODE

5% OVERRANGE

MAX15500 toc15

IOUT

10mA/div

40Fs/div

WAKEUP FROM STANDBY

(CURRENT MODE)

OUTDIS

2V/div

GAIN vs. FREQUENCY

(HART COMPLIANT)

MAX15500 toc16

FREQUENCY (Hz)

GAIN (dB)

10k1k100

-16

-12

-8

-4

-20

10 100k

UNIPOLAR

CURRENT MODE

BIPOLAR

CURRENT MODE

VAIN = 40mVP-P

MAX15500 toc17

IOUT

100FA/div

5Fs/div

SMALL-SIGNAL STEP RESPONSE

(CURRENT MODE)

VAIN

20mV/div

MAX15500 toc18

VOUT

(AC-COUPLED)

100mV/div

1Fs/div

SMALL-SIGNAL STEP RESPONSE

(VOLTAGE MODE)

VAIN

(AC-COUPLED)

50mV/div

OUTPUT SHORT-CIRCUIT CURRENT

vs. TEMPERATURE

MAX15500 toc19

TEMPERATURE (NC)

SHORT-CIRCUIT CURRENT (mA)

958050 65-10 5 20 35-25

30.5

31.0

31.5

32.0

32.5

33.0

33.5

34.0

34.5

35.0

30.0

-40

VAIN = 4.096V

VOLTAGE-MODE MON TRANSFER

CURVE vs. OUTPUT CURRENT

MAX15500 toc20

IOUT (mA)

MON (V)

10987654321

1.4

1.8

2.2

2.6

3.0

1.0

0 11

VAIN = 4.096V

NO LOAD ON MON

CURRENT-MODE MON TRANSFER

CURVE vs. OUTPUT VOLTAGE

MAX15500 toc21

VOUT (V)

MON (V)

1284

1.2

1.4

1.6

1.8

2.0

2.2

2.4

2.6

2.8

3.0

1.0

0 16

VAIN = 4.096V

NO LOAD ON MON

VOLTAGE-MODE MAXIMUM OUT TO

AVDDO VOLTAGE vs. TEMPERATURE

MAX15500 toc22

TEMPERATURE (NC)

MAXIMUM INTERNAL VOLTAGE DROP (V)

958050 65-10 5 20 35-25

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-40

VAIN = 4.096V

11Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Typical Operating Characteristics (continued)

(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output

mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)

CURRENT-MODE OUTPUT

CONDUCTANCE vs. OUTPUT VOLTAGE

MAX15500 toc23

OUTPUT VOLTAGE (V)

OUTPUT CONDUCTANCE (FA/V)

14128 104 62

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

0 16

MAX15500 toc24

VOUT

5V/div

100Fs/div

LARGE-SIGNAL SETTLING TIME

(VOLTAGE MODE, RISING EDGE)

VAIN

5V/div

RL = 1kI

CL = 1nF, CCOMP = 0nF

CL = 470nF, CCOMP = 4.7nF

CL = 47nF, CCOMP = 0nF

MAX15500 toc25

VOUT

5V/div

100Fs/div

LARGE-SIGNAL SETTLING TIME

(VOLTAGE MODE, FALLING EDGE)

VAIN

5V/div

RL = 1kI

CL = 1nF, CCOMP = 0nF

CL = 470nF, CCOMP = 4.7nF

CL = 47nF, CCOMP = 0nF

MAX15500 toc26

VOUT

10ms/div

LARGE-SIGNAL SETTLING TIME

(VOLTAGE MODE, RISING EDGE)

VAIN

5V/div

RL = 1kI

CL = 1FF, CCOMP = 4.7nF

CL = 10FF,

CCOMP = 4.7nF

CL = 100FF,

CCOMP = 4.7nF

MAX15500 toc27

VOUT

5V/div

10ms/div

LARGE-SIGNAL SETTLING TIME

(VOLTAGE MODE, RISING EDGE)

VAIN

5V/div

RL = 1kI

CL = 10FF,

CCOMP = 4.7nF

CL = 100FF,

CCOMP = 4.7nF

CL = 1FF, CCOMP = 4.7nF

MAX15500 toc28

IOUT

4mA/div

200Fs/div

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, RISING EDGE)

VAIN

5V/div

RL = 750I

LL = 220FH, CCOMP = 0nF

LL = 1mH, CCOMP = 1nF

LL = 22FH, CCOMP = 0nF

MAX15500 toc29

IOUT

4mA/div

200Fs/div

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, FALLING EDGE)

VAIN

5V/div

RL = 750I

LL = 220FH, CCOMP = 0nF

LL = 1mH, CCOMP = 1nF

LL = 22FH, CCOMP = 0nF

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, RISING EDGE)

MAX15500 toc30

IOUT

4mA/div

20Fs/div

VAIN

5V/div

RL = 20I

LL = 220FH,

CCOMP = 0.47nF

LL = 1mH, CCOMP = 1nF

LL = 22FH, CCOMP = 0.15nF

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, FALLING EDGE)

MAX15500 toc31

IOUT

4mA/div

20Fs/div

VAIN

RL = 20I

LL = 220FH,

CCOMP = 0.47nF

LL = 1mH, CCOMP = 1nF

LL = 22FH, CCOMP = 0.15nF

12 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Typical Operating Characteristics (continued)

(VAVDD = +24V, VDVDD = +5V, VAVSS = -24V, CLOAD = 1nF, 5% overrange mode, unipolar current output or bipolar voltage-output

mode, VREFIN = +4.096V, TA = +25NC, unless otherwise specified.)

CURRENT-MODE INL

MAX15500 toc36

VAIN (V)

INL (%FS)

3.63.00.6 1.2 1.8 2.4

-0.03

-0.02

-0.01

0.01

0.02

0.03

0.04

-0.04

0 4.2

VOLTAGE-MODE INL

MAX15500 toc37

VAIN (V)

INL (%FS)

3.63.00.6 1.2 1.8 2.4

-0.03

-0.02

-0.01

0.01

0.02

0.03

0.04

-0.04

0 4.2

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, RISING EDGE)

MAX15500 toc32

IOUT

4mA/div

100ms/div

VAIN

5V/div

RL = 750I

LL = 80mH, CCOMP = 470nF

LL = 50mH, CCOMP = 100nF

LL = 10mH, CCOMP = 10nF

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, FALLING EDGE)

MAX15500 toc33

IOUT

4mA/div

100ms/div

VAIN

5V/div

RL = 750I

LL = 50mH, CCOMP = 100nF

LL = 80mH, CCOMP = 470nF

LL = 10mH, CCOMP = 10nF

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, RISING EDGE)

MAX15500 toc34

IOUT

4mA/div

10ms/div

VAIN

5V/div

RL = 20I

LL = 80mH,

CCOMP = 470nF

LL = 50mH, CCOMP = 100nF

LL = 10mH, CCOMP = 10nF

LARGE-SIGNAL SETTLING TIME

(CURRENT MODE, FALLING EDGE)

MAX15500 toc35

IOUT

4mA/div

10ms/div

VAIN

20V/div

LL = 80mH, CCOMP = 470nF

LL = 50mH, CCOMP = 100nF

LL = 10mH, CCOMP = 10nF

RL = 20I

VOLTAGE-MODE

SHORT-CIRCUIT DETECTION

MAX15500 toc38

100ms/div

2V/div

50mA/div

ERROR

IOUT

0mA

CURRENT-MODE

OPEN-CIRCUIT DETECTION

MAX15500 toc39

100ms/div

2V/div

50mA/div

ERROR

IOUT

0mA

13Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Pin Description

PIN NAME FUNCTION

1 SCLK SPI Clock Input. Activate SCLK only when CS_ is low to minimize noise coupling.

2 DIN SPI Data Input. Data is clocked into the serial interface on the falling edge of SCLK.

3 DOUT SPI Data Output. Data transitions at DOUT on the falling edge of SCLK. DOUT is high impedance

when either CS1 or CS2 is high.

4READY

Active-Low Device Ready Output. READY is an active-low output that goes low when the device

successfully completes processing an SPI data frame. READY returns high at the next rising edge

of CS_. In daisy-chain applications, the READY output typically drives the CS_ input of the next

device in the chain or a GPIO of a microcontroller.

5ERROR

Active-Low Flag Output. ERROR is an open-drain output that pulls low when output short circuit,

output open circuit, overtemperature, or brownout conditions occur. ERROR typically drives an

interrupt input of a microcontroller. The ERROR output is cleared after the internal error register

is read through the SPI interface. Connect a 10kΩ pullup resistor from ERROR to DVDD. The

MAX15500K/MAX15501K offer enhanced error mode logic. See the Error Handling section and

Figures 11a and 11b for more details.

6 DVDD

Digital Power-Supply Voltage Input. Apply either a 3V or 5V nominal voltage supply to DVDD.

DVDD powers the digital portion of the MAX15500/MAX15501. Bypass DVDD to DGND with a 0.1FF

capacitor as close as possible to the device.

7 DGND Digital Ground

8, 16,

24, 32 N.C. No Connection. Not internally connected.

9OUTDIS

Active-Low Output Disable Input. OUTDIS is an active-low logic input that forces the analog output

to 0A or 0V and puts the device in standby mode when connected to DGND. Connect OUTDIS to

DVDD for normal operation.

10 FSSEL

Full-Scale Select Input. Connect FSSEL to DVDD for the MAX15500 when applying a +4.096V

reference at REFIN. Connect FSSEL to DGND for the MAX15501 when applying a +2.50V reference

at REFIN.

11 FSMODE

Overrange Mode Select Input. Connect FSMODE to DVDD to set the output voltage to 105%FS

when the input voltage is equal to the full-scale value. Connect FSMODE to DGND to set the output

voltage to 120%FS when the input voltage is equal to the full-scale value. FSMODE has no effect in

current mode.

12, 15, 27 AGND Analog Ground

13 REFIN Reference Voltage Input. Connect REFIN to an external +4.096V reference for the MAX15500 or

+2.5V reference for the MAX15501. REFIN is used to set the offset for unipolar and bipolar modes.

14 AIN Analog Signal Input. The analog input signal range at AIN is from 0V to the nominal full scale of

+4.096V for the MAX15500 and +2.5V for the MAX15501.

17 AVSSO

Negative Output Driver Supply Voltage Input. AVSSO provides power to the driver output stage.

Bypass AVSSO to AVSS with a 0.1FF capacitor. Use diodes as shown in the Typical Operating

Circuit/Functional Diagram to ensure a voltage difference of 2V to 3.5V between AVSS and AVSSO.

18 COMP Output Amplifier Compensation Feedback Node. Connect a compensation capacitor from COMP to

OUT. See Table 10 for the recommended compensation capacitor values.

14 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Pin Description (continued)

PIN NAME FUNCTION

19 OUT Analog Output. The analog voltage or current output range at OUT is programmable. See Tables

1 to 4 for possible output range settings.

20 AVDDO

Positive Output Driver Supply Voltage Input. AVDDO provides power to the driver output stage.

Bypass AVDDO to AVDD with a 0.1FF capacitor. Use diodes as shown in the Typical Operating

Circuit/Functional Diagram to ensure a voltage difference of 2V to 3.5V between AVDD and

AVDDO.

21 SENSERP Sense Resistor Positive Connection. See the Typical Operating Circuit/Functional Diagram for the

typical connection.

22 SENSERN Sense Resistor Negative Connection. See the Typical Operating Circuit/Functional Diagram for the

typical connection.

23 SENSEVN Kelvin Sense Voltage Negative Input. See the Typical Operating Circuit/Functional Diagram for the

typical connection.

25 SENSEVP Kelvin Sense Voltage Positive Input. See the Typical Operating Circuit/Functional Diagram for the

typical connection.

26 AVDD Positive Analog Supply Voltage Input. Bypass AVDD to AGND with a 0.1FF capacitor.

28 AVSS Negative Analog Supply Voltage Input. Bypass AVSS to AGND with a 0.1FF capacitor.

29 MON Load Monitoring Output. MON provides an analog 0 to 3V output. See the Output Monitor section.

30 CS1 Active-Low SPI Chip-Select Input 1. See the SPI Interface section.

31 CS2 Active-Low SPI Chip-Select Input 2. See the SPI Interface section.

— EP Exposed Pad. Internally connected to AVSS. Connect to AVSS. Connect to a large copper area to

maximize thermal performance. Do not connect ground or signal lines through EP.

15Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Typical Operating Circuit/Functional Diagram

10kI

PGA

OFFSET

GENERATOR

DAC

2.5V/4.096V

REF

OUTPUT STAGE

SPI INTERFACE/

LOGIC I/O

SENSEVP

SENSERP

OUT

SENSERN

SENSEVN

AIN

REFIN

BROWNOUT

TEMP

MONITOR

DIN

SCLK

CS1

CS2

DOUT

DVDD

READY

OUTDIS

FSSEL*

FSMODE

AGND DGND

MON

AVDD AVDDODVDD

0.1FF0.1FF

0.1FF

POR

COMP

LOAD

SENSE

COMP

CABLE1

CABLE2

CABLE3

WRITE

SCLK

READ

GPIO

INT

DVDD

*FSSEL IS CONNECTED TO DGND FOR THE MAX15501.

LOAD

ADC

24V

AVSS AVSSO

0.1FF

-24V

MAX15500

MAX15501

ERROR

16 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Detailed Description

The MAX15500/MAX15501 output a programmable current

up to Q24mA or a voltage up to Q12V proportional to a

control signal at AIN. The devices operate from a dual

15V to 32.5V supply. The control voltage applied at AIN

is typically supplied by an external DAC with an output

voltage range of 0 to 4.096V for the MAX15500 and 0

to 2.5V for the MAX15501. The MAX15500/MAX15501

are capable of both unipolar and bipolar current and

voltage outputs. In current mode, the devices produce

currents of -1.2mA to +24mA or -24mA to +24mA. In

voltage mode, the devices produce voltages of -0.3V

to +6V, -0.6V to +12V, or Q12V. To allow for overrange

and underrange capability in unipolar mode, the transfer

function of the MAX15500/MAX15501 is offset such that

when the voltage at AIN is 5% of full scale, IOUT is 0mA

and VOUT is 0V. Once VAIN attains full scale, VOUT or

IOUT becomes full scale +5% or +20% depending on

the state of FSMODE. The devices are protected against

overcurrent and short-circuit conditions when OUT

goes to ground or a voltage up to Q32.5V. The devices

also monitor for overtemperature and supply brownout

conditions. The supply brownout threshold is programmable

between ±10V and ±24V in 2V increments.

The MAX15500/MAX15501 are programmed through an

SPI interface with daisy-chain capability. A device ready

logic output (READY) and two device select inputs (CS1

and CS2) facilitate a daisy-chain arrangement for multiple

device applications. The MAX15500/MAX15501 provide

extensive error reporting of short-circuit, open-circuit,

brownout, and overtemperature conditions through the

SPI interface and an additional open-drain interrupt

output (ERROR). The MAX15500/MAX15501 include an

analog 0 to 3V output (MON) to monitor the load condition

at OUT.

Analog Section

The MAX15500/MAX15501 support two output modes:

current and voltage. Each mode has different full-scale

output values depending on the state of FSMODE as

detailed in Table 1 through Table 4 and Figures 1 and 2.

Use the device configuration register in Table 6 to select

the desired voltage or current output range.

Startup

During startup, the MAX15500/MAX15501 output is set

to zero and all register bits are set to zero. The devices

remain in standby mode until they are configured

through the SPI interface.

Input Voltage Range

The input voltage full-scale level is selectable between

2.5V and 4.096V using logic input FSSEL. The MAX15500

is specified for a 0 to 4.096V input voltage range, while

the MAX15501 is specified for a 0 to 2.500V input volt-

age range. Connect FSSEL to DVDD to set the input

range to 0 to 4.096V for the MAX15500. Connect FSSEL

to DGND to set the input range to 0 to 2.500V for the

MAX15501.

Table 1. Output Values for FSMODE = DVDD,

Unipolar 5% Overrange

OUTPUT RANGE OUTPUT VALUES

VAIN = 5%FS VAIN = FS

0 to 20mA

(4mA to 20mA) 0mA 21mA

0 to 5V 0V 5.25V

0 to 10V 0V 10.5V

Table 2. Output Values for FSMODE = DGND,

Unipolar 20% Overrange

OUTPUT RANGE OUTPUT VALUES

VAIN = 5%FS VAIN = FS

0 to 20mA

(4mA to 20mA) 0mA 24mA

0 to 5V 0V 6V

0 to 10V 0V 12V

Table 3. Output Values for FSMODE = DVDD,

Bipolar 5% Overrange

OUTPUT RANGE OUTPUT VALUES

VAIN = 0V VAIN = FS

Q20mA -21mA +21mA

Q10V -10.5V +10.5V

Table 4. Output Values for FSMODE = DGND,

Bipolar 20% Overrange

OUTPUT RANGE OUTPUT VALUES

VAIN = 0V VAIN = FS

Q20mA -24mA +24mA

Q10V -12V +12V

17Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Output Monitor

The MON output provides an analog voltage signal

proportional to the output voltage in current mode and

proportional to the output current in voltage mode. Use

this signal to measure the system load presented to the

output. The full-scale signal on MON is 3V with a typical

accuracy of 10%. The signal range is typically 1.5V to 3V

in unipolar mode and 0 to 3V in bipolar mode.

In current mode, the MAX15500/MAX15501 program IOUT

and monitor the voltage at SENSERN.

VMON = 1.425V + (VSENSERN/20)

RLOAD = ((VMON - 1.425V) x 20)/IOUT(PROGRAMMED)

In voltage mode, the MAX15500/MAX15501 program

VOUT and monitor IOUT.

VMON = 1.521V + 62.4 x ILOAD

RLOAD = VOUT(PROGRAMMED)/((VMON - 1.521V)/62.4)

Error Handling

Many industrial control systems require error detection and

handling. The devices provide extensive error status reporting.

An open-drain interrupt flag output, ERROR, pulls low

when an error condition is detected. An error register

stores the error source. Reading the error register once

resets the ERROR pin but not the error register itself,

allowing the system to determine the source of the error

and take steps to fix the error condition. After the error

condition has been fixed, read the error register for

the second time to allow the device to clear the error

if the error register has been cleared. If another error

occurs after the first read, ERROR goes low again. More

information on reading and clearing the error register is

described in the SPI Interface section.

When an output short-circuit or output open-load error

occurs and disappears before the error register is read,

the intermittent bit is set in the error register. The intermittent

bit does not assert for brownout and overtemperature error

conditions. The MAX15500/MAX15501 and MAX15500K/

MAX15501K offer different error handling for open

circuits and short circuits. See the individual sections,

Figure 11a, and Figure 11b for more details.

Error Conditions

Output Short Circuit

The output short-circuit error bit asserts when the output

current exceeds 30mA (typ) for longer than 260ms. In

current mode, this error occurs when the sense resistor

is shorted and the sense voltage is not equal to 0V. In

voltage mode, this error occurs when the load is shorted

to the supply or ground. The short-circuit error activates

the intermittent bit in the error register if the error goes

away before the error register is read.

The MAX15500/MAX15501 only asserts the short-circuit

flag when a short is detected and an open circuit is not

detected.

AIN

OUT

OR I

OUT

FS + 20%

FS + 5%

5%FS

FSMODE = DGND

FSMODE = DVDD

Figure 1. Unipolar Transfer Function

AIN

OUT

OR I

OUT

FS + 20%

FS + 5%

-FS - 20%

-FS - 5%

FSMODE = DGND

FSMODE = DVDD

50%FS

-FS

Figure 2. Bipolar Transfer Function

18 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Output Short-Circuit: Voltage Mode Only

(MAX15500K/MAX15501K)

The output short-circuit error bit asserts when the output

current exceeds 30mA (typ) for longer than 260ms in

voltage mode only. This error occurs when the load is

shorted to the supply or ground. The short-circuit error

activates the intermittent bit in the error register if the

error goes away before the error register is read.

Output Open Load (MAX15500/MAX15501)

The open-circuit error bit activates when VOUT is within

30mV of AVDDO or AVSSO and there is no short-circuit

current in current mode for longer than 260ms. This error

activates the intermittent bit in the error register if the

error goes away before the error register is read.

The MAX15500/MAX15501 open-circuit flag is active

when both a short circuit and open circuit are detected.

The MAX15500/MAX15501 does not flag open circuit

when the load current is between -3.5mA (typ) to +3.5mA

(typ). Figure 11a shows the full range of the open circuit

detection range and Figure 11b offers a zoomed in view.

The MAX15500/MAX15501 are shown in the red lines.

Output Open Load (MAX15500K/MAX15501K)

The open-circuit error bit activates when VOUT is within

30mV of AVDDO or AVSSO for longer than 260ms. This

error activates the intermittent bit in the error register if

the error goes away before the error register is read.

The MAX15500K/MAX15501K does not flag open circuit

when the load current is between -0.5mA (typ) to +0.5mA

(typ). Figure 11a shows the full range of the open circuit

detection range and Figure 11b offers a zoomed in view.

The MAX15500K/MAX15501K are shown in the green

lines.

Internal Overtemperature

The MAX15500/MAX15501 enter standby mode if the die

temperature exceeds +150NC and the overtemperature

protection is enabled as shown in Table 6. When the die

temperature cools down below +140NC, the error regis-

ter must be read back twice to resume normal operation.

The devices provide a 10NC hysteresis. The MAX15500/

MAX15501 and MAX15500K/MAX15501K all trigger the

overtemperature ERROR flag in the same manner.

Brownout

The brownout-error bit activates when the supply voltage

(VAVDD or VAVSS) falls below the brownout threshold.

The threshold is programmable between Q10V to Q24V

in 2V steps. See Table 6 for details. The MAX15500/

MAX15501 provide a 2% hysteresis for the brownout

threshold. The accuracy of the threshold is typically

within 10%. During power-up, ERROR can go low and

the brownout register is set. Users need to read out the

error register twice to clear all the error register bits and

reset ERROR to high. The MAX15500/MAX15501 and

MAX15500K/MAX15501K all trigger the overtemperature

ERROR flag in the same manner.

Output Protection

The MAX15500/MAX15501 supply inputs (AVDD, AVDDO,

AVSS, and AVSSO) and sense inputs (SENSERN,

SENSERP, SENSEVN, and SENSEVP) are protected

against voltages up to Q35V with respect to AGND. See

the Typical Operating Circuit/Functional Diagram for the

recommended supply-voltage connection.

SPI Interface

Standard SPI Implementation

The MAX15500/MAX15501 SPI interface supports daisy-

chaining. Multiple MAX15500/MAX15501 devices can

be controlled from a single 4-wire SPI interface. The

MAX15500/MAX15501 feature dual CS_ inputs and

an added digital output, READY, that signals when

the devices finish processing the SPI frame. CS1 and

CS2 are internally OR-ed. Pull both CS1 and CS2 to

logic-low to activate the MAX15500/MAX15501. For a

daisy-chained application, connect the CS1 input of

all of the devices in the chain to the CS driver of the

microcontroller. Connect the CS2 input of the first device

to ground or to the CS driver of the microcontroller.

Connect CS2 of the remaining devices to the READY

output of the preceding device in the chain. The READY

output of the last device in the chain indicates when

all slave devices in the chain are configured. Connect

the READY output of the last device in the chain to the

microcontroller. Use the open-drain ERROR output as a

wired-OR interrupt. See Figures 3 to 6.

19Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Figure 3. Single Connection (Compatible with Standard SPI)

DWRITE

SCLK

DREAD

CS1

DOUT

SCLK

DIN

ERROR

INT

CS1

CSn

TO OTHER CHIPS/CHAINS

READY

MONITOR

OPTIONAL CONNECTION

CS2

PULLUP MAX15500

MAX15501

Figure 4. Alternate Single Connection (Compatible with Standard SPI)

Figure 5. Daisy-Chain Connection (Compatible with Standard SPI)

DWRITE

SCLK

DREAD

CS1

DOUT

SCLK

DIN

ERROR

INT

CS1

CSn

TO OTHER CHIPS/CHAINS

READY

MONITOR

OPTIONAL CONNECTION

CS2

PULLUP MAX15500

MAX15501

DWRITE

SCLK

DREAD

CS1

DOUT

SCLK

DIN

ERROR

INT

CS1

CSn

TO OTHER CHIPS/CHAINS

READY

MONITOR

OPTIONAL CONNECTION

CS2

PULLUP

MAX15500

MAX15501

CS1

DOUT

SCLK

DIN

ERROR

READY

CS2

MAX15500

MAX15501

CS1

DOUT

SCLK

DIN

ERROR

READY

CS2

MAX15500

MAX15501

20 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Modified SPI Interface Description

The SCLK, DIN, and DOUT of the MAX15500/MAX15501

assume standard SPI functionality. While the basic func-

tion of the MAX15500/MAX15501 CS_ inputs is similar

to the standard SPI interface protocol, the management

of the CS_ input within the chain is modified. When both

CS_ inputs are low, the MAX15500/MAX15501 assume

control of the DOUT line and continue to control the line

until the data frame is finished and READY goes low

(Figure 9). Once a complete frame is processed and the

READY signal is issued, the devices do not accept any

data from DIN, until either CS1 or CS2 rises and returns

low. A new communication cycle is initiated by a sub-

sequent falling edge on CS1 or CS2. When either CS1

or CS2 is high, the MAX15500/MAX15501 SPI interface

deactivates, DOUT returns to a high-impedance mode,

READY (if active) clears, and any partial frames not yet

processed are ignored.

READY asserts once a valid frame is processed allowing

the next device in the chain to begin processing the sub-

sequent frame. A valid frame consists of 16 SCLK cycles

following the falling edge of CS_. Once READY asserts,

it remains asserted until either CS_ rises, completing the

programming of the chain.

Figure 6. Daisy-Chain Terminating (Compatible with Standard SPI)

DWRITE

SCLK

DREAD

CS1

DOUT

SCLK

DIN

ERROR

INT

CS1

CSn

TO OTHER CHIPS/CHAINS

SPI DEVICE

READY

CS2

PULLUP

MAX15500

MAX15501

CS1

DOUT

SCLK

DIN

ERROR

READY

CS2

MAX15500

MAX15501

DOUT

SCLK

DIN

21Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

The MAX15500/MAX15501 relinquish control of DOUT

once the devices process the frame(s). DOUT remains

high impedance when the SPI interface continues to hold

CS_ low beyond the required frame(s). Install a pullup/

puldown resistor at the DOUT line to maintain the desired

state when DOUT goes high impedance.

Single Device SPI Connection

For applications using a single MAX15500 or MAX15501,

connect both CS1 and CS2 inputs to the device-select

driver of the host microcontroller. Alternatively, connect

one of the CS_ inputs to the device-select driver of the

host microcontroller and the other CS_ to DGND. Both

methods allow standard SPI interface operation. See

Figures 3 and 4.

Daisy-Chain SPI Connection

The MAX15500/MAX15501-modified SPI interface allows

a single SPI master to drive multiple devices in a daisy-

chained configuration, saving additional SPI channels for

other devices and saving cost in isolated applications.

Figure 5 shows multiple MAX15500/MAX15501 devices

connected in a daisy chain. The chain behaves as a

single device to the microcontroller in terms of timing

with an expanded instruction frame requiring 16 SCLK

cycles per device for complete programming. No timing

parameters are affected by the READY propagation as

all devices connect to the microcontroller chip-select

through the CS1 inputs.

A chain of MAX15500/MAX15501 devices can be terminated

with any standard SPI-compatible single device without

a READY output. The MAX15500/MAX15501 portion

of the chain continues to display timing parameters

comparable to a single device. See Figure 6.

When using the MAX15500/MAX15501 with mixed

chains, the connections could require some modification

to accommodate the interfaces of the additional devices

in the chain. Construct the daisy chain as shown in

Figure 7 when using devices with similar READY outputs

but without dual CS_ inputs such as the MAX5134 quad

16-bit DAC. The chain is subject to timing relaxation for

parameters given with respect to CS_ rising edges to

accommodate READY propagation to and through con-

secutive MAX5134 devices.

The chain can begin and terminate with either device

type. Each MAX5134 or MAX15500/MAX15501 device

in the chain could be replaced by a subchain of similar

devices. If the chain is terminated with a standard SPI

device, omit the optional connection from READY to the

monitor input on the microcontroller. The MAX15500/

MAX15501 portion of the chain continues to display tim-

ing parameters comparable to a single device.

SPI Digital Specifications and Waveforms

Figures 8, 9, and 10 show the operation of the modified

SPI interface. The minimum programming operation

typically used in single device applications is 16 SCLK

periods, the minimum for a valid frame. This cycle can

also represent the operation of the final device in a chain.

The extended programming operation is typically used

for devices in daisy-chained applications. In this case,

READY drives the chip-select input of the subsequent

device in the chain. The next device in the chain

begins its active frame on the 16th SCLK falling edge in

response to READY falling (latching DIN[13] on the 17th

SCLK falling edge, if present).

Aborted SPI Operations

Driving a CS_ input high before a valid SPI frame is

transmitted to the device can cause an erroneous com-

mand. Avoid driving CS_ high before a valid SPI frame is

transmitted to the device. See Figures 9 and 10 for valid

SPI operation timing.

SPI Operation Definitions

Input data bits DIN[13:11] represent the SPI command

address while DIN[9:0] represent the data written to

or read from the command address. The command

address directs subsequent input data to the proper

internal register for setting up the behavior of the device

and selects the correct status data for readback through

DOUT. Command address 0h points to a no-op com-

mand and does not impact the operation of the device.

DOUT is active during this operation and reads back

00h. Command address 1h points to the configuration

Device configuration takes effect following the 14th

SCLK falling edge. DOUT activates and remains low dur-

ing this operation. Command addresses 4h and 5h point

to readback commands of the MAX15500/MAX15501.

Readback commands provide configuration and error

internal operation of the device. Command addresses

2h, 3h, 6h, and 7h are reserved for future use. Table 5

shows the list of commands.

Device Configuration Operation

Table 6 shows the function of each bit written to the con-

figuration register 1h. Table 7 shows the data readback

registers.

22 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Figure 7. Mixed MAX15500/MAX15501 and MAX5134 Daisy-Chain Connections

Figure 8. Minimum SPI Programming Operation (Typically for Single Device Applications)

DWRITE

SCLK

DREAD

CS1

DOUT

SCLK

DIN

ERROR

INT

CS1

CSn

TO OTHER CHIPS/CHAINS

READY

MONITOR

OPTIONAL CONNECTION

CS2

PULLUP MAX15500

MAX15501

CS1

DOUT

SCLK

DIN

ERROR

READY

CS2

MAX15500

MAX15501

SCLK

DIN

READY

MAX5134

123456789

10 11 12 13 14 15 16

DIN13 DIN12 DIN11 DIN9 DIN8 DIN7 DIN6 DIN5 DIN4 DIN3 DIN2 DIN1X

XX X

HIGH-Z

ACTIVE FRAME

CS_

DOUT

SCLK

DIN

CSH

CSW

CSS

DOE

DOH

DOT

DOZ

COMMAND EXECUTED

DIN10 DIN0

DOUT9 DOUT8 DOUT7 DOUT6 DOUT5 DOUT4 DOUT3 DOUT2 DOUT1 DOUT0

ERROR REGISTER UPDATED,

ERROR RE-EVALUATED

23Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Readback Operations

Write to the command addresses 4h or 5h to read back the

configuration register data or the internal error information

through DOUT[9:0]. For error readback operations, each

bit corresponds to a specific error condition, with multiple

bits indicating multiple error conditions present.

Intermittent Errors

An intermittent error is defined as an error that is detected

and is resolved before the error register is read back.

When the error is resolved without intervention, the inter-

mittent bit (bit 9) is set. The output short-circuit and output

open-load errors trigger the intermittent bit. Internal over-

temperature and supply voltage brownout do not trigger

the intermittent bit.

Error Reporting Applications

The ERROR output is typically connected to an inter-

rupt input of the system microcontroller. The MAX15500/

MAX15501 only issue an interrupt when a new error con-

dition is detected. The devices do not issue interrupts

when errors (either individual or multiple) are resolved

or when already reported errors persist. The system

microcontroller resets ERROR when the system micro-

controller reads back the error register. ERROR does not

assert again unless a different error occurs.

Figure 9. Extended SPI Programming Operation (Daisy-Chained Applications)

Figure 10. Aborted SPI Programming Operation (Invalid, Showing tCSDOZ and Internal Activity)

123456789

10 11 12 13 14 15 16 17

DIN13 DIN12 DIN11 DIN9 DIN8 DIN7 DIN6 DIN5 DIN4 DIN3 DIN2 DIN1X

XX X

HIGH-Z

ACTIVE FRAME

CS_

DOUT

SCLK

DIN

CSH

CSV

CSR

CSS

DOE

DOH

DOT

DOZ

DIN10 DIN0

DOUT9 DOUT8 DOUT7 DOUT6 DOUT5 DOUT4 DOUT3 DOUT2 DOUT1 DOUT0

READY

123456789

10 11 12 13 14 15 16

HIGH-Z

CS_

DOUT

SCLK

CSH

CSS

DOE

CSDOZ

ERROR REGISTER UPDATED,

ERROR RE-EVALUATED

OPERATION ABORTED

DOUT9

24 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Figure 11a. Diagram Showing the MAX15500/MAX15501

“Plain” (Red) and the MAX15500K/MAX15501K (Teal) Open-

Circuit Detection Windows

Figure 11b. Zoomed In Diagram Showing the MAX15500/

MAX15501 “Plain” (Red) and the MAX15500K/MAX15501K

(Teal) Open-Circuit Detection Windows

25Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Table 5. SPI Commands

Table 6. Configuration Register

Note: Modes 2h and 3h are functionally identical.

Table 7. Readback Operations and Formatting

LOCATION FUNCTION DESCRIPTION

DIN[9:7] Mode[2:0]

Sets device operating mode.

000 Mode[0]: Standby 100 Mode[4]: Standby

001 Mode[1]: Bipolar current: Q20mA 101 Mode[5]: Bipolar voltage: Q10V

010 Mode[2]: Unipolar current: 0 to 20mA 110 Mode[6]: Unipolar voltage: 0 to 10V

011 Mode[3]: Unipolar current: 4mA to 20mA 111 Mode[7]: Unipolar voltage: 0 to 5V

DIN[6:4] VBOTH[2:0]

Sets supply voltage brownout threshold for error reporting.

000: Q10V 100: Q18V

001: Q12V 101: Q20V

010: Q14V 110: Q22V

011: Q16V 111: Q24V

DIN[3] Thermal

shutdown 0 = thermal protection off. 1 = thermal protection on.

DIN[10],

DIN[2:0] — Reserved

DOUT BITS DESCRIPTION

COMMAND ADDRESS DIN[13:11] = 101. READBACK DEVICE CONFIGURATION REGISTER

DOUT[9:0] See configuration register details in Table 6.

COMMAND ADDRESS DIN[13:11] = 100. READBACK ERROR REGISTER

DOUT[9] Output Intermittent Fault. For details, see the Error Handling section.

DOUT[8]

Output Short Circuit. Output short circuit. In the MAX15500/MAX15501, this bit asserts when IOUT > 30mA in

voltage and current modes for longer than 260ms. In the MAX15500K/MAX15501K, this bit asserts when Iout

> 30mA for longer than 260ms (in voltage mode only).

DOUT[7]

Output Open Load. In the MAX15500/MAX15501, this bit asserts when VOUT is within 30mV of AVDDO or

AVSSO and there is no short-circuit condition for longer than 260ms. In the MAX15500K/MAX15501K, the

output open load bit asserts when VOUT is within 30mV of AVDDO or AVSSO for longer than 260ms.

DOUT[6] Internal Overtemperature. This bit asserts when the die temperature exceeds +150NC.

DOUT[5] Supply Brownout. This bit asserts when either supply has entered the brownout limits. See Table 6 for details.

DOUT[4:0] Reserved

COMMAND

ADDRESS

DIN[13:11]

NAME DESCRIPTION

000 No-op No operation.

001 Write configuration Write device configuration register. See Table 6 for details.

010 Reserved Reserved, no operation.

011 Reserved Reserved, no operation.

100 Read error Read error register status. See Table 7 for details.

101 Read configuration Read device configuration register. See Table 6 for details.

110 Reserved Reserved, no operation.

111 Reserved Reserved, no operation.

26 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Since the MAX15500/MAX15501 do not use a continuous

clock signal, the SPI read cycles are used to cycle the

error detection and reporting logic. Continue to poll the

device until the error readback reports an all clear status

when resolving single or multiple errors. See below for

examples of typical error handling situations and the

effects of the SPI read operations.

1) Error resolved by the system.

a) The MAX15500/MAX15501 detect an error condi-

tion and ERROR asserts.

b) The host controller reads the error register for the

first time. This has the effect of resetting ERROR.

The data indicates to the host processor which

error is active.

c) The host processor resolves the error successfully.

d) The host processor reads the error register for the

second time. The data still shows that the error is

present as the error persisted for some time after

step b and before step c. If the error is either an

open load or short circuit, the intermittent bit is set.

An overtemperature or a brownout does not set the

intermittent bit. Reading the register a second time

resets the register.

e) The host reads the error register for a third time.

The data now shows the error is resolved and

future occurrences of this error will trigger ERROR

assertion.

2) Error resolved before the host processor reads error

a) The MAX15500/MAX15501 detect an error condi-

tion and ERROR asserts, but the error resolves

itself.

b) The host controller reads the error register for the

first time resetting ERROR. The data indicates to

the host processor which error is active. The data

also indicates to the host that the error has been

resolved since the intermittent bit is set.

c) The host processor reads the error register for the

second time. The data still shows that the error is

active. If the error is for an output fault, the data

also indicates to the host that the error has been

resolved since the intermittent bit is set. Reading

the register a second time resets the register.

3) An error that cannot be resolved.

a) The MAX15500/MAX15501 detect an error condi-

tion and ERROR asserts.

b) The host controller reads the error register for the

first time and resets ERROR. The data indicates to

the host processor which error is active.

c) The host processor takes action to resolve the

error unsuccessfully.

d) The host processor reads the error register for the

second time. The data still shows that the error is

present.

e) The host processor reads the error for the third

time. The data show the error to be unresolved.

ERROR does not respond to the same error until

the error is resolved and reported. ERROR asserts

if different errors occur.

Applications Information

Setting the Output Gain in Current Mode

In current mode, there is approximately 1.0V across the

current-sensing resistors at full scale. The current sens-

ing resistor sets the gain and is calculated as follows:

RSENSE = VSENSE_FS/IMAX

where VSENSE_FS is the full-scale voltage across the

sense resistor.

See Table 8 for values of VSENSE_FS.

Output Gain in Voltage Mode

The output gain in voltage mode is fixed as shown in

Table 9.

Selection of the Compensation

Capacitor (CCOMP)

Use Table 10 to select the compensation capacitor.

Layout Considerations

In the current-mode application, use Kelvin and a short

connection from SENSERN and SENSERP to the RSENSE

terminals to minimize gain-error drift. Balance and mini-

mize all analog input traces for optimum performance.

27Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Table 8. Recommended Current Setting Components

Table 9. Full-Scale Output Voltages

VREFIN

(V)

OVERRANGE

(%)

BIPOLAR/

UNIPOLAR MODE VSENSE_FS

(V)

RSENSE

(I)

IOUT

(mA)

IDEAL

GAIN

IDEAL TRANSFER

FUNCTION

4.096

+20

Unipolar 2 1.02144 42.2 24.205 0.2625/42.2 IOUT = 0.2625 x (VAIN -

0.05 x VREFIN)/42.2

Bipolar 1 Q1.024 42.2 Q24.27 0.5/42.2 IOUT = 0.5 x (VAIN - 0.5 x

VREFIN)/42.2

Unipolar 2 1.02144 48.7 20.97 0.2625/48.7 IOUT = 0.2625 x (VAIN -

0.05 x VREFIN)/48.7

Bipolar 1 Q1.024 48.7 Q21.03 0.5/48.7 IOUT = 0.5 x (VAIN - 0.5 x

VREFIN)/48.7

2.500

+20

Unipolar 2 1.009375 41.2 24.5 0.425/41.2 IOUT = 0.425 x (VAIN -

0.05 x VREFIN)/41.2

Bipolar 1 Q141.2 Q24.27 0.8/41.2 IOUT = 0.8 x (VAIN - 0.5 x

VREFIN)/41.2

Unipolar 2 1.009375 47.5 21.25 0.425/47.5 IOUT = 0.425 x (VAIN -

0.05 x VREFIN)/47.5

Bipolar 1 Q147.5 Q21.05 0.8/47.5 IOUT = 0.8 x (VAIN - 0.5 x

VREFIN)/47.5

VREFIN

(V)

OVERRANGE

(%)

BIPOLAR/

UNIPOLAR MODE IDEAL

GAIN

IDEAL

TRANSFER FUNCTION

IDEAL VOUT

(V)

4.096

+20 Unipolar 7 1.5625 VOUT = 1.5625 x (VAIN - 0.05 x VREFIN) 6.08

6 3.125 VOUT = 3.125 x (VAIN - 0.05 x VREFIN) 12.16

Bipolar 5 6.0 VOUT = 6.0 x (VAIN - 0.5 x VREFIN)Q12.288

+5 Unipolar 7 1.375 VOUT = 1.375 x (VAIN - 0.05 x VREFIN) 5.3504

6 2.75 VOUT = 2.75 x (VAIN - 0.05 x VREFIN) 10.7008

Bipolar 5 5.25 VOUT = 5.25 x (VAIN - 0.5 x VREFIN)Q10.752

2.500

+20 Unipolar 7 2.5125 VOUT = 2.5125 x (VAIN - 0.05 x VREFIN) 5.96719

6 5.0625 VOUT = 5.0625 x (VAIN - 0.05 x VREFIN) 12.0234

Bipolar 5 9.6 VOUT = 9.6 x (VAIN - 0.5 x VREFIN)Q12

+5 Unipolar 7 2.175 VOUT = 2.175 x (VAIN - 0.05 x VREFIN) 5.16563

6 4.425 VOUT = 4.425 x (VAIN - 0.05 x VREFIN) 10.5094

Bipolar 5 8.4 VOUT = 8.4 x (VAIN - 0.5 x VREFIN)Q10.5

28 Maxim Integrated

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Table 10. Recommended Compensation Capacitor for Various Load Conditions

Chip Information

PROCESS: BiCMOS

Package Information

For the latest package outline information and land patterns

(footprints), go to www.maximintegrated.com/packages. Note

that a “+”, “#”, or “-” in the package code indicates RoHS status

only. Package drawings may show a different suffix character, but

the drawing pertains to the package regardless of RoHS status.

CL = Load capacitance.

RL = Load resistance.

LL = Load inductance.

CCOMP = Compensation capacitance.

PACKAGE

TYPE

PACKAGE

CODE

OUTLINE

NO.

LAND

PATTERN NO.

32 TQFN-EP T3255+4 21-0140 90-0012

MODE CL (F) RL (kI)LL (H) CCOMP (F)

Voltage 0 to 1n 1 0 0

Voltage 1n to 100n 1 0 1n

Voltage 100n to 1F1 0 2.2n

Voltage 1F to 100F1 0 4.7n

Current 0 to 1n 20 to 750 0 to 20F0

Current 0 to 1n 20 to 750 20F to 1m 2.2n

Current 0 to 1n 20 to 750 1m to 50m 100n

Current 1n to 100n 20 to 750 0 to 20F1n

Current 1n to 100n 20 to 750 20F to 1m 2.2n

Current 1n to 100n 20 to 750 1m to 50m 100n

Current 100n to 1F20 to 750 0 to 20F2.2n

Current 100n to 1F20 to 750 20F to 1m 2.2n

Current 100n to 1F20 to 750 1m to 50m 100n

Current 1F to 100F20 to 750 0 to 20F2.2n

Current 1F to 100F20 to 750 20F to 1m 2.2n

Current 1F to 100F20 to 750 1m to 50m 100n

Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent

licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and

max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000 29

Industrial Analog Current/

Voltage-Output Conditioners

MAX15500/MAX15501

Revision History

REVISION

NUMBER

REVISION

DATE DESCRIPTION PAGES

CHANGED

0 7/09 Initial release —

1 2/11 Corrected description of DOUT pin in Pin Description section 13

2 10/15 Added new figures and text to Applications section and added “K”

versions for added ERROR pin functionality. 1, 13, 17, 18, 23, 24