General Description
The DS1624 consists of two separate functional units: a
256-byte nonvolatile E2 memory and a direct-to-digital
temperature sensor.
The nonvolatile memory is made up of 256 bytes of E2
memory. This memory can be used to store any type of
information the user wishes. These memory locations are
accessed through the 2-wire serial bus.
The direct-to-digital temperature sensor allows the
DS1624 to measure the ambient temperature and report
the temperature in a 12-bit word with 0.0625°C resolu-
tion. The temperature sensor and its related registers are
accessed through the 2-wire serial interface. Figure 1
shows a block diagram of the DS1624.
Benets and Features
Reduces Component Count with Integrated
Temperature Sensor and Nonvolatile E2 Memory
Measures Temperatures from -55°C to +125°C in
0.0625°C Increments
±0.5°C Accuracy from 0°C to 70°C
256 Bytes of E2 Memory for Storing Information
Such as Frequency Compensation Coefcients
No External Components
Easy-to-Use 2-Wire Serial Interface
Temperature is Read as a 12-Bit Value
(2-Byte Transfer)
Available in 8-Pin SO and DIP Packages
Ordering Information appears at end of data sheet.
19-6288; Rev 5; 8/15
Figure 1. Block Diagram
STATUS REGISTER AND
CONTROL LOGIC
TEMPERATURE
SENSOR
EEPROM MEMORY
(256 BYTES)
V
DD
GND
SCL
SDA
A0
A1
A2
DS1624
ADDRESS AND
I/O CONTROL
DS1624 Digital Thermometer and Memory
Voltage Range on Any Pin Relative to Ground ....-0.5V to +6.0V
Continuous Power Dissipation (TA = +70°C)
PDIP (derate 9.10mW/°C above +70°C) ................727.30mW
Operating Temperature Range ......................... -55°C to +125°C
Storage Temperature Range ............................ -55°C to +125°C
Soldering Temperature (reflow) ....................................... +260°C
Lead Temperature (soldering, 10s) .................................+300°C
PDIP
Junction-to-Ambient Thermal Resistance JA) ........110°C/W Junction-to-Case Thermal Resistance JC) ...............40°C/W
(Note 1)
(VDD = 2.7V to 5.5V, TA = -55°C to +125°C, unless otherwise noted.) (Note 3)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Supply Voltage VDD (Note 2) 2.7 5.0 5.5 V
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Thermometer Error TERR
0°C to +70°C ±0.5 °C
-55°C to +125°C ±2.0
Thermometer Resolution 12-bit 0.0625 °C
Low-Level Input Voltage VIL -0.3 0.3 x VDD V
High-Level Input Voltage VIH 0.7 x VDD VDD + 0.3 V
Pulse Width of Spikes That Must
Be Suppressed by the Input Filter tSP Fast mode 0 50 ns
Low-Level Output Voltage (SDA) VOL1 3mA sink current (Note 2) 0 0.4 V
VOL2 6mA sink current (Note 2) 0 0.6
Input Current Each I/O Pin 0.4 < VI/O < 0.9VDD (Note 4) -1 +1 µA
I/O Capacitance CI/O 10 pF
Active Supply Current ICC
Temperature conversion 1250
µAE2 write (Notes 5, 6) 400
Communication only 125
Standby Supply Current ISTBY (Notes 5, 6, 7) 1 3 µA
DS1624 Digital Thermometer and Memory
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Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer
board. For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Absolute Maximum Ratings
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods of time may affect device reliability.
Package Thermal Characteristics
DC Electrical Characteristics
Recommended Operating Conditions
(VDD = 2.7V to 5.5V, TA = -55°C to +125°C, unless otherwise noted. All values referred to VIH = 0.9VDD and VIL = 0.1VDD.)
Note 2: All voltages are referenced to ground.
Note 3: Limits are 100% production tested at TA = +25°C and/or TA = +85°C. Limits over the operating temperature range and
relevant supply voltage are guaranteed by design and characterization.
Note 4: I/O pins of fast mode devices must not obstruct the SDA and SCL lines if VDD is switched off.
Note 5: ICC specified with SDA pin open.
Note 6: ICC specified with VCC at 5.0V and SDA, SCL = 5.0V, 0°C to +70°C.
Note 7: EEPROM inactive, temperature sensor in shutdown mode.
Note 8: For example, if CB = 300pF, then tR(MIN) = tF(MIN) = 50ns.
Note 9: Write occurs between 0°C and +70°C.
Note 10: See the timing diagram (Figure 2). All timing is referenced to 0.9VDD and 0.1VDD.
Note 11: After this period, the first clock pulse is generated.
Note 12: A fast mode device can be used in a standard mode system, but the requirement tSU:DAT 250ns must then be met. This
is automatically the case if the device does not stretch the low period of the SCL signal. If such a device does stretch the
low period of the SCL signal, it must output the next data bit to the SDA line tR(MAX) + tSU:DAT = 1000 + 250 = 1250ns
before the SCL line is released.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Temperature Conversion Time tTC 200 ms
EEPROM Write Cycle Time tWR 0°C to +70°C (Note 8) 50 ms
EEPROM Endurance NEEWR
-20°C to +70°C (Note 9) 10k 20k Write
Cycles
TA = +25°C 40k 80k
EEPROM Data Retention tEEDR -40°C to +70°C 10 20 Years
SLK Clock Frequency fSCL
Fast mode (Note 10) 0 400 kHz
Standard mode 0 100
Bus Free Time Between a STOP
and START Condition tBUF
Fast mode (Note 10) 1.3 µs
Standard mode 4.7
Hold Time (Repeated)
START Condition tHD:STA
Fast mode (Notes 10, 11) 0.6 µs
Standard mode 4.0
Low Period of SCL Clock tLOW
Fast mode (Note 10) 1.3 µs
Standard mode 4.7
High Period of SCL Clock tHIGH
Fast mode (Note 10) 0.6 µs
Standard mode 4.0
Setup Time for a Repeated START
Condition tSU:STA
Fast mode (Note 10) 0.6 µs
Standard mode 4.7
Data Hold Time tHD:DAT
Fast mode (Note 10) 0 0.9 µs
Standard mode 0 0.9
Data Setup Time tSU:DAT
Fast mode (Notes 10, 11,
12)
100 ns
Standard mode 250
Rise Time of Both SDA and SCL
Signals tR
Fast mode (Notes 8, 10, 12) 20 + 0.1CB300 ns
Standard mode 20 + 0.1CB1000
Fall Time of Both SDA and SCL
Signals tF
Fast mode (Notes 8, 10, 12) 20 + 0.1CB300 ns
Standard mode 20 + 0.1CB300
Setup Time for STOP Condition tSU:STO
Fast mode (Note 10) 0.6 µs
Standard mode 4.0
Capacitive Load for Each Bus Line CB400 pF
Input Capacitance CI5 pF
DS1624 Digital Thermometer and Memory
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AC Electrical Characteristics
NOTE: THE DS1624 DOES NOT DELAY THE SDA LINE INTERNALLY WITH RESPECT TO SCL FOR ANY LENGTH OF TIME
SDA
STOP
SCL
START REPEATED
START
t
BUF
t
LOW
t
R
t
HD:STA
t
F
t
HD:STA
t
SP
t
HD:DAT
t
HIGH
t
SU:DAT
t
SU:STA
t
SU:STO
DS1624 DIGITAL THERMOMETER AND THERMOSTAT TEMPERATURE READING ERROR
5
4
3
2
1
-1
-2
-3
-55 -35 -15
0
5 25 45 65 85 105 125
TYPICAL
ERROR
LOWER LIMIT
SPECIFICATION
ERROR (°C)
TEMPERATURE (°C)
DS1624 Digital Thermometer and Memory
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Timing Diagram
Typical Performance Curve
Detailed Description
2-Wire Serial Data Bus
The DS1624 supports a bidirectional two-wire bus and
data transmission protocol. A device that sends data onto
the bus is defined as a transmitter, and a device receiving
data as a receiver. The device that controls the message
is called a “master.” The devices that are controlled by
the master are “slaves.” The bus must be controlled by
a master device which generates the serial clock (SCL),
controls the bus access, and generates the START and
STOP conditions. The DS1624 operates as a slave on
the two-wire bus. Connections to the bus are made via
the open-drain I/O lines SDA and SCL. The following bus
protocol has been defined (see Figure 2):
Data transfer can be initiated only when the bus is
not busy.
During data transfer, the data line must remain stable
whenever the clock line is high. Changes in the data
line while the clock line is high are interpreted as
control signals.
Accordingly, the following bus conditions have been
defined:
Bus Not Busy: Both data and clock lines remain high.
Start Data Transfer: A change in the state of the data
line, from high to low, while the clock is high, defines a
START condition.
Stop Data Transfer: A change in the state of the data
line, from low to high, while the clock line is high, defines
the STOP condition.
Data Valid: The state of the data line represents valid
data when, after a START condition, the data line is stable
for the duration of the high period of the clock signal. The
data on the line must be changed during the low period of
the clock signal. There is one clock pulse per bit of data.
Each data transfer is initiated with a START condition and
terminated with a STOP condition. The number of data
bytes transferred between START and STOP conditions
is not limited, and is determined by the master device.
Pin Description
PIN NAME FUNCTION
1 SDA Data Input/Output Pin for 2-Wire Serial
Communication Port
2 SCL Clock Input/Output Pin for 2-Wire Serial
Communication Port
3 N.C. No Connection. No Internal Connection.
4 GND Ground
5 A2 Address Input
6 A1 Address Input
7 A0 Address Input
8 VDD 2.7V to 5.5V Input Power-Supply Voltage
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2
SDA
SCL
N.C.
GND
V
DD
A0
A1
A2
DS1624
SO (208 mils)
+
1
4
3
7
8
5
6
TOP VIEW
N.C.
GND A2
SDA
SCL A0
A1
V
DD
PDIP (300 mils)
4
2
3
1
6
5
8
7
DS1624
Pin Congurations
The information is transferred byte-wise and each receiv-
er acknowledges with a ninth bit.
Within the bus specifications a standard mode (100kHz
clock rate) and a fast mode (400kHz clock rate) are
defined. The DS1624 works in both modes.
Acknowledge: Each receiving device, when addressed,
is obliged to generate an acknowledge after the reception
of each byte. The master device must generate an extra
clock pulse, which is associated with this acknowledge bit.
A device that acknowledges must pull down the SDA line
during the acknowledge clock pulse in such a way that
the SDA line is stable low during the high period of the
acknowledge related clock pulse. Of course, setup and
hold times must be taken into account. A master must
signal an end of data to the slave by not generating an
acknowledge bit on the last byte that has been clocked
out of the slave. In this case, the slave must leave the
data line high to enable the master to generate the STOP
condition.
Figure 2 details how data transfer is accomplished on the
two-wire bus. Depending upon the state of the R/W bit,
two types of data transfer are possible:
1. Data transfer from a master transmitter to a slave
receiver. The first byte transmitted by the master
is the slave address. Next follows a number of data
bytes. The slave returns an acknowledge bit after each
received byte.
2. Data transfer from a slave transmitter to a master
receiver. The first byte (the slave address) is transmit-
ted by the master. The slave then returns an acknowl-
edge bit. Next follows a number of data bytes transmit-
ted by the slave to the master. The master returns an
acknowledge bit after all received bytes other than the
last byte. At the end of the last received byte, a ‘not
acknowledge’ is returned.
The master device generates all of the serial clock pulses
and the START and STOP conditions. A transfer is ended
with a STOP condition or with a repeated START condi-
tion. Since a repeated START condition is also the begin-
ning of the next serial transfer, the bus is not released.
The DS1624 can operate in the following two modes:
1. Slave receiver mode: Serial data and clock are
received through SDA and SCL. After each byte is
received an acknowledge bit is transmitted. START
and STOP conditions are recognized as the begin-
ning and end of a serial transfer. Address recognition
is performed by hardware after reception of the slave
address and direction bit.
2. Slave transmitter mode: The first byte is received
and handled as in the slave receiver mode. However,
in this mode the direction bit indicates that the transfer
direction is reversed. Serial data is transmitted on SDA
by the DS1624 while the serial clock is input on SCL.
START and STOP conditions are recognized as the
beginning and end of a serial transfer.
Figure 2. Data Transfer on 2-Wire Serial Bus
SDA
SCL
START
CONDITION
MSB SLAVE ADDRESS
R/W
DIRECTION BIT
ACKNOWLEDGEMENT
SIGNAL FROM RECEIVER
ACKNOWLEDGEMENT
SIGNAL FROM RECEIVER
1 2 6 7 8 9
ACK
REPEATED IF MORE BYTES
ARE TRANSFERRED
1 2 3-8 8 9
STOP CONDITION
OR
REPEATED
START CONDITION
ACK
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Slave Address
A control byte is the first byte received following the
START condition from the master device. The control byte
consists of a four bit control code; for the DS1624, this
is set as 1001 binary for read and write operations. The
next three bits of the control byte are the device select
bits (A2, A1, A0). They are used by the master device to
select which of eight devices are to be accessed. These
bits are in effect the three least significant bits of the slave
address. The last bit of the control byte (R/W) defines
the operation to be performed. When set to a “1”, a read
operation is selected, when set to a “0”, a write operation
is selected. Following the START condition the DS1624
monitors the SDA bus checking the device type identifier
being transmitted. Upon receiving the 1001 code and
appropriate device select bits, the slave device outputs an
acknowledge signal on the SDA line.
Measuring Temperature
Figure 1 shows a block diagram of the DS1624. The
DS1624 measures the temperature using a bandgap-
based temperature sensor. A delta-sigma analog-to-digital
(ADC) converts the temperature to a 12-bit digital value
that is calibrated in °C; for °F applications a lookup table
or conversion routine must be used. Throughout this data
sheet the term “conversion” is used to refer to the entire
temperature measurement and ADC sequence.
The temperature reading is stored as a 16-bit two’s
complement number in the 2-byte temperature register as
shown in Figure 4.
Since data is transmitted over the 2-wire bus MSB first,
temperature data can be written to/read from the DS1624
as either a single byte (with temperature resolution of
1°C) or as 2 bytes, the second byte containing the value
of the four least significant bits of the temperature reading
as shown in Figure 4. Note that the remaining 4 bits of this
byte are set to all zeros.
Figure 3. 2-Wire Serial Communication with DS1624
Figure 4. Temperature Register Format
WRITE TO DS1624
BUS ACTIVITY:
START
1
0
0
1
A2
A1
A0
R/W = 0
ACK
ACK
ACK
CONTROL
BYTE
COMMAND
PROTOCOL
DATA
BYTE
STOP
BUS ACTIVITY
SDA LINE
READ FROM DS1624
START
MASTER
BUS ACTIVITY:
BUS ACTIVITY
SDA LINE
MASTER
1
0
0
1
A2
A1
A0
R/W = 0
1
0
0
1
A2
A1
A0
R/W = 1
ACK
CONTROL
BYTE COMMAND
PROTOCOL
START
CONTROL
BYTE
DATA
BYTE 0
DATA
BYTE 1
ACK
ACK
ACK
NACK
STOP
BIT 15 BIT 14 BIT 13 BIT 12 BIT 11 BIT 10 BIT 9 BIT 8
MS BYTE S 26252423222120
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
LS BYTE 2-1 2-2 2-3 2-4 0000
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Temperature is represented in the DS1624 in terms of a 0.0625°C LSB, yielding the following 12-bit example:
Operation and Control
A configuration/status register is used to determine the method of operation the DS1624 will use in a particular application
as well as indicating the status of the temperature conversion operation.
The configuration register is defined as follows:
where:
DONE = Conversion Done bit, “1” = Conversion complete, “0” = conversion in progress.
1SHOT = One Shot Mode. If 1SHOT is “1,” the DS1624 performs one temperature conversion upon receipt of the Start
Convert T protocol. If 1SHOT is “0,” the DS1624 continuously performs temperature conversions. This bit is nonvolatile
and the DS1624 is shipped with 1SHOT = “0.”
Since the configuration register is implemented in E2, writes to the register require 10ms to complete. After issuing a
command to write to the configuration register, no further accesses to the DS1624 should be made for at least 10ms.
Table 1. Temperature/Data Relationships
TEMP (°C) DIGITAL OUTPUT
(BINARY)
DIGITAL OUTPUT
(HEX)
+125 01111101 00000000 7D00h
+25.0625 00011001 00010000 1910h
+0.5 00000000 10000000 0080h
0 00000000 00000000 0000h
-0.5 11111111 10000000 FF80h
-25.0625 11100110 11110000 E6F0h
-55 11001001 00000000 C900h
MSB LSB
0 0 0 1 1 0 0 1 0 0 0 1 0 0 0 0
= +25.0625°C
CONFIGURATION/STATUS REGISTER
DONE 0 0 0 1 0 1 1SHOT
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Memory
Byte Program Mode
In this mode, the master sends addresses and one data
byte to the DS1624.
Following a START condition, the device code (4-bit), the
slave address (3-bit), and the R/W bit (which is logic-low)
are placed onto the bus by the master. The master then
sends the Access Memory protocol. This indicates to the
addressed DS1624 that a byte with a word address will fol-
low after it has generated an acknowledge bit. Therefore,
the next byte transmitted by the master is the word address
and will be written into the address pointer of the DS1624.
After receiving the acknowledge of the DS1624, the mas-
ter device transmits the data word to be written into the
addressed memory location. The DS1624 acknowledges
again and the master generates a STOP condition. This
initiates the internal programming cycle of the DS1624. A
repeated START condition, instead of a STOP condition,
will abort the programming operation.
During the programming cycle the DS1624 does not
acknowledge any further accesses to the device until the
programming cycle is complete (no longer than 50ms.)
Page Program Mode
To program the DS1624 the master sends addresses and
data to the DS1624, which is the slave. This is done by
supplying a START condition followed by the 4-bit device
code, the 3-bit slave address, and the R/W bit which
is defined as a logic-low for a write. The master then
sends the Access Memory protocol. This indicates to the
addressed slave that a word address will follow. The slave
outputs the acknowledge pulse to the master during the
ninth clock pulse. When the word address is received
by the DS1624 it is placed in the address pointer defin-
ing which memory location is to be written. The DS1624
generates an acknowledge after every 8 bits received and
store them consecutively in an 8-byte RAM until a STOP
condition is detected which initiates the internal program-
ming cycle.
A repeated START condition, instead of a STOP con-
dition, aborts the programming operation. During the
programming cycle the DS1624 does not acknowledge
any further accesses to the device until the programming
cycle is complete (no longer than 50ms).
If more than 8 bytes are transmitted by the master, the
DS1624 rolls over and overwrites the data beginning with
the first received byte. This does not affect erase/write
cycles of the EEPROM array and is accomplished as a
result of only allowing the address register’s bottom 3 bits
to increment while the upper 5 bits remain unchanged.
The DS1624 is capable of 20,000 writes (25,000 erase/
write cycles) before EEPROM wear out can occur.
If the master generates a STOP condition after trans-
mitting the first data word, byte programming mode is
entered.
Read Mode
In this mode, the master is reading data from the DS1624
E2 memory. The master first provides the slave address
to the device with R/W set to “0.” The master then sends
the Access Memory protocol and, after receiving an
acknowledge, then provides the word address, which is
the address of the memory location at which it wishes to
begin reading. Note that while this is a read operation the
address pointer must first be written. During this period
the DS1624 generates acknowledge bits as defined in the
appropriate section.
The master now generates another START condition and
transmits the slave address. This time the R/W bit is set
to “1” to put the DS1624 in read mode. After the DS1624
generates the acknowledge bit it outputs the data from
the addressed location on the SDA pin, increments the
address pointer, and, if it receives an acknowledge from
the master, transmits the next consecutive byte. This
auto-increment sequence is only aborted when the mas-
ter sends a STOP condition instead of an acknowledge.
When the address pointer reaches the end of the 256-
byte memory space (address FFh) it increments from the
end of the memory back to the first location of the memory
(address 00h).
Command Set
Data and control information is read from and written to
the DS1624 in the format shown in Figure 3. To write
to the DS1624, the master issues the slave address of
the DS1624 and the R/W bit is set to 0. After receiving
an acknowledge the bus master provides a command
protocol. After receiving this protocol the DS1624 issues
an acknowledge, and then the master can send data
to the DS1624. If the DS1624 is to be read, the master
must send the command protocol as before then issue a
repeated START condition and the control byte again, this
time with the R/W bit set to 1 to allow reading of the data
from the DS1624. The command set for the DS1624 as
shown in Table 2 is as follows.
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Access Memory [17h]
This command instructs the DS1624 to access its E2
memory. After issuing this command, the next data byte
is the value of the word address to be accessed. See the
Memory section for detailed explanations of the use of
this protocol and data format following it.
Access Cong [ACh]
If R/W is “0”, this command writes to the configuration
register. After issuing this command, the next data byte
is the value to be written into the configuration register. If
R/W is “1,” the next data byte read is the value stored in
the configuration register.
Read Temperature [AAh]
This command reads the last temperature conversion
result. The DS1624 sends 2 bytes in the format described
earlier, which are the contents of this register.
Start Convert T [EEh]
This command begins a temperature conversion. No fur-
ther data is required. In one-shot mode, the temperature
conversion is performed and then the DS1624 remain
sidle. In continuous mode, this command initiates continu-
ous conversions.
Stop Convert T [22h]
This command stops temperature conversion. No further
data is required. This command can be used to halt a
DS1624 in continuous conversion mode. After issuing this
command, the current temperature measurement is com-
pleted, then the DS1624 remains idle until a Start Convert
T is issued to resume continuous operation.
During the programming cycle, the DS1624 does not
acknowledge any further accesses to the device until the
programming cycle is complete (no longer than 50ms).
Note 1: In continuous conversion mode, a Stop Convert T command halta continuous conversion. To restart, the Start Convert T
command must be issued. In one-shot mode, a Start Convert T command must be issued for every temperature reading
desired.
Note 2: Writing to the E2 typically requires 10ms at room temperature. After issuing a write command, no further reads or writes
should be requested for at least 10ms.
Table 2. DS1624 Command Set
INSTRUCTION DESCRIPTION PROTOCOL 2-WIRE BUS DATA AFTER
ISSUING PROTOCOL
TEMPERATURE CONVERSION COMMANDS
Read Temperature Reads last converted temperature value from
temperature register AAh <read 2 bytes data>
Start Convert T Initiates temperature conversion (Note 1) EEh idle
Stop Convert T Halts temperature conversion (Note 1) 22h idle
THERMOSTAT COMMANDS
Access Memory Reads or writes to 256-byte EEPROM memory
(Note 2) 17h <write data>
Access Cong Reads or writes conguration data to
conguration register (Note 2) ACh <write data>
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Memory Function Example
BUS MASTER
MODE
DS1624
MODE
DATA
(MSB FIRST) COMMENTS
{Command protocol for conguration register}
{Start here}
Tx Rx START Bus master initiates a START condition.
Tx Rx <cadr,0> Bus master sends DS1624 address; R/W = 0.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx ACh Bus master sends Access Cong command protocol.
Rx Tx ACK DS1624 generates acknowledge bit (Note 1).
Tx Rx 00h Bus master sets up DS1624 for continuous conversion.
Rx Tx ACK DS1624 generates acknowledge bit (Notes 2, 4).
Tx Rx STOP Bus master initiates the STOP condition.
{Command protocol for Start Convert T}
{Start here}
Tx Rx START Bus master initiates a START condition.
Tx Rx <cadr,0> Bus master sends DS1624 address; R/W = 0.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx EEh Bus master sends Start Convert T command protocol.
Rx Tx ACK DS1624 generates acknowledge bit (Note 1).
Tx Rx STOP Bus master initiates the STOP condition.
{Command protocol for reading the Temperature}
{Start here}
Tx Rx START Bus master initiates a START condition.
Tx Rx <cadr,0> Bus master sends DS1624 address; R/W = 0.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx AAh Bus master sends Read Temp command protocol.
Rx Tx ACK DS1624 generates acknowledge bit (Note 1).
Tx Rx START Bus master initiates a repeated START condition.
Tx Rx <cadr,1> Bus Master sends DS1624 address; R/W = 1.
Rx Tx ACK DS1624 generates acknowledge bit.
Rx Tx <data> DS1624 sends the MSB byte of Temperature.
Tx Rx ACK Bus master generates acknowledge bit.
Rx Tx <data> DS1624 sends the LSB byte of Temperature.
Tx Rx NACK Bus master sends not-acknowledge bit.
Tx Rx STOP Bus master initiates the STOP condition.
{Command protocol for writing to EEPROM}
{Start here}
Tx Rx START Bus master initiates a START condition.
Tx Rx <cadr,0> Bus master sends DS1624 address; R/W = 0.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx 17h Bus master sends Access Memory command protocol.
Rx Tx ACK DS1624 generates acknowledge bit (Note 1).
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Note 1: If this protocol follows a write and the DS1624 does not acknowledge here, restart the protocol at the START here. If it
does acknowledge, continue on.
Note 2: Wait for write to complete (50ms max). If DS1624 does not acknowledge the command protocol immediately following a
configure register or write memory protocol, the DS1624 has not finished writing. Restart the new command protocol until
the DS1624 acknowledges.
Note 3: If n is greater than eight, the last 8 bytes are the only bytes saved in memory. If the starting address is 00 and the incom-
ing data is 00 11 22 33 44 55 66 77 88 99, the result is mem00=88 mem01=99 mem02=22 mem03=33 mem04=44
mem05=55 mem06=66 mem07=77. The data wraps around and overwrites itself.
Note 4: The STOP condition causes the DS1624 to initiate the write to EEPROM sequence. If a START condition comes instead
of the STOP condition, the write is aborted. The data is not saved.
Note 5: For reading, the address is incremented. If the starting address is 04h and 30 bytes of data are read out, 21h is the final
address read.
Memory Function Example (continued)
BUS MASTER
MODE
DS1624
MODE
DATA
(MSB FIRST) COMMENTS
Tx Rx <madr> Bus master sets the starting memory address.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx <data> Bus master sends the rst byte of data.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx <data> Bus master sends the second byte of data.
Rx Tx ACK DS1624 generates acknowledge bit.
. . . . . . . . . . . .
Tx Rx <data> Bus master sends the nth byte of data (Note 3).
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx STOP Bus master initiates the STOP condition (Notes 2, 4)
{Command protocol for reading from EEPROM}
{Start here}
Tx Rx START Bus master initiates a START condition.
Tx Rx <cadr,0> Bus master sends DS1624 address; R/W = 0.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx 17h Bus master sends Access Memory command protocol.
Rx Tx ACK DS1624 generates acknowledge bit (Note 1).
Tx Rx <madr> Bus master sends the starting memory address.
Rx Tx ACK DS1624 generates acknowledge bit.
Tx Rx START Bus master initiates a repeated START condition.
Tx Rx <cadr,1> Bus master sends DS1624 address; R/W = 1.
Rx Tx ACK DS1624 generates acknowledge bit.
Rx Tx <data> DS1624 sends the rst byte of data.
Tx Rx ACK Bus master generates acknowledge bit.
Rx Tx <data> DS1624 sends the second byte of data.
Tx Rx ACK Bus master generates acknowledge bit.
. . . . . . . . . . . .
Rx Tx <data> DS1624 sends the nth byte of data (Note 5).
Tx Rx NACK Bus master sends not-acknowledge bit.
Tx Rx STOP Bus master initiates the STOP condition.
DS1624 Digital Thermometer and Memory
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12
Note: All devices rated for the -55°C to +125°C operating tem-
perature range.
+Denotes a lead(Pb)-free/RoHS-compliant package.
T&R = Tape and reel.
PART TOP MARK PIN-PACKAGE
DS1624+ DS1624 8 PDIP (300 mils)
DS1624S+ DS1624S 8 SO (208 mils)
DS1624S+T&R DS1624S 8 SO (208 mils)
(2000 pieces) PACKAGE
TYPE
PACKAGE
CODE
OUTLINE
NO.
LAND
PATTERN NO.
8 PDIP P8+4 21-0043
8 SO W8+2 21-0262 90-0258
DS1624 Digital Thermometer and Memory
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13
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.
Ordering Information
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 5/12 Updated Ordering Information and Package Information; updated the soldering
information in the Absolute Maximum Ratings section 1, 2, 7, 14, 18
1 12/13
Updated the Features and Description, removed the Overview section; replaced
the OperationMeasuring Temperature section and Figure 4; added the Package
Thermal Characteristics section; updated the DC Electrical Characteristics and
AC Electrical Characteristics tables and related notes
1, 2, 5,
13, 14, 15
2 3/14 Updated the EEPROM Data Retention parameter in the AC Electrical
Characteristics table 14
3 5/14 Updated the Electrical Characteristics 13, 14
4 1/15 Updated Benets and Features sections 1
5 8/15 Updated AC Electrical Characteristics 3
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 specications 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 and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
DS1624 Digital Thermometer and Memory
© 2015 Maxim Integrated Products, Inc.
14
Revision History
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