LM117HV/LM317HV
3-Terminal Adjustable Regulator
General Description
The LM117HV/LM317HV are adjustable 3-terminal positive
voltage regulators capable of supplying in excess of 1.5A
over a 1.2V to 57V output range. They are exceptionally
easy to use and require only two external resistors to set the
output voltage. Further, both line and load regulation are bet-
ter than standard fixed regulators. Also, the LM117HV is
packaged in standard transistor packages which are easily
mounted and handled.
In addition to higher performance than fixed regulators, the
LM117HV series offers full overload protection available only
in IC’s. Included on the chip are current limit, thermal over-
load protection and safe area protection.All overload protec-
tion circuitry remains fully functional even if the adjustment
terminal is disconnected.
Normally, no capacitors are needed unless the device is situ-
ated more than 6 inches from the input filter capacitors in
which case an input bypass is needed. An optional output
capacitor can be added to improve transient response. The
adjustment terminal can be bypassed to achieve very high
ripple rejections ratios which are difficult to achieve with
standard 3-terminal regulators.
Besides replacing fixed regulators, the LM117HV is useful in
a wide variety of other applications. Since the regulator is
“floating” and sees only the input-to-output differential volt-
age, supplies of several hundred volts can be regulated as
long as the maximum input to output differential is not ex-
ceeded, i.e. do not short the output to ground.
Also, it makes an especially simple adjustable switching
regulator, a programmable output regulator, or by connecting
a fixed resistor between the adjustment and output, the
LM117HV can be used as a precision current regulator. Sup-
plies with electronic shutdown can be achieved by clamping
the adjustment terminal to ground which programs the out-
put to 1.2V where most loads draw little current.
The LM117HVK STEEL and LM317HVK STEEL are pack-
aged in standard TO-3 transistor packages, while the
LM117HVH and LM317HVH are packaged in a solid Kovar
base TO-39 transistor package. The LM317HVT uses a TO-
220 plastic package. The LM117HV is rated for operation
from −55˚C to +150˚C, and the LM317HV from 0˚C to
+125˚C.
Features
nAdjustable output down to 1.2V
nGuaranteed 1.5A output current
nLine regulation typically 0.01%/V
nLoad regulation typically 0.1%
nCurrent limit constant with temperature
n100% electrical burn-in
nEliminates the need to stock many voltages
nStandard 3-lead transistor package
n80 dB ripple rejection
nOutput is short-circuit protected
nP
+
Product Enhancement tested
Typical Applications
1.2V-45V Adjustable Regulator
DS009062-1
Full output current not available at high input-output voltages
†Optional—improves transient response. Output capacitors in the range of 1 µF to 1000 µF of aluminum or tantalum electrolytic
are commonly used to provide improved output impedance and rejection of transients.
*Needed if device is more than 6 inches from filter capacitors.
April 2000
LM117HV/LM317HV 3-Terminal Adjustable Regulator
© 2000 National Semiconductor Corporation DS009062 www.national.com
Typical Applications (Continued)
Digitally Selected Outputs
DS009062-2
*Sets maximum VOUT
5V Logic Regulator with
Electronic Shutdown*
DS009062-3
*Min. output ≈1.2V
LM117HV/LM317HV
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Note 4)
Power Dissipation Internally limited
Input—Output Voltage Differential +60V, −0.3V
Operating Junction Temperature Range
LM117HV −55˚C to +150˚C
LM317HV 0˚C to +125˚C
Storage Temperature −65˚C to +150˚C
Lead Temperature (Soldering, 10 sec.) 300˚C
ESD Tolerance (Note 5) 2000V
Electrical Characteristics (Note 2)
Parameter Conditions LM117HV LM317HV Units
Min Typ Max Min Typ Max
Line Regulation T
J
= 25˚C, 3V ≤V
IN
−V
OUT
≤60V 0.01 0.02 0.01 0.04 %/V
(Note 3) I
L
=10mA
Load Regulation T
J
= 25˚C, 10 mA ≤I
OUT
≤I
MAX
0.1 0.3 0.1 0.5 %
Thermal Regulation T
J
= 25˚C, 20 ms Pulse 0.03 0.07 0.04 0.07 %/W
Adjustment Pin Current 50 100 50 100 µA
Adjustment Pin Current Change 10 mA ≤I
L
≤I
MAX
0.2 5 0.2 5 µA
3.0 V ≤(V
IN
−V
OUT
)≤60V
Reference Voltage 3.0 V ≤(V
IN
−V
OUT
)≤60V, (Note 4) 1.20 1.25 1.30 1.20 1.25 1.30 V
10 mA ≤I
OUT
≤I
MAX
,P≤P
MAX
Line Regulation 3.0V ≤(V
IN
−V
OUT
)≤60V, 0.02 0.05 0.02 0.07 %/V
I
L
= 10 mA, (Note 3)
Load Regulation 10 mA ≤I
OUT
≤I
MAX
(Note 3) 0.3 1 0.3 1.5 %
Temperature Stability T
MIN
≤T
J
≤T
MAX
11%
Minimum Load Current (V
IN
−V
OUT
) = 60V 3.5 7 3.5 12 mA
Current Limit (V
IN
−V
OUT
)≤15V
K, T Packages 1.5 2.2 3.5 1.5 2.2 3.7 A
H Package 0.5 0.8 1.8 0.5 0.8 1.9 A
(V
IN
−V
OUT
)≤60V
K, T Packages 0.3 0.3 A
H Package 0.03 0.03 A
RMS Output Noise, % of V
OUT
T
J
= 25˚C, 10 Hz ≤f≤10 kHz 0.003 0.003 %
Ripple Rejection Ratio V
OUT
= 10V, f = 120 Hz 65 65 dB
C
ADJ
=10µF 6680 6680 dB
Long-Term Stability T
J
= 125˚C 0.3 1 0.3 1 %
Thermal Resistance, H Package 12 15 12 15 ˚C/W
Junction to Case T Package 4 5 ˚C/W
K Package 2.3 3 2.3 3 ˚C/W
Thermal Resistance, H Package 140 140 ˚C/W
Junction to Ambient T Package 50 ˚C/W
(no heat sink) K Package 35 35 ˚C/W
Note 1: “Absolute Maximum Ratings” indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: Unless otherwise specified, these specifications apply: −55˚C ≤TJ≤+150˚C for the LM117HV, and 0˚C ≤TJ≤+125˚C for the LM317HV; VIN −V
OUT =5V
and IOUT = 0.1Afor the TO-39 package and IOUT = 0.5Afor the TO-3 and TO-220 packages. Although power dissipation is internally limited, these specifications are
applicable for power dissipations of 2W for the TO-39 and 20W for the TO-3 and TO-220. IMAX is 1.5A for the TO-3 and TO-220 and 0.5A for the TO-39 package.
Note 3: Regulation is measured at constant junction temperature. Changes in output voltage due to heating effects must be taken into account separately. Pulse test-
ing with low duty cycle is used.
Note 4: Refer to RETS117HVH for LM117HVH or RETS117HVK for LM117HVK military specificatioins.
Note 5: Human body model, 1.5 kΩin series with 100 pF.
LM117HV/LM317HV
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Typical Performance Characteristics Output capacitor = 0 µF unless otherwise noted.
Load Regulation
DS009062-32
Current Limit
DS009062-33
Adjustment Current
DS009062-34
Dropout Voltage
DS009062-35
Temperature Stability
DS009062-36
Minimum Operating Current
DS009062-37
Ripple Rejection
DS009062-38
Ripple Rejection
DS009062-39
Ripple Rejection
DS009062-40
Output Impedance
DS009062-41
Line Transient Response
DS009062-42
Load Transient Response
DS009062-43
LM117HV/LM317HV
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Application Hints
In operation, the LM117HV develops a nominal 1.25V refer-
ence voltage, V
REF
, between the output and adjustment ter-
minal. The reference voltage is impressed across program
resistor R1 and, since the voltage is constant, a constant
current I
1
then flows through the output set resistor R2, giv-
ing an output voltage of
Since the 100 µAcurrent from the adjustment terminal repre-
sents an error term, the LM117HV was designed to minimize
I
ADJ
and make it very constant with line and load changes.
To do this, all quiescent operating current is returned to the
output establishing a minimum load current requirement. If
there is insufficient load on the output, the output will rise.
External Capacitors
An input bypass capacitor is recommended. A 0.1 µF disc or
1 µF solid tantalum on the input is suitable input bypassing
for almost all applications. The device is more sensitive to
the absence of input bypassing when adjustment or output
capacitors are used but the above values will eliminate the
possiblity of problems.
The adjustment terminal can be bypassed to ground on the
LM117HV to improve ripple rejection. This bypass capacitor
prevents ripple from being amplified as the output voltage is
increased. With a 10 µF bypass capacitor 80 dB ripple rejec-
tion is obtainable at any output level. Increases over 10 µF
do not appreciably improve the ripple rejection at frequen-
cies above 120 Hz. If the bypass capacitor is used, it is
sometimes necessary to include protection diodes to prevent
the capacitor from discharging through internal low current
paths and damaging the device.
In general, the best type of capacitors to use are solid tanta-
lum. Solid tantalum capacitors have low impedance even at
high frequencies. Depending upon capacitor construction, it
takes about 25 µF in aluminum electrolytic to equal 1 µF
solid tantalum at high frequencies. Ceramic capacitors are
also good at high frequencies; but some types have a large
decrease in capacitance at frequencies around 0.5 MHz. For
this reason, 0.01 µF disc may seem to work better than a 0.1
µF disc as a bypass.
Although the LM117HV is stable with no output capacitors,
like any feedback circuit, certain values of external capaci-
tance can cause excessive ringing. This occurs with values
between 500 pF and 5000 pF.A1 µF solid tantalum (or 25 µF
aluminum electrolytic) on the output swamps this effect and
insures stability. Any increase of load capacitance larger
than 10 µF will merely improve the loop stability and output
impedance.
Load Regulation
The LM117HV is capable of providing extremely good load
regulation but a few precautions are needed to obtain maxi-
mum performance. The current set resistor connected be-
tween the adjustment terminal and the output terminal (usu-
ally 240Ω) should be tied directly to the output of the
regulator rather than near the load. This eliminates line
drops from appearing effectively in series with the reference
and degrading regulation. For example, a 15V regulator with
0.05Ωresistance between the regulator and load will have a
load regulation due to line resistance of 0.05ΩxI
L
. If the set
resistor is connected near the load the effective line resis-
tance will be 0.05Ω(1 + R2/R1) or in this case, 11.5 times
worse.
Figure 2
shows the effect of resistance between the regula-
tor and 240Ωset resistor.
With the TO-3 package, it is easy to minimize the resistance
from the case to the set resistor, by using two separate leads
to the case. However, with the TO-5 package, care should be
taken to minimize the wire length of the output lead. The
ground of R2 can be returned near the ground of the load to
provide remote ground sensing and improve load regulation.
Protection Diodes
When external capacitors are used with
any
IC regulator it is
sometimes necessary to add protection diodes to prevent
the capacitors from discharging through low current points
into the regulator. Most 10 µF capacitors have low enough
internal series resistance to deliver 20A spikes when
shorted. Although the surge is short, there is enough energy
to damage parts of the IC.
When an output capacitor is connected to a regulator and
the input is shorted, the output capacitor will discharge into
the output of the regulator. The discharge current depends
on the value of the capacitor, the output voltage of the regu-
lator, and the rate of decrease of V
IN
. In the LM117HV, this
discharge path is through a large junction that is able to sus-
tain 15A surge with no problem. This is not true of other
types of positive regulators. For output capacitors of 25 µF or
less, there is no need to use diodes.
The bypass capacitor on the adjustment terminal can dis-
charge through a low current junction. Discharge occurs
when
either
the input or output is shorted. Internal to the
LM117HV is a 50Ωresistor which limits the peak discharge
current. No protection is needed for output voltages of 25V
DS009062-5
FIGURE 1.
DS009062-6
FIGURE 2. Regulator with Line
Resistance in Output Lead
LM117HV/LM317HV
www.national.com5
Application Hints (Continued)
or less and 10 µF capacitance.
Figure 3
shows an LM117HV
with protection diodes included for use with outputs greater
than 25V and high values of output capacitance.
Current Limit
Internal current limit will be activated whenever the output
current exceeds the limit indicated in the Typical Perfor-
mance Characteristics. However, if during a short circuit con-
dition the regulator’s differential voltage exceeds the Abso-
lute Maximum Rating of 60V (e.g. V
IN
≥60V, V
OUT
= 0V),
internal junctions in the regulator may break down and the
device may be damaged or fail. Failure modes range from an
apparent open or short from input to output of the regulator,
to a destroyed package (most common with the TO-220
package). To protect the regulator, the user is advised to be
aware of voltages that may be applied to the regulator during
fault conditions, and to avoid violating the Absolute Maxi-
mum Ratings. Note: D1 protects against C1
D2 protects against C2
Schematic Diagram
Typical Applications
DS009062-7
FIGURE 3. Regulator with Protection Diodes
DS009062-8
Slow Turn-On 15V Regulator
DS009062-9
Adjustable Regulator with Improved
Ripple Rejection
DS009062-10
†Solid tantalum
*Discharges C1 if output is shorted to ground
LM117HV/LM317HV
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Typical Applications (Continued)
High Stability 10V Regulator
DS009062-11
High Current Adjustable Regulator
DS009062-12
†Solid tantalum
*Minimum load current = 30 mA
‡Optional—improves ripple rejection
0 to 30V Regulator
DS009062-13
Full output current not available at high input-output voltages
Power Follower
DS009062-14
LM117HV/LM317HV
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Typical Applications (Continued)
5A Constant Voltage/Constant Current Regulator
DS009062-15
†Solid tantalum
*Lights in constant current mode
1A Current Regulator
DS009062-16
1.2V–20V Regulator with
Minimum Program Current
DS009062-17
*Minimum load current ≈4mA
LM117HV/LM317HV
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Typical Applications (Continued)
High Gain Amplifier
DS009062-18
Low Cost 3A Switching Regulator
DS009062-19
†Solid tantalum
*Core—Arnold A-254168-2 60 turns
4A Switching Regulator with Overload Protection
DS009062-20
†Solid tantalum
*Core—Arnold A-254168-2 60 turns
LM117HV/LM317HV
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Typical Applications (Continued)
Precision Current Limiter
DS009062-21
* 0.8Ω≤R1 ≤120Ω
Tracking Preregulator
DS009062-22
Adjustable Multiple On-Card Regulators
with Single Control*
DS009062-23
*All outputs within ±100 mV
†Minimum load—10 mA
AC Voltage Regulator
DS009062-24
12V Battery Charger
DS009062-25
Use of RSallows low charging rates with fully charged battery.
**The 1000 µF is recommended to filter out input transients
LM117HV/LM317HV
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Typical Applications (Continued)
50 mA Constant Current Battery Charger
DS009062-26
Adjustable 4A Regulator
DS009062-27
Current Limited 6V Charger
DS009062-28
*Sets peak current (0.6A for 1Ω)
**The 1000 µF is recommended to filter out input transients
LM117HV/LM317HV
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Connection Diagrams (See Physical Dimension section for further information)
(TO-3)
Metal Can Package
DS009062-29
Case is Output
Bottom View
Order Number LM117HVKSTL/883
See NS Package Number K02C
Order Number LM317HVK STEEL
See NS Package Number K02A
(TO-39)
Metal Can Package
DS009062-30
Case is Output
Bottom View
Order Number LM117HVH,
LM117HVH/883
or LM317HVH
See NS Package Number H03A
(TO-220)
Plastic Package
DS009062-31
Front View
Order Number LM317HVT
See NS Package Number T03B
LM117HV/LM317HV
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Physical Dimensions inches (millimeters) unless otherwise noted
Order Number LM117HVH, LM117HVH/883, or LM317HVH
NS Package Number H03A
Metal Can Package (K)
Order Number LM317HVK STEEL
NS Package Number K02A
LM117HV/LM317HV
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
Metal Can Package (K)
Mil-Aero Product
Order Number LM117HVKSTL/883
NS Package Number K02C
Order Number LM317HVT
NS Package Number T03B
LM117HV/LM317HV
www.national.com 14
Notes
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COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
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into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a
significant injury to the user.
2. A critical component is any component of a life
support device or system whose failure to perform
can be reasonably expected to cause the failure of
the life support device or system, or to affect its
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LM117HV/LM317HV 3-Terminal Adjustable Regulator
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
