Original Creation Date: 07/12/95
Last Update Date: 05/06/97
Last Major Revision Date: 07/12/95
MDLM137-K REV 0A0 MICROCIRCUIT DATA SHEET
NEGATIVE ADJUSTABLE VOLTAGE REGULATOR
General Description
The LM137K is an adjustable 3-terminal negative voltage regulator capable of supplying in
excess of -1.5A over an output voltage range of -1.2V to -37V. This regulator is
exceptionally easy to apply, requiring only 2 external resistors to set the output voltage
and 1 output capacitor for frequency compensation. The circuit design has been optimized
for excellent regulation and low thermal transients. Further, the LM137K features internal
current limiting, thermal shutdown, and safe-area compensation, making it virtually
blow-out proof against overloads.
The LM137K serves a wide variety of applications including local on-card regulation,
programmable-output voltage regulation or precision current regulation. The LM137K is an
ideal complement to the LM117K adjustable positive regulator.
NS Part Numbers
LM137K-SMD*
Industry Part Number
LM137
Prime Die
LM137
Controlling Document
7703403YA*
Processing
MIL-STD-883, Method 5004
Quality Conformance Inspection
MIL-STD-883, Method 5005
Subgrp Description Temp ( C)
o
1 Static tests at +25
2 Static tests at +125
3 Static tests at -55
4 Dynamic tests at +25
5 Dynamic tests at +125
6 Dynamic tests at -55
7 Functional tests at +25
8A Functional tests at +125
8B Functional tests at -55
9 Switching tests at +25
10 Switching tests at +125
11 Switching tests at -55
1
MICROCIRCUIT DATA SHEET
MDLM137-K REV 0A0
Features
- Output voltage adjustable from -1.2V to -37V.
- 1.5A output current guaranteed, -55 C to +150 C.
- Line regulation typically 0.01%/V.
- Load regulation typically 0.3%.
- Excellent thermal regulation, 0.002%/W.
- 77 dB ripple rejection.
- Excellent rejection of thermal transients.
- 50 ppm/ C temperature coefficient.
- Temperature-independent current limit.
- Internal thermal overload protection.
- Standard 3-lead transistor package.
- Output is short circuit protected.
2
MICROCIRCUIT DATA SHEET
MDLM137-K REV 0A0
(Absolute Maximum Ratings)
(Note 1)
Power Dissipation
(Note 2) Internally Limited
Input-Output Voltage Differential 40V
Operating Ambient Temperature -55 C to +125 C
Maximum Junction Temperature 150 C
Storage Temperature -65 C to +150 C
Lead Temperature 300 C(Soldering, 10 seconds)
ESD Rating 2K Volts
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. For guaranteed specifications and test
conditions, see the Electrical Characteristics. The guaranteed specifications apply
only for the test conditions listed. Some performance characteristics may degrade
when the device is not operated under the listed test conditions.
Note 2: The maximum power dissipation must be derated at elevated temperatures and is
dictated by Tjmax (maximum junction temperature), ThetaJA (package junction to
ambient thermal resistance), and TA (ambient temperature). The maximum allowable
power dissipation at any temperature is Pdmax = (Tjmax - TA)/ThetaJA or the number
given in the Absolute Maximum Ratings, whichever is lower.
3
MDLM137-K REV 0A0 MICROCIRCUIT DATA SHEET
Electrical Characteristics
DC PARAMETERS
(The following conditions apply to all the following parameters, unless otherwise specified.)
DC: Il = 8mA
SYMBOL PARAMETER CONDITIONS NOTES PIN-
NAME MIN MAX UNIT SUB-
GROUPS
Vref Reference Voltage Vdiff = 3V -1.275 -1.225 V 1
-1.3 -1.2 V 2, 3
Vdiff = 40V -1.275 -1.225 V 1
-1.3 -1.2 V 2, 3
Rline Line Regulation 3V < Vdiff < 40V -9 9 mV 1
3V < Vdiff < 40V -23 23 mV 2, 3
Rload Load Regulation Vdiff = 5V, 8mA < Il < 1.5A -25 25 mV 1, 2,
3
Vdiff = 12V, 8mA < Il < 1.5A -25 25 mV 1
Vdiff = 40V, 8mA < Il < 200mA -25 25 mV 1
Vdiff = 40V, 8mA < Il < 100mA -25 25 mV 2, 3
Vrth Thermal
Regulation Vin = -14.6V, Il = 1.5A, Pd = 20W,
t = 10mS -5 5 mV 1
Iadj Adjustment Pin
Current Vdiff = 3V 100 uA 1, 2,
3
Vdiff = 40V 100 uA 1, 2,
3
Delta
Iadj(line) Adjustment Pin
Current Change 3V < Vdiff < 40V -5 5 uA 1, 2,
3
Delta
Iadj(load) Adjustment Pin
Current Change Vdiff = 5V, 8mA < Il < 1.5A -5 5 uA 1, 2,
3
Ilmin Minimum Load Vdiff = 3V, Vout = -1.4V (forced) 3 mA 1, 2,
3
Vdiff = 10V, Vout = -1.4V (forced) 3 mA 1, 2,
3
Vdiff = 40V, Vout = -1.4V (forced) 5 mA 1, 2,
3
Icl Current Limit Vdiff < 5V 1.5 3.5 A 1, 2,
3
Vdiff < 40V 0.24 1.2 A 1
AC PARAMETERS
(The following conditions apply to all the following parameters, unless otherwise specified.)
AC: Il = 8mA
Rn Ripple Rejection f = 120Hz, Cadj = 10uF, Vout = Vref 1, 2 66 dB 4, 5,
6
Note 1: Group "A" sample only, test at all temps.
Note 2: Bench test, refer to (SG)RPI-3-362.
4
