1
137afb
LT137A/LM137
LT337A/LM337
TYPICAL APPLICATION
FEATURES
APPLICATIONS
DESCRIPTION
Negative Adjustable
Regulator
The LT
®
137A/LT337A negative adjustable regulators will
deliver up to 1.5A output current over an output voltage
range of –1.2V to –37V. Linear Technology has made
signifi cant improvements in these regulators compared to
previous devices, such as better line and load regulation,
and a maximum output voltage error of 1%.
Every effort has been made to make these devices easy
to use and diffi cult to damage. Internal current and power
limiting coupled with true thermal limiting prevents device
damage due to overloads or shorts, even if the regulator
is not fastened to a heat sink.
Maximum reliability is attained with Linear Technology’s
advanced processing techniques combined with a 100%
burn-in in the thermal limit mode. This assures that all
device protection circuits are working and eliminates fi eld
failures experienced with other regulators that receive only
standard electrical testing.
Negative Regulator
n Guaranteed 1% Initial Voltage Tolerance
n Guaranteed 0.01%/V Line Regulation
n Guaranteed 0.5% Load Regulation
n Guaranteed 0.02%/W Thermal Regulation
n 100% Burn-in in Thermal Limit
n Adjustable Power Supplies
n System Power Supplies
n Precision Voltage/Current Regulators
n On-Card Regulators
L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
Output Voltage Error
LT137A
ADJ
VIN
–VIN
R2*
*R2 = R1
VOUT –VOUT = 1.25V 1 + R2
R1
137A TA01
+
R1
121Ω
C3
1μF
SOLID
TANTALUM
+C2
5μF
SOLID
TANTALUM
– 1
|
VOUT
|
1.25V
OUTPUT VOLTAGE (V)
12 468 2040
OUTPUT VOLTAGE ERROR (%)
12
11
10
9
8
7
6
5
4
3
2
1
0
10 100
137A TA01b
LM337
LT337A
1% RESISTORS
2% RESISTORS
LT137A/LM137
LT337A/LM337
2
137afb
PRECONDITIONING ABSOLUTE MAXIMUM RATINGS
Power Dissipation .......................…….Internally Limited
Input to Output Voltage Differential ..................…….40V
Operating Junction Temperature Range
LT137A/LM137 .................................. –55°C to 150°C
LT337A/LM337 ...................................... 0°C to 125°C
Storage Temperature Range
LT137A/LM137 .................................. –65°C to 150°C
LT337A/LM337 .................................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec.) ................. 300°C
(Note 1)
2
1
VOUT
CASE
IS VIN
ADJ
K PACKAGE
2-LEAD TO-3 METAL CAN
BOTTOM VIEW
θJA = 35°C/W, θJC = 3°C/W
OBSOLETE PACKAGE
Consider the M and T Packages for Alternate Source
BOTTOM VIEW
CASE IS INPUT
1
2
3
VOUT
VIN
ADJ
H PACKAGE
3-LEAD TO-39 METAL CAN
θJA = 150°C/W, θJC = 15°C/W
OBSOLETE PACKAGE
Consider the M and T Packages for Alternate Source
M PACKAGE
3-LEAD PLASTIC DD
FRONT VIEW
TAB
IS
INPUT
VOUT
VIN
ADJ
3
2
1
θJA = 30°C/W, θJC = 3°C/W
TAB IS
INPUT
T PACKAGE
3-LEAD PLASTIC TO-220
VOUT
VIN
ADJ
FRONT VIEW
3
2
1
θJA = 50°C/W, θJC = 4°C/W
PIN CONFIGURATION
ORDER INFORMATION
100% Thermal Limit Burn-In
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT337AM#PBF LT337AM#TRPBF LT337AM 3-Lead Plastic DD 0°C to 125°C
LT337AT#PBF LT337AT#TRPBF LT337AT 3-Lead Plastic TO-220 0°C to 125°C
LM337T#PBF LM337T#TRPBF LM337T 3-Lead Plastic TO-220 0°C to 125°C
LEAD BASED FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT337AM LT337AM#TR LT337AM 3-Lead Plastic DD 0°C to 125°C
LT337AT LT337AT#TR LT337AT 3-Lead Plastic TO-220 0°C to 125°C
3
137afb
LT137A/LM137
LT337A/LM337
ORDER INFORMATION
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. (Notes 2, 3)
SYMBOL PARAMETER CONDITIONS
LT137A LM137
UNITSMIN TYP MAX MIN TYP MAX
VREF Reference Voltage
|
VIN – VOUT
|
= 5V, IOUT = 10mA, Tj = 25°C –1.238 –1.250 –1.262 –1.225 –1.250 –1.275 V
3V ≤
|
VIN – VOUT
|
≤ 40V
10mA ≤ IOUT ≤ IMAX, P ≤ PMAX
l–1.220 –1.250 –1.280 –1.200 –1.250 –1.300 V
ΔVOUT
ΔIOUT
Load Regulation 10mA ≤ IOUT ≤ IMAX, (Note 4)
T
j = 25°C,
|
VOUT
|
≤ 5V
T
j = 25°C,
|
VOUT
|
≥ 5V
|
VOUT
|
≤ 5V
|
VOUT
|
≥ 5V
l
l
5
0.1
10
0.2
25
0.5
50
1
15
0.3
20
0.3
25
0.5
50
1
mV
%
mV
%
ΔVOUT
ΔVIN
Line Regulation 3V ≤
|
VIN – VOUT
|
≤ 40V (Note 4)
T
j = 25°C
l
0.005
0.01
0.01
0.03
0.01
0.02
0.02
0.05
%/V
%/V
Ripple Rejection VOUT = –10V, f = 120Hz
C
ADJ = 0
C
ADJ = 10μF l
60
70
66
80 66
60
77
dB
dB
Thermal Regulation Tj = 25°C, 10ms Pulse 0.002 0.02 0.002 0.02 %/W
IADJ Adjust Pin Current l65 100 65 100 μA
ΔIADJ Adjust Pin Current Change 10mA ≤ IOUT ≤ IMAX
3V ≤
|
VIN – VOUT
|
≤ 40V
l
l
0.2
1
2
5
0.5
2
5
5
μA
μA
Minimum Load Current
|
VIN – VOUT
|
≤ 40V
|
VIN – VOUT
|
≤ 10V
l
l
2.5
1.2
5
3
2.5
1.2
5
3
mA
mA
ISC Current Limit
|
VIN – VOUT
|
≤ 15V,
K and T Package (Note 7)
H Package
|
VIN – VOUT
|
= 40V,
K and T Package
Tj = 25°C H Package
l
l
1.5
0.5
0.24
0.15
2.2
0.8
0.4
0.25
1.5
0.5
0.24
0.15
2.2
0.8
0.4
0.25
A
A
A
A
ΔVOUT
ΔTemp
Temperature Stability of
Output Voltage (Note 6)
TMIN ≤ T ≤ TMAX l0.6 1.5 0.6 %
ΔVOUT
ΔTime
Long Term Stability TA = 125°C, 1000 Hours 0.3 1 0.3 1 %
enRMS Output Noise
(% of VOUT)
TA = 25°C, 10Hz ≤ f ≤ 10kHz 0.003 0.003 %
θJC Thermal Resistance Junction
to Case
H Package
K Package
12
2.3
15
3
12
2.3
15
3
°C/W
°C/W
ELECTRICAL CHARACTERISTICS
LEAD BASED FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION TEMPERATURE RANGE
LM337T LM337T#TR LM337T 3-Lead Plastic TO-220 0°C to 125°C
Consult LTC Marketing for parts specifi ed with wider operating temperature ranges. *The temperature grade is identifi ed by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based fi nish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifi cations, go to: http://www.linear.com/tapeandreel/
LT137A/LM137
LT337A/LM337
4
137afb
ELECTRICAL CHARACTERISTICS
The l denotes the specifi cations which apply over the full operating
temperature range, otherwise specifi cations are at TA = 25°C. (Notes 2, 3)
SYMBOL PARAMETER CONDITIONS
LT337A LM337
UNITSMIN TYP MAX MIN TYP MAX
VREF Reference Voltage
|
VIN – VOUT
|
= 5V, IOUT = 10mA, Tj = 25°C –1.238 –1.250 –1.262 –1.213 –1.250 –1.287 V
3V ≤
|
VIN – VOUT
|
≤ 40V
10mA ≤ IOUT ≤ IMAX, P ≤ PMAX
l–1.220 –1.250 –1.280 –1.200 –1.250 –1.300 V
ΔVOUT
ΔIOUT
Load Regulation 10mA ≤ IOUT ≤ IMAX, (Notes 4 and 5)
T
j = 25°C,
|
VOUT
|
≤ 5V
T
j = 25°C,
|
VOUT
|
≥ 5V
|
VOUT
|
≤ 5V
|
VOUT
|
≥ 5V
l
l
5
0.1
10
0.2
25
0.5
50
1
15
0.3
20
0.3
50
1
70
1.5
mV
%
mV
%
ΔVOUT
ΔVIN
Line Regulation 3V ≤
|
VIN – VOUT
|
≤ 40V (Note 4)
T
j = 25°C
l
0.005
0.01
0.01
0.03
0.01
0.02
0.04
0.07
%/V
%/V
Ripple Rejection VOUT = –10V, f = 120Hz
C
ADJ = 0
C
ADJ = 10μF l
60
70
66
80 66
60
77
dB
dB
Thermal Regulation Tj = 25°C, 10ms Pulse 0.002 0.02 0.003 0.04 %/W
IADJ Adjust Pin Current l65 100 65 100 μA
ΔIADJ Adjust Pin Current Change 10mA ≤ IOUT ≤ IMAX
3V ≤
|
VIN – VOUT
|
≤ 40V
l
l
0.2
1
2
5
0.5
2
5
5
μA
μA
Minimum Load Current
|
VIN – VOUT
|
≤ 40V
|
VIN – VOUT
|
≤ 10V
l
l
2.5
1.2
5
3
2.5
1
10
6
mA
mA
ISC Current Limit
|
VIN – VOUT
|
≤ 15V,
K, M and T Package
H Package
|
VIN – VOUT
|
= 40V,
K, M and T Package
Tj = 25°C H Package
l
l
1.5
0.5
0.24
0.15
2.2
0.8
0.5
0.25
1.5
0.5
0.15
0.1
2.2
0.8
0.4
0.17
A
A
A
A
ΔVOUT
ΔTemp
Temperature Stability of
Output Voltage (Note 6)
l0.6 1.5 0.6 %
ΔVOUT
ΔTime
Long Term Stability TA = 125°C, 1000 Hours 0.3 1 0.3 1 %
enRMS Output Noise
(% of VOUT)
TA = 25°C, 10Hz ≤ f ≤ 10kHz 0.003 0.003 %
θJC Thermal Resistance Junction
to Case
H Package
K Package
M and T Package
12
2.3
3
15
3
5
12
2.3
3
15
3
5
°C/W
°C/W
°C/W
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The shaded electrical specifi cations indicate those parameters
which have been improved or guaranteed test limits provided for the fi rst
time.
Note 3: Unless otherwise indicated, these specifi cations apply:
|
VIN
– VOUT
|
= 5V; and IOUT = 0.1A for the H package, IOUT = 0.5A for the K, M,
and T packages. Power dissipation is internally limited. However, these
specifi cations apply for power dissipation up to 2W for the H package and
20W for the K and T packages. IMAX = 1.5A for the K, M, and T packages,
and 0.2A for the H package.
Note 4: Testing is done using a pulsed low duty cycle technique. See
thermal regulation specifi cations for output changes due to heating effects.
Load regulation is measured on the output pin at a point 1/8" below the
base of the K and H package and at the junction of the wide and narrow
portion of the lead on the M and T package.
Note 5: Load regulation for the LT337AT is the same as for LM337T.
Note 6: Guaranteed on LT137A and LT337A, but not 100% tested in
production.
Note 7: ISC is tested at the ambient temperatures of 25°C and –55°C. ISC
cannot be tested at the maximum ambient temperature of 150°C due to the
high power level required. ISC specifi cation at 150°C ambient is guaranteed
by characterization and correlation to 25°C testing.
5
137afb
LT137A/LM137
LT337A/LM337
OUTPUT CURRENT (A)
0.01
RIPPLE REJECTION (dB)
100
80
60
40
20
0
137A G06
0.1 1 10
CADJ = 10μF
VIN = –15V
VOUT = –10V
f = 120Hz
Tj = 25°C
CADJ = 0
FREQUENCY (Hz)
10 100
RIPPLE REJECTION (dB)
100
80
60
40
20
0
137A G05
1k 10k 100k 1M
CADJ = 10μF
VIN = –15V
VOUT = –10V
IL = 500mA
Tj = 25°C
CADJ = 0
OUTPUT VOLTAGE (V)
0
RIPPLE REJECTION (dB)
100
80
60
40
20
0
137A G04
–10 –20 –30 –40
CADJ = –10μF
|VIN – VOUT| = 5V
IL = 500mA
f = 120Hz
Tj = 25°C
CADJ = 0
TEMPERATURE (°C)
–75 75–25
REFERENCE VOLTAGE (V)
1.270
1.260
1.250
1.240
1.230
137A G02
–50 25 500 150100 125
OUTPUT CURRENT (A)
0
INPUT-OUTPUT DIFFERENTIAL
3.0
2.6
2.2
1.8
1.4
1.0 1.6
137A G01
0.4 0.8 1.2 2.0
Tj = –55°C
Tj = 25°C
Tj = 150°C
TYPICAL PERFORMANCE CHARACTERISTICS
Dropout Voltage Temperature Stability Minimum Load Current
Ripple Rejection Ripple Rejection Ripple Rejection
INPUT-OUTPUT DIFFERENTIAL (V)
0
CURRENT (mA)
1.8
1.6
1.2
1.4
0.8
0.6
0.2
0.4
0
1.0
137A G03
40302010
Tj = –55°C
Tj = 150°C
Tj = 25°C
LT137A/LM137
LT337A/LM337
6
137afb
TEMPERATURE (°C)
–75 75–25
ADJUSTMENT CURRENT (μA)
80
75
70
65
60
55
50
137A G12
–50 25 500 150100 125
OUTPUT CURRENT (A)
*THE LT137A/LT337A HAS LOAD REGULATION
COMPENSATION WHICH MAKES THE TYPICAL
UNIT READ CLOSE TO ZERO. THIS BAND
REPRESENTS THE TYPICAL PRODUCTION
SPREAD.
0
OUTPUT VOLTAGE DEVIATION (%)
1.6
137A G10
0.4 0.8 1.2 2.0
0.4
0.2
0
–0.2
–0.4
INPUT-OUTPUT DIFFERENTIAL (V)
0
OUTPUT CURRENT (A)
3
2
1
0
137A G11
40302010
H
PACKAGE
M, T AND K
PACKAGES
Tj = –55°C
Tj = 25°C
Tj = 150°C
TIME (μs)
10
OUTPUT VOLTAGE
DEVIATION (V)
INPUT VOLTAGE
CHANGE (V)
0.8
0.6
0.4
0.2
–0.4
–0.5
–0.2
0
0
–1.0
137A G08
03020 40
CADJ = 10μF
VOUT = –10V
IL = 50mA
CL = 1μF
Tj = 25°C
CADJ = 0
FREQUENCY (Hz)
10 100
OUTPUT IMPEDANCE (Ω)
101
100
10–1
10–2
10–3
137A G07
1k 10k 100k 1M
CADJ = 10μF
VIN = –15V
VOUT = –10V
IL = 500mA
CL = 1μF
Tj = 25°C
CADJ = 0
TYPICAL PERFORMANCE CHARACTERISTICS
Output Impedance Line Transient Response Load Transient Response
Load Regulation* Current Limit Adjustment Current
TIME (μs)
10
OUTPUT VOLTAGE
DEVIATION (V)LOAD CURRENT (A)
0.6
0.4
0.2
–0.6
–0.4
–0.5
–0.2
0
0
–1.5
–1.0
137A G09
03020 40
CADJ = 0
VIN = –15V
VOUT = –10V
INL = 50mA
CL = 1μF
Tj = 25°C
CADJ = 10μF
7
137afb
LT137A/LM137
LT337A/LM337
Output Voltage
The output voltage is determined by two external resis-
tors, R1 and R2 (see Figure 1). The exact formula for the
output voltage is:
VV R
RIR
OUT REF ADJ
=+
⎛
⎝
⎜⎞
⎠
⎟+
()
12
12
Where: VREF = Reference Voltage, IADJ = Adjustment Pin
Current. In most applications, the second term is small
enough to be ignored, typically about 0.5% of VOUT
. In
more critical applications, the exact formula should be
used, with IADJ equal to 65μA. Solving for R2 yields:
RVV
V
RI
OUT REF
REF ADJ
2
1
=
+
–
Smaller values of R1 and R2 will reduce the infl uence
of IADJ on the output voltage, but the no-load current
drain on the regulator will be increased. Typical values
for R1 are between 100Ω and 300Ω, giving 12.5mA and
4.2mA no-load current respectively. There is an additional
consideration in selecting R1, the minimum load current
specifi cation of the regulator. The operating current of the
LT137A fl ows from input to output. If this current is not
absorbed by the load, the output of the regulator will rise
above the regulated value. The current drawn by R1 and
R2 is normally high enough to absorb the current, but
care must be taken in no-load situations where R1 and
R2 have high values.
The maximum value for the operating current, which must
be absorbed, is 5mA for the LT137A. If input-output volt-
age differential is less than 10V, the operating current that
must be absorbed drops to 3mA.
APPLICATIONS INFORMATION
EXAMPLES:
1. A precision 10V regulator to supply up to 1A load
current.
a. Select R1 = 100Ω to minimize effect of IADJ
b. Calculate R2 =
VV
V
RI
VV
Vμ
OUT REF
REF ADJ
––.
.
1
10 1 25
125
100 65
+
=
+
ΩAA
=696 4. Ω
Use R2 = 698Ω
2. A 15V regulator to run off batteries and supply
50mA. VIN MAX = 25V
a. To minimize battery drain, select R1 as high as
possible
RV
mA
1125
3417==
.ΩΩ,use402 ,1%
b. The high value for R1 will exaggerate the error due
to IADJ, so the exact formula to calculate R2 should
be used.
RVV
V
RI
VV
V
OUT REF
REF ADJ
2
1
15 1 25
125
402
=
+
=
+
––.
.
Ω665
4331
μA
=Ω
Use R2 = 4320Ω
Capacitors and Protection Diodes
An output capacitor, C3, is required to provide proper fre-
quency compensation of the regulator feedback loop. A 1μF
or larger solid tantalum capacitor is generally suffi cient for
this purpose if the 1MHz impedance of the capacitor is 2Ω
or less. High Q capacitors, such as Mylar, are not recom-
mended because they tend to reduce the phase margin at
light load currents. Aluminum electrolytic capacitors may
also be used, but the minimum value should be 10μF to
ensure a low impedance at 1MHz. The output capacitor
should be located within a few inches of the regulator to
keep lead impedance to a minimum. The following caution
should be noted: if the output voltage is greater than 6V
and an output capacitor greater than 20μF has been used,
it is possible to damage the regulator if the input voltage
Figure 1
LT137A
ADJ
IADJ
VIN
–VIN
R2
VOUT
VREF
–VOUT
137A F01
+
R1
C3
1μF
+C2
5μF
+C1
10μF
LT137A/LM137
LT337A/LM337
8
137afb
becomes shorted, due to the output capacitor discharging
into the regulator. This can be prevented by using the diode
D1 (see Figure 2) between the input and the output.
The input capacitor, C2, is only required if the regulator is
more than 4 inches from the raw supply fi lter capacitor.
Bypassing the Adjustment Pin
The adjustment pin of the LT137A may be bypassed with a
capacitor to ground, C1, to reduce output ripple, noise, and
impedance. These parameters scale directly with output
voltage if the adjustment pin is not bypassed. A bypass
capacitor reduces ripple, noise, and impedance to that of
a 1.25V regulator. In a 15V regulator, for example, these
parameters are improved by 15V/1.25V = 12 to 1. This
improvement holds only for those frequencies where the
impedance of the bypass capacitor is less than R1. Ten
microfarads is generally suffi cient for 60Hz power line
applications where the ripple frequency is 120Hz since
XC = 130Ω. The capacitor should have a voltage rating at
least as high as the output voltage of the regulator. Values
larger than 10μF may be used, but if the output is larger
than 25V, a diode, D2, should be added between the output
and adjustment pins (see Figure 2).
Proper Connection of Divider Resistors
The LT137A has an excellent load regulation specifi cation
of 0.5% and is measured at a point 1/8" from the bottom
of the package. To prevent degradation of load regulation,
the resistors which set output voltage, R1 and R2, must be
connected as shown in Figure 3. Note that the positive side
of the load has a true force and sense (Kelvin) connection,
but the negative side of the load does not.
R1 should be connected directly to the output lead of the
regulator, as close as possible to the specifi ed point 1/8"
from the case. R2 should be connected to the positive
side of the load separately from the positive (ground)
connection to the raw supply. With this arrangement, load
regulation is degraded only by the resistance between the
regulator output pin and the load. If R1 is connected to
the load, regulation will be degraded.
LT137A
ADJ
VIN
–VIN
R2
*D1 PROTECTS THE REGULATOR FROM INPUT SHORTS TO GROUND. IT IS
REQUIRED ONLY WHEN C3 IS LARGER THAN 20μF AND VOUT IS LARGER THAN 6V.
**D2 PROTECTS THE ADJUST PIN OF THE REGULATOR FROM OUTPUT SHORTS
IF C2 IS LARGER THAN 10μF AND VOUT IS LARGER THAN –25V.
D1*
1N4002
D2**
1N4002
VOUT –VOUT
137A F02
+
R1
C3
+
C1
+
C2
Figure 2
LT137A
ADJ
VIN
–VIN
R2
CONNECT R1
DIRECTLY TO
REGULATOR PIN
LEAD RESISTANCE HERE
DEGRADES LOAD REGULATION.
MINIMIZE THE LENGTH OF
THIS LEAD.
LEAD RESISTANCE HERE DOES
NOT AFFECT LOAD REGULATION
VOUT 137A F03
R1
LOAD
Figure 3
APPLICATIONS INFORMATION
9
137afb
LT137A/LM137
LT337A/LM337
TYPICAL APPLICATIONS
A high stability regulator is illustrated in the application
circuit shown to the right. The output stability, load regula-
tion, line regulation, thermal regulation, temperature drift,
long term drift, and noise can be improved by a factor of
6.6 over the standard regulator confi guration. This assumes
a zener whose drift and noise is considerably better than
the regulator itself. The LM329B has 20ppm/°C maximum
drift and about 10 times lower noise than the regulator.
In the application shown below, regulators #2 to “N” will
track regulator #1 to within ±24mV initially, and to ±60mV
over all load, line, and temperature conditions. If any
regulator output is shorted to ground, all other outputs will
drop to approximately ≈ –2V. Load regulation of regula-
tors 2 to “N” will be improved by VOUT/1.25V compared
to a standard regulator, so regulator #1 should be the one
which has the lowest load current.
Multiple Tracking Regulators
High Stability Regulator
Dual Tracking Supply ±1.25V to ±20V
Current Regulator
LT137A
ADJ
VIN
–VIN
R2*
7V
LM329B
VOUT –VOUT
137A TA03
R1
1k
1%
R3
1.5k
1%
+1μF
SOLID
TANTALUM
*R2 = – 908Ω
|
VOUT
|
9.08 • 10–3
LT337A
ADJ
VIN
(–) VOUT (+)
137A TA05
RSI
+C1
1μF
SOLID TANTALUM
I = 65μA +
(0.8Ω < RS < 250Ω)
1.25V
RS
LT337A
ADJ
VIN
–VIN
R3
5k
*SOLID TANTALUM
**R1 OR R5 MAY BE TRIMMED SLIGHTLY TO IMPROVE TRACKING
D2
1N4002
VOUT –VOUT
137A TA04
R4
5k
1%
R2
5k
1%
R5**
100Ω
1%
LT317A
ADJ
VIN
+VIN VOUT +VOUT
+
2.2μF*
+
10μF
+
10μF
R1**
100Ω
1% D1
1N4002
+
2.2μF*
REG #1
ADJ
VIN
–VIN
R2
VOUT –VOUT1
137A TA02
R1
120Ω
1N4002
C1
1μF
SOLID
TANTALUM
+
C3
10μF
+2μF
REG #2
LT137A
LT137A
ADJ
VIN VOUT –VOUT2
137A TA02
1N4002
1μF
SOLID
TANTALUM
+2μF +
REG #N
LT137A
ADJ
VIN VOUT –VOUT3
137A TA02
1μF
SOLID
TANTALUM
+2μF +
LT137A/LM137
LT337A/LM337
10
137afb
SCHEMATIC DIAGRAM
Q16
Q5
Q28
VIN
0.02Ω
VOUT
137A SD
250Ω
Q26
Q25
100Ω
100Ω
12k
12k
10Ω
Q22
480Ω
2pF
5pF
Q12
Q11
Q30
Q29
220Ω
500Ω2.4k
2k
Q31
1k
Q27
1k
6k
Q34
Q23
6.8k
150Ω
15k
Q24
2k
5k
2k
20k
Q4
20Ω
800Ω
D4
600Ω
18k
100k
25pF
15pF
D3D2
D5
ADJ
Q2
D1
Q1
Q3
Q8
2k
Q9
Q10
Q33
Q32
20Ω
15pF
100k
60k
750Ω
Q6 Q7
Q21
Q20
Q19
Q17
Q15
20k
12k
8k
600Ω 4k
1k
270Ω
4.2k
Q13
Q14
4k
Q18
11
137afb
LT137A/LM137
LT337A/LM337
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
PACKAGE DESCRIPTION
.016 – .019**
(0.406 – 0.483)
DIA
.050
(1.270)
MAX .165 – .185
(4.191 – 4.699)
.500
(12.700)
MIN
.305 – .335
(7.747 – 8.509)
.350 – .370
(8.890 – 9.398)
.200
(5.080)
TYP
45o
H3(TO-39) 0801
.100
(2.540)
.100
(2.540)
.029 – .045
(0.737 – 1.143)
.028 – .034
(0.711 – 0.864)
REFERENCE
PLANE *
LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE
AND .050" BELOW THE REFERENCE PLANE
FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS .016 – .024
(0.406 – 0.610)
*
**
PIN 1
K2 (TO-3) 0801
.038 – .043
(0.965 – 1.09)
.060 – .135
(1.524 – 3.429)
.320 – .350
(8.13 – 8.89)
.420 – .480
(10.67 – 12.19)
.760 – .775
(19.30 – 19.69)
.490 – .510
(12.45 – 12.95)
R
.167 – .177
(4.24 – 4.49)
R
.151 – .161
(3.86 – 4.09)
DIA, 2PLCS
1.177 – 1.197
(29.90 – 30.40)
.655 – .675
(16.64 – 17.15)
.067 – .077
(1.70 – 1.96)
.210 – .220
(5.33 – 5.59)
.425 – .435
(10.80 – 11.05)
H Package
3-Lead TO-39 Metal Can
(Reference LTC DWG # 05-08-1330)
K Package
2-Lead TO-3 Metal Can
(Reference LTC DWG # 05-08-1310)
OBSOLETE PACKAGES
LT137A/LM137
LT337A/LM337
12
137afb
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
© LINEAR TECHNOLOGY CORPORATION 1983
LT 0807 REV B • PRINTED IN USA
M(DD3) (STRAIGHT) 0801
.045 – .055
(1.143 – 1.397)
.165 – .180
(4.191 – 4.572)
.050
(1.270)
TYP
.090 – .110
(2.286 – 2.794)
.013 – .023
(0.330 – 0.584)
.095 – .115
(2.413 – 2.921)
.028 – .038
(0.711 – 0.965)
.520 – .570
(13.208 – 14.478)
.218 – .252
(5.537 – 6.401)
.330 – .370
(8.382 – 9.398)
.060
(1.524)
TYP
.390 – .415
(9.906 – 10.541)
15° TYP
.420
.350
.565
.090
.070 TYP
.100 BSC
.420
.276
.325
.205
.080
.565
.090
.070 TYP
.100 BSC
RECOMMENDED SOLDER PAD LAYOUT
FOR THICKER SOLDER PASTE APPLICATIONS
RECOMMENDED SOLDER PAD LAYOUT
NOTE:
1. DIMENSIONS IN INCH/(MILLIMETER)
2. DRAWING NOT TO SCALE
.320
.100
(2.540)
BSC .028 – .038
(0.711 – 0.965)
T3 (TO-220) 0801
.045 – .055
(1.143 – 1.397)
.165 – .180
(4.191 – 4.572)
.095 – .115
(2.413 – 2.921)
.013 – .023
(0.330 – 0.584)
.520 – .570
(13.208 – 14.478)
.980 – 1.070
(24.892 – 27.178)
.218 – .252
(5.537 – 6.401)
.050
(1.270)
TYP
.147 – .155
(3.734 – 3.937)
DIA
.390 – .415
(9.906 – 10.541)
.330 – .370
(8.382 – 9.398)
.460 – .500
(11.684 – 12.700)
.570 – .620
(14.478 – 15.748)
.230 – .270
(5.842 – 6.858)
M Package
3-Lead Plastic DD Pak
(Reference LTC DWG # 05-08-1460)
PACKAGE DESCRIPTION
T Package
3-Lead Plastic TO-220
(Reference LTC DWG # 05-08-1420)
