Order this document by LM337/D
Device Operating
Temperature Range Package
ORDERING INFORMATION
LM337D2T
LM337T
Surface Mount
Insertion Mount
LM337BD2T
LM337BT TJ = –40° to +125°CSurface Mount
Insertion Mount
TJ = 0° to +125°C
SEMICONDUCTOR
TECHNICAL DATA
THREE–TERMINAL
ADJUSTABLE NEGATIVE
VOLTAGE REGULATOR
Pin 1. Adjust
2. Vin
3. Vout
T SUFFIX
PLASTIC PACKAGE
CASE 221A
Heatsink surface
connected to Pin 2.
3
12
D2T SUFFIX
PLASTIC PACKAGE
CASE 936
(D2PAK)
Heatsink surface (shown as terminal 4 in
case outline drawing) is connected to Pin 2.
3
12
1
MOTOROLA ANALOG IC DEVICE DATA
The LM337 is an adjustable 3–terminal negative voltage regulator
capable of supplying in excess of 1.5 A over an output voltage range of
–1.2 V to –37 V. This voltage regulator is exceptionally easy to use and
requires only two external resistors to set the output voltage. Further, it
employs internal current limiting, thermal shutdown and safe area
compensation, making it essentially blow–out proof.
The LM337 serves a wide variety of applications including local, on card
regulation. This device can also be used to make a programmable output
regulator, or by connecting a fixed resistor between the adjustment and
output, the LM337 can be used as a precision current regulator.
•Output Current in Excess of 1.5 A
•Output Adjustable between –1.2 V and –37 V
•Internal Thermal Overload Protection
•Internal Short Circuit Current Limiting Constant with Temperature
•Output Transistor Safe–Area Compensation
•Floating Operation for High Voltage Applications
•Eliminates Stocking many Fixed Voltages
•Available in Surface Mount D2PAK and Standard 3–Lead Transistor
Package
Standard Application
Vout
+
–1.25 V
ǒ
1
)
R2
R1
Ǔ
*Cin is required if regulator is located more than 4 inches from power supply filter.
*A 1.0
µ
F solid tantalum or 10
µ
F aluminum electrolytic is recommended.
**CO is necessary for stability. A 1.0
µ
F solid tantalum or 10
µ
F aluminum electrolytic
**is recommeded.
LM337
IPROG
Cin*
1.0
µ
F
+
–Vin Vin Vout –Vout
CO**
1.0
µ
F
+
IAdj
R1
120
R2
Motorola, Inc. 1996 Rev 1
LM337
2MOTOROLA ANALOG IC DEVICE DATA
MAXIMUM RATINGS
Rating Symbol Value Unit
Input–Output Voltage Differential VI–VO40 Vdc
Power Dissipation
Case 221A
TA = +25°C PDInternally Limited W
Thermal Resistance, Junction–to–Ambient θJA 65 °C/W
Thermal Resistance, Junction–to–Case θJC 5.0 °C/W
Case 936 (D2PAK)
TA = +25°C PDInternally Limited W
Thermal Resistance, Junction–to–Ambient θJA 70 °C/W
Thermal Resistance, Junction–to–Case θJC 5.0 °C/W
Operating Junction Temperature Range TJ–40 to +125 °C
Storage Temperature Range Tstg –65 to +150 °C
ELECTRICAL CHARACTERISTICS (|VI–VO| = 5.0 V; IO = 0.5 A for T package; TJ = Tlow to Thigh [No te 1]; Imax and Pmax [Note 2].)
Characteristics Figure Symbol Min Typ Max Unit
Line Regulation (Note 3), TA = +25°C, 3.0 V ≤ |VI–VO| ≤ 40 V 1 Regline –0.01 0.04 %/V
Load Regulation (Note 3), TA = +25°C, 10 mA ≤ IO ≤ Imax
|VO| ≤ 5.0 V
|VO| ≥ 5.0 V
2 Regload –
–15
0.3 50
1.0 mV
% VO
Thermal Regulation, TA = +25°C (Note 6), 10 ms Pulse Regtherm –0.003 0.04 % VO/W
Adjustment Pin Current 3 IAdj –65 100 µA
Adjustment Pin Current Change, 2.5 V ≤ |VI–VO| ≤ 40 V,
10 mA ≤ IL ≤ Imax, PD ≤ Pmax, TA = +25°C1, 2 ∆IAdj –2.0 5.0 µA
Reference Voltage, TA = +25°C, 3.0 V ≤ |VI–VO| ≤ 40 V,
10 mA ≤ IO ≤ Imax, PD ≤ Pmax, TJ = Tlow to Thigh 3 Vref –1.213
–1.20 –1.250
–1.25 –1.287
–1.30 V
Line Regulation (Note 3), 3.0 V ≤ |VI–VO| ≤ 40 V 1 Regline –0.02 0.07 %/V
Load Regulation (Note 3), 10 mA ≤ IO ≤ Imax
|VO| ≤ 5.0 V
|VO| ≥ 5.0 V
2 Regload –
–20
0.3 70
1.5 mV
% VO
Temperature Stability (Tlow ≤ TJ ≤ Thigh) 3 TS–0.6 – % VO
Minimum Load Current to Maintain Regulation
(|VI–VO| ≤ 10 V)
(|VI–VO| ≤ 40 V)
3 ILmin –
–1.5
2.5 6.0
10
mA
Maximum Output Current
|VI–VO| ≤ 15 V, PD ≤ Pmax, T Package
|VI–VO| ≤ 40 V, PD ≤ Pmax, TJ = +25°C, T Package
3 Imax –
–1.5
0.15 2.2
0.4
A
RMS Noise, % of VO, TA = +25°C, 10 Hz ≤ f ≤ 10 kHz N – 0.003 – % VO
Ripple Rejection, VO = –10 V, f = 120 Hz (Note 4)
Without CAdj
CAdj = 10 µF
4RR –
66 60
77 –
–
dB
Long–Term Stability , TJ = Thigh (Note 5), TA = +25°C for
Endpoint Measurements 3 S – 0.3 1.0 %/1.0 k
Hrs.
Thermal Resistance Junction–to–Case, T Package RθJC –4.0 – °C/W
NOTES: 1.Tlow to Thigh = 0° to +125°C, for LM337T, D2T. Tlow to Thigh = –40° to +125°C, for LM337BT, BD2T.
2.Imax = 1.5 A, Pmax = 20 W
3.Load and line regulation are specified at constant junction temperature. Change in VO because of heating effects is covered under the Thermal
Regulation specification. Pulse testing with a low duty cycle is used.
4.CAdj, when used, is connected between the adjustment pin and ground.
5.Since Long Term Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from
lot to lot.
6.Power dissipation within an IC voltage regulator produces a temperature gradient on the die, affecting individual IC components on the die. These
effects can be minimized by proper integrated circuit design and layout techniques. Thermal Regulation is the ef fect of these temperature gradients
on the output voltage and is expressed in percentage of output change per watt of power change in a specified time.
LM337
3
MOTOROLA ANALOG IC DEVICE DATA
Representative Schematic Diagram
Figure 1. Line Regulation and ∆IAdj/Line Test Circuit
*
VOH
VOL
Line Regulation (%
ń
V)
+
|VOL–VOH|
|VOH|x 100
LM337
100
2.5k 2.0k
60
810
10k
15pF
800
220
5.0k
75
060k 100k
18k
800
4.0k
6.0k
1.0k
9.6k 3.0k 2.2k
100
18k
21k
270 100pF 5.0pF 240 2.0
pF 250
8.0k 20k
100k 5.0k 0.2
15
600 2.9k 4.0k 500 2.4k 15 155 0.05
Vin
500
Adjust
Vout
2.0k
25pF
15pF
Cin 1.0
µ
F
R21%
CO+
RL
Adjust
Vin Vout
R1120
1%
VEE
* Pulse testing required.
1% Duty Cycle
is suggested.
1.0
µ
F
VIH
VIL
IAdj
This device contains 39 active transistors.
30k
LM337
4MOTOROLA ANALOG IC DEVICE DATA
Figure 2. Load Regulation and ∆IAdj/Load Test Circuit
Figure 3. Standard Test Circuit
Figure 4. Ripple Rejection Test Circuit
VO (min Load) – VO (max Load)
Cin 1.0
µ
F
R21%
R1120
CO+
RL
(max
Load)
Adjust
Vin
–VILM337 Vout
* Pulse testing required.
1% Duty Cycle is suggested.
Load Regulation (mV) = VO (min Load) – VO (max Load) Load Regulation (% VO) = x 100
IL
IAdj 1.0
µ
F
–VO (min Load)
–VO (max Load)
VO
RL
+1.0
µ
F
CO
R1120
1%
R2
Cin
Adjust
Vin LM337
To Calculate R2:R2 = – 1 R1
This assumes IAdj is negligible. * Pulse testing required.
* 1% Duty Cycle is suggested.
VI
IAdj Vref
IL
VO
1.0
µ
F
Vout
RL
+1.0
µ
F
CO
1N4002D1*
Cin
1%R2
Adjust
Vin LM337
R1120
14.3 V
4.3 V f = 120 Hz
CAdj +
Vout = –1.25 V
* D1 Discharges CAdj if output is shorted to Ground.
1.0
µ
F
10
µ
F
Vout
VO
*
VO (min Load)
Vref
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Af firmative Action Employer .
LM337
5
MOTOROLA ANALOG IC DEVICE DATA
Figure 5. Load Regulation Figure 6. Current Limit
Figure 7. Adjustment Pin Current Figure 8. Dropout Voltage
Figure 9. Temperature Stability Figure 10. Minimum Operating Current
∆
Vout, OUTPUT VOLT AGE CHANGE (%)
IL = 0.5 A
IL = 1.5 A
Vin = –15 V
Vout = –10 V
Iout, OUTPUT CURRENT (A)
TJ = 25
°
C
, ADJUSTMENT CURRENT (
Adj
µ
A)I
Vin out, INPUT–OUTPUT VOL TAGE– V
1.0 A
500 mA
200 mA
20 mA
Vout = –5.0 V
∆
VO = 100 mV
IL = 1.5 A
Vref, REFERENCE VOLTAGE (V)
, QUIESCENT CURRENT (mA)
B
I
TJ = 25
°
C
DIFFERENTIAL (Vdc)
0.2
0
–0.2
–0.4
–0.6
–0.8
–1.0
–1.2
–1.4
4.0
3.0
2.0
1.0
0
80
75
70
65
60
55
50
45
40
3.0
2.5
2.0
1.5
1.0
1.27
1.26
1.25
1.24
1.23
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
–50 –25 0 25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (
°
C) 010203040
V
in–Vout , INPUT–OUTPUT VOLTAGE DIFFERENTIAL (Vdc)
–50 –25 0 25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (
°
C) –50 –25 0 25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (
°
C)
–50 –25 0 25 50 75 100 125 150
TJ, JUNCTION TEMPERATURE (
°
C) 10 20 30 400 Vin–Vout , INPUT–OUTPUT VOLT AGE DIFFERENTIAL (Vdc)
LM337
6MOTOROLA ANALOG IC DEVICE DATA
Figure 11. Ripple Rejection versus Output Voltage Figure 12. Ripple Rejection versus Output Current
Figure 13. Ripple Rejection versus Frequency Figure 14. Output Impedance
Figure 15. Line Transient Response Figure 16. Load Transient Reponse
010203040
t, TIME (
µ
s)
V
VOLT AGE CHANGE (V)
∆
in
∆
V
VOLT AGE DEVIATION (V)
out
, INPUT , OUTPUT
∆
V
VOLT AGE DEVIATION (V)
out
I
CURRENT (A)
L, LOAD , OUTPUT
010203040
t, TIME (
µ
s)
Vout = –10 V
IL = 50 mA
TJ = 25
°
C
CL = 1.0
µ
F
Without CAdj
0 –5.0 –10 –15 –20 –25 –30 –35 –40
RR, RIPPLE REJECTION (dB)
Vout, OUTPUT VOLTAGE (V) 0.01 0.1 1.0 10
RR, RIPPLE REJECTION (dB)
IO, OUTPUT CURRENT (A)
10 100 1.0 k 10 k 100 k 1.0 M 10 M
RR, RIPPLE REJECTION (dB)
f, FREQUENCY (Hz) 10 100 1.0 k 10 k 100 k 1.0 M
, OUTPUT IMPEDANCE ( )
O
Ω
f, FREQUENCY (Hz)
Z
CAdj = 10
µ
F
0.8
0.6
0.4
0.2
0
–0.2
–0.4
0
–0.5
–1.0
–0.5
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
0
–1.0
–1.5
100
80
60
40
20
0
100
80
60
40
20
0
100
80
60
40
0
20
101
100
10–1
10–2
10–3
Without CAdj
CAdj = 10
µ
F
Vin = –15 V
Vout = –10 V
IL = 50 mA
TJ = 25
°
C
CL = 1.0
µ
F
CAdj = 10
µ
F
Vin – Vout = 5.0 V
IL = 500 mA
f = 120 Hz
TJ = 25
°
C
Without CAdj Without CAdj
CAdj = 10
µ
F
Vin = –15 V
Vout = –10 V
f = 120 Hz
TJ = 25
°
C
CAdj =10
µ
F
Without CAdj
Vin = –15 V
Vout = –10 V
IL = 500 mA
TJ = 25
°
C
Without CAdj
CAdj = 10
µ
F
Vin = –15 V
Vout = –10 V
IL = 500 mA
CL = 1.0
µ
F
TJ = 25
°
C
LM337
7
MOTOROLA ANALOG IC DEVICE DATA
APPLICATIONS INFORMATION
Basic Circuit Operation
The LM337 is a 3–terminal floating regulator . In operation,
the LM337 develops and maintains a nominal –1.25 V
reference (V ref) between its output and adjustment terminals.
This reference voltage is converted to a programming current
(IPROG) by R1 (see Figure 17), and this constant current flows
through R2 from ground.
The regulated output voltage is given by:
Vout
+
Vref
ǒ
1
)
R2
R1
Ǔ)
IAdj R2
Since the current into the adjustment terminal (IAdj)
represents an error term in the equation, the LM337 was
designed to control IAdj to less than 100 µA and keep it
constant. To do this, all quiescent operating current is
returned to the output terminal. This imposes the requirement
for a minimum load current. If the load current is less than this
minimum, the output voltage will rise.
Since the LM337 is a floating regulator, it is only the
voltage differential across the circuit which is important to
performance, and operation at high voltages with respect to
ground is possible.
Figure 17. Basic Circuit Configuration
+
–
Vout
CO
R2
IPROG
R1
Adjust
Vin LM337 Vout
+
Vref = –1.25 V Typical
Vref
Vout
IAdj
Load Regulation
The LM337 is capable of providing extremely good load
regulation, but a few precautions are needed to obtain
maximum performance. For best performance, the
programming resistor (R1) should be connected as close to
the regulator as possible to minimize line drops which
effectively appear in series with the reference, thereby
degrading regulation. The ground end of R2 can be returned
near the load ground to provide remote ground sensing and
improve load regulation.
External Capacitors
A 1.0 µF tantalum input bypass capacitor (Cin) is
recommended to reduce the sensitivity to input line
impedance.
The adjustment terminal may be bypassed to ground to
improve ripple rejection. This capacitor (CAdj) prevents ripple
from being amplified as the output voltage is increased. A
10 µF capacitor should improve ripple rejection about 15 dB
at 120 Hz in a 10 V application.
An output capacitance (CO) in the form of a 1.0 µF
tantalum or 10 µF aluminum electrolytic capacitor is required
for stability.
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.
Figure 18 shows the LM337 with the recommended
protection diodes for output voltages in excess of –25 V or
high capacitance values (CO > 25 µF, CAdj > 10 µF). Diode D1
prevents CO from discharging thru the IC during an input
short circuit. Diode D2 protects against capacitor CAdj
discharging through the IC during an output short circuit. The
combination of diodes D1 and D2 prevents CAdj from the
discharging through the IC during an input short circuit.
Figure 18. Voltage Regulator with Protection Diodes
+
–
+
Cin
–Vin
R2CAdj +
+
1N4002
LM337
Vout
Vout
Vin
D1
1N4002
R1D2CO
Adjust
Vout
Figure 19. D2PAK Thermal Resistance and Maximum
Power Dissipation versus P.C.B. Copper Length
R , THERMAL RESISTANCE
JA
θ
JUNCTION-T O-AIR ( C/W)
°
ÎÎÎÎ
ÎÎÎÎ
ÎÎÎÎ
ÎÎÎÎ
PD, MAXIMUM POWER DISSIPATION (W)
30
40
50
60
70
80
Minimum
Size Pad
2.0 oz. Copper
L
L
Free Air
Mounted
Vertically
R
θ
JA 1.0
1.5
2.0
2.5
3.0
3.5
010203025155.0
L, LENGTH OF COPPER (mm)
PD(max) for TA = +50
°
C
LM337
8MOTOROLA ANALOG IC DEVICE DATA
T SUFFIX
PLASTIC PACKAGE
CASE 221A–06
ISSUE Y
OUTLINE DIMENSIONS
MIN MINMAX MAX
INCHES MILLIMETERS
DIM
A
B
C
D
F
G
H
J
K
L
N
Q
R
S
T
U
V
Z
14.48
9.66
4.07
0.64
3.61
2.42
2.80
0.46
12.70
1.15
4.83
2.54
2.04
1.15
5.97
0.00
1.15
–
15.75
10.28
4.82
0.88
3.73
2.66
3.93
0.64
14.27
1.52
5.33
3.04
2.79
1.39
6.47
1.27
–
2.04
0.570
0.380
0.160
0.025
0.142
0.095
0.110
0.018
0.500
0.045
0.190
0.100
0.080
0.045
0.235
0.000
0.045
–
0.620
0.405
0.190
0.035
0.147
0.105
0.155
0.025
0.562
0.060
0.210
0.120
0.110
0.055
0.255
0.050
–
0.080
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIM Z DEFINES A ZONE WHERE ALL BODY AND
LEAD IRREGULARITIES ARE ALLOWED.
–T
–
SEATING
PLANE
CS
T
U
J
R
F
B
Q
H
Z
L
V
G
ND
K
A
4
123
D2T SUFFIX
PLASTIC PACKAGE
CASE 936–03
(D2PAK)
ISSUE B
5 REF5 REF
A
12 3
K
F
B
J
S
H
0.010 (0.254) T
M
D
G
C
E
–T
–
MLP
NR
V
U
TERMINAL 4
NOTES:
1 DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2 CONTROLLING DIMENSION: INCH.
3 TAB CONTOUR OPTIONAL WITHIN DIMENSIONS
A AND K.
4 DIMENSIONS U AND V ESTABLISH A MINIMUM
MOUNTING SURFACE FOR TERMINAL 4.
5 DIMENSIONS A AND B DO NOT INCLUDE MOLD
FLASH OR GATE PROTRUSIONS. MOLD FLASH
AND GATE PROTRUSIONS NOT TO EXCEED
0.025 (0.635) MAXIMUM.
DIM
AMIN MAX MIN MAX
MILLIMETERS
0.386 0.403 9.804 10.236
INCHES
B0.356 0.368 9.042 9.347
C0.170 0.180 4.318 4.572
D0.026 0.036 0.660 0.914
E0.045 0.055 1.143 1.397
F0.051 REF 1.295 REF
G0.100 BSC 2.540 BSC
H0.539 0.579 13.691 14.707
J0.125 MAX 3.175 MAX
K0.050 REF 1.270 REF
L0.000 0.010 0.000 0.254
M0.088 0.102 2.235 2.591
N0.018 0.026 0.457 0.660
P0.058 0.078 1.473 1.981
R
S0.116 REF 2.946 REF
U0.200 MIN 5.080 MIN
V0.250 MIN 6.350 MIN
__
OPTIONAL
CHAMFER
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LM337/D
*LM337/D*
◊
