Datasheet LM337MT Datasheet (Motorola)

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The LM337M is an adjustable three–terminal negative voltage regulator
capable of supplying in excess of 500 mA 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 LM337M 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 LM337M can be used as a precision current regulator.

• Output Current in Excess of 500 mA

• Output Adjustable Between –1.2 V and –37 V

• Internal Thermal Overload Protection

• Internal Short Circuit Current Limiting

• Output Transistor Safe–Area Compensation

• Floating Operation for High Voltage Applications

• Standard 3–Lead Transistor Packages

• Eliminates Stocking Many Fixed Voltages

Order this document by LM337M/D



MEDIUM CURRENT

THREE–TERMINAL

ADJUSTABLE NEGATIVE

VOLTAGE REGULATOR

SEMICONDUCTOR

TECHNICAL DATA

T SUFFIX

PLASTIC PACKAGE

CASE 221A

Pin 1. Adjust

2. V

3. V

in
out

1

2

3

Standard Application

I

PROG

I

Adj

LM337M

V

out

R2

Adjust

+

R1

120

V

out

µ

F solid tantalum or 10 µF aluminum

–1.25 Vǒ1

)

Cin *+1.0

–V

in

*Cin is required if regulator is located more than 4

**A 1.0

**CO is necessary for stability. A 1.0

**electrolytic is recommeded.

MOTOROLA ANALOG IC DEVICE DATA

µ

F

V

in

µ

F solid tantalum or 10 µF aluminum electrolytic is recommended.

+

CO **

R2
R1

1.0µF

″

from power supply filter.

Ǔ

–V

out

ORDERING INFORMATION

Device Package

LM337MT Plastic Power

 Motorola, Inc. 1996 Rev 1

Operating

Temperature Range

TJ = 0° to +125°C

1

MAXIMUM RATINGS

Rating Symbol Value Unit

Input–Output V oltage Differential VI–V
Power Dissipation P
Operating Junction Temperature Range T
Storage Temperature Range T

O

D

J

stg

LM337M

40 Vdc

Internally Limited W

0 to +125 °C

–65 to +150 °C

ELECTRICAL CHARACTERISTICS (|V

Characteristics

Line Regulation (Note 3)

TA = 25°C, 3.0 V ≤ |VI–VO| ≤ 40 V

Load Regulation (Note 3)

TA = 25°C, 10 mA ≤ IO ≤ 0.5 A

|VO| ≤ 5.0V
|VO| ≥ 5.0V

Thermal Regulation

10 ms Pulse, TA = 25°C
Adjustment Pin Current 3 I
Adjustment Pin Current Change

2.5 V ≤ |VI–VO| ≤ 40 V, 10 mA ≤ IL ≤ 0.5 A,

PD ≤ P
Reference Voltage

3.0 V ≤ |VI–VO| ≤ 40 V, 10 mA ≤ IO ≤ 0.5 A,

PD ≤ P

T

Line Regulation (Note 3)

3.0 V ≤ |VI–VO| ≤ 40 V

Load Regulation (Note 3)

10 mA ≤ IO ≤ 0.5 A

|VO| ≤ 5.0 V

|VO| ≥ 5.0 V
Temperature Stability (T
Minimum Load Current to Maintain Regulation

(|VI–VO| ≤ 10 V)
(|VI–VO| ≤ 40 V)

Maximum Output Current

|VI–VO| ≤ 15 V, PD ≤ P
|VI–VO| ≤ 40 V, PD ≤ P

RMS Noise, % of V

TA = 25°C, 10 Hz ≤ f ≤ 10 kHz

Ripple Rejection, VO = –10 V, f = 120 Hz (Note 4)

Without C
C

Adj

Long Term Stability, TJ = T

TA = 25°C for Endpoint Measurements

Thermal Resistance, Junction–to–Case – R

NOTES: 1.T

, TA = 25°C

max

, TA = 25°C

max

to T

low

high

≤ TJ ≤ T

low

max

, TJ = 25°C

max

O

Adj

= 10 µF

(Note 5)

high

to T

low

2.P

max

3 Load and line regulation are specified at constant junction temperature. Changes in VO due to heating effects must be taken into account separately.

Pulse testing with low duty cycle is used.

4.C

Adj

5.Since Long T erm Stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability
from lot to lot.

= 0° to +125°C

high

= 7.5 W

, when used, is connected between the adjustment pin and ground.

– VO| = 5.0 V , IO = 0.1; TJ = T

I

low

to T

Figure Symbol Min Typ Max Unit

1 Reg

2 Reg

– Reg

1, 2 ∆I

3 V

1 Reg

2 Reg

) 3 T

high

3 I

3 I

– N – 0.003 – %/V

4 RR

3 S – 0.3 1.0 %/1.0 k

[Note 1], P

high

line

load

therm

Adj

Adj

ref

line

load

S

Lmin

max

ΘJC

per Note 2, unless otherwise noted.)

max

– 0.01 0.04 %/V

–
–

15

0.3

15

1.0

– 0.03 0.04 % VO/W

– 65 100 µA
– 2.0 5.0 µA

–1.213

–1.20

–1.250

–1.25

–1.287

–1.30

– 0.02 0.07 %/V

–
–

20

0.3

70

1.5

– 0.6 – %/V

–
–

0.5

0.1

–

66

1.5

2.5

0.9

0.25

60
77

6.0
10

– 7.0 – °C/W

mV

%/V

O

V

mV

%/V

O

O

mA

A
–
–

O

dB
–
–

Hrs

2

MOTOROLA ANALOG IC DEVICE DATA

LM337M

Schematic Diagram

750 60k 100k

4.0k

1.0k

9.6k

270

8.0k

2.9k

600

4.0k

18k

20k

100

2.5k

500

800

6.0k

100k

2.4k

50k

100pF

810

15pF

3.0k

10k

2.2k

15

2.0k

21k

2.0k

5.0pF

15pF

5.0k

500

800

25pF

18k

240

220

155

100

30k

2.0
pF

60

250

15

Adjust

V

0.2

0.1
V

out

in

Figure 1. Line Regulation and ∆I

C

1.0µF

in

* Pulse Testing Required:

1% Duty Cycle is suggested.

*

V

EE

MOTOROLA ANALOG IC DEVICE DATA

/Line Test Circuit

Adj

R2 1%

+

C

1.0

µ

I

Adj

Adjust

V

in

LM337M

V

IH

V

IL

R1

V

out

Line Regulation (%/VO) =

O

120

1%

F

R

|VOL – VOH|

|VOH|

L

V

OH

V

OL

x 100

3

LM337M

Figure 2. Load Regulation and ∆I

R2 1%

CO+

C

in

–V

in

Load Regulation (mV) = VO (min Load) – VO (max Load) Load Regulation (%/VO) =

1.0

V

in

µ

F

Adjust

LM33M

I

Adj

120

R1

1%

V

out

I

L

1.0

µ

/Load Test Circuit

Adj

F

*

R

L

(max
Load)

Figure 3. Standard T est Circuit

1%

R2

* Pulse Testing required:

1% Duty Cycle is suggested.

–VO (min Load)
VO (max Load)

VO (min Load) – VO(max Load)

VO (min Load)

x 100

To Calculate R2:

V

O

R2 =

This assumes I

V

ref

14.3V

– 1

Adj

C

V

is negligible.

in

I

R

1

C

in

1.0

µ

F

I

Adj

Adjust

V

in

LM337M

Pulse Testing Required: 1% Duty Cycle is suggested.

V

ref

V

out

Figure 4. Ripple Rejection T est Circuit

C

120

1.0µF

V

in

Adjust

LM337M

1%R2

R1

V

out

Adj

I

L

+

10

1N4002D1 *

R1 120

µ

F

C

O

C

+

O

1.0µF

+

1.0µF

R

L

V

= –1.25 V

out

V

R

L

O

V

O

4.3V
f = 120 Hz

*D1 Discharges C

4

if Output is shorted to Ground.

Adj

MOTOROLA ANALOG IC DEVICE DATA

0.2
0

–0.2
–0.4
–0.6
–0.8
–1.0

, OUTPUT VOLTAGE CHANGE (%)

O

V

–1.2

∆

–1.4

–50 –25 0 25 50 75 100 125 150

Figure 7. Adjustment Pin Current Figure 8. Dropout Voltage

80

A)I

75

µ

70
65
60
55

50

, ADJUSTMENT CURRENT (

Adj

45
40

–50 –25 0 25 50 75 100 125 150

LM337M

Figure 5. Load Regulation Figure 6. Current Limit

4

Vin = –15 V
V

= –10 V

out

TJ, JUNCTION TEMPERATURE (°C)

TJ, JUNCTION TEMPERATURE (

IL = 0.5 A

°

C)

3

TJ = 25

°

C

2

°

TJ = 150

1

, OUTPUT CURRENT (A)

O

I

0

010203040

3.0

2.5

2.0

, INPUT–OUTPUT VOLTAGE

out

–V

in

V

DIFFERENTIAL (Vdc)

1.5

1.0

IL = 200 mA

–50 –25 0 25 50 75 100 125 150

C

VI – VO, INPUT VOLTAGE DIFFERENTIAL (Vdc)

V

= –5.0 V

out

∆

V

= 100 mV

out

TJ, JUNCTION TEMPERATURE (

T

= 55°C

J

IL = 20 mA

°

C)

IL = 500 mA

Figure 9. T emperature Stability Figure 10. Minimum Operating Current

1.270

1.260

1.250

1.240

ref

V , REFERENCE VOLTAGE (V)

1.230
–50 –25 0 25 50 75 100 125 150

TJ, JUNCTION TEMPERATURE (

MOTOROLA ANALOG IC DEVICE DATA

1.8

1.6

1.4

1.2

1.

0

0.8

0.6

, QUIESCENT CURRENT (mA)

0.4

B

I

0.2
0

0 10203040

°

C)

V

, INPUT–OUTPUT VOLTAGE DIFFERENTIAL (Vdc)

in–Vout

TJ = –55°C

TJ = 25

TJ = 150

°

C

°

C

5

LM337M

Figure 11. Ripple Rejection versus Output Voltage Figure 12. Ripple Rejection versus Output Current

100

80

60

C

= 10 µF

Adj

Without C

Adj

100

80

60

C

= 10 µF

Adj

Without C

Adj

40

RR, RIPPLE REJECTION (dB)

20

0

0 –5 –10 –15 –20 –25 –30 –35 –40

Vin – V

= 5.0 V

out

IL = 500 mA
f = 120 Hz

°

C

TJ = 25

VO, OUTPUT VOLTAGE (V)

40

Vin = –15 V
V

= –10 V

out

20

RR, RIPPLE REJECTION (dB)

f = 120 Hz

°

C

TJ = 25

0

0.01 0.1 1.0 10
IO, OUTPUT CURRENT (A)

Figure 13. Ripple Rejection versus Frequency Figure 14. Output Impedance

100

80

C

= 10 µF

Adj

60

40

Without C

Adj

RR, RIPPLE REJECTION (dB)

Vin = –15 V

20

V

= –10 V

out

IL = 500 mA

°

C

TJ = 25

0

10 100 1.0 k 10 k 100 k 1.0 M 10 M

f, FREQUENCY (Hz)

1

10

Vin = –15 V
V

= –10 V

Ω

10

10

, OUTPUT IMPEDANCE ( )

O

Z

10

out

IL = 500 mA

0

10

–1

–2

–3

10 100 1.0 k 10 k 100 k 1 M

CL = 1.0
TJ = 25

Without C

µ

F

°

C

Adj

C

= 10µF

Adj

f, FREQUENCY (Hz)

0.8

0.6

0.4

, OUTPUT VOL TAGE

DEVIATION (V)

0.2

out

V

∆

0
–0.2
–0.4

0

–0.5

CHANGE (V)

, INPUT VOLTAGE

–1.0

in

V

∆

6

Figure 15. Line Transient Response Figure 16. Load Transient Reponse

0.6

Without C

Adj

C

= 10 µF

Adj

V

= –10 V

out

IL = 50 mA

°

C

TJ = 25

µ

CL = 1.0

010203040

F

t, TIME (

µ

s)

, OUTPUT VOL TAGE

out

V

∆

, LOAD

L

I

0.4

0.2
0

–0.2

DEVIATION (V)

–0.4
–0.6

0

–0.5
–1.0

CURRENT (A)

–1.5

010203040

Without C

Adj

C

= 10

µ

Adj

F

Vin = –15 V
V

out

INL = 50 mA
TJ = 25
CL = 1.0

= –10 V

°

C

µ

F

t, TIME (µs)

MOTOROLA ANALOG IC DEVICE DATA

LM337M

APPLICATIONS INFORMATION

Basic Circuit Operation

The LM337M is a three–terminal floating regulator. In
operation, the LM337M develops and maintains a nominal
–1.25 V reference (V

) between its output and adjustment

ref

terminals. This reference voltage is converted to a
programming current (I

) by R1 (see Figure 17), and this

PROG

constant current flows through R2 to ground. The regulated
output voltage is given by:

R

V

= V

out

ref

Since the current into the adjustment terminal (I

2

(1 + ) + I

R

1

Adj R2

Adj

represents an error term in the equation, the LM337M was
designed to control I

to less than 100 µA and keep it

Adj

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 LM337M 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

+

R

2

I

I

Adj

Adjust

V

in

LM337M

V

ref

V

out

V

= –1.25 V Typically

ref

PRONG

R

1

+

C

V

O

out

–

Load Regulation

The LM337M 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 (C

) prevents ripple

Adj

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 LM337M with the recommended
protection diodes for output voltages in excess of –25 V or
high capacitance values (CO > 25 µF, C

> 10 µF). Diode D

Adj

prevents CO from discharging thru the IC during an input
short circuit. Diode D2 protects against capacitor C
discharging through the IC during an output short circuit. The
combination of diodes D1 and D2 prevents C
discharging through the IC during an input short circuit.

Figure 18. V oltage Regulator with

Protection Diodes

C

Adj

+

D

2

1N4002

C

–V

R

2

+

C

in

in

V

in

Adjust

LM337M

D

1

1N4002

R

1

V

out

1

Adj

from

Adj

+

+

V

O

out

–

MOTOROLA ANALOG IC DEVICE DATA

7

LM337M

OUTLINE DIMENSIONS

T SUFFIX

PLASTIC PACKAGE

CASE 221A–06

ISSUE Y

SEATING

–T–

PLANE

B

4

Q

123

F

T

A

U

C

S

H

K

Z

L

V

R

J

G

D

N

NOTES:

1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.

2. CONTROLLING DIMENSION: INCH.

3. DIMENSION Z DEFINES A ZONE WHERE ALL
BODY AND LEAD IRREGULARITIES ARE
ALLOWED.

DIM MIN MAX MIN MAX

A 0.570 0.620 14.48 15.75
B 0.380 0.405 9.66 10.28
C 0.160 0.190 4.07 4.82
D 0.025 0.035 0.64 0.88
F 0.142 0.147 3.61 3.73
G 0.095 0.105 2.42 2.66
H 0.110 0.155 2.80 3.93
J 0.018 0.025 0.46 0.64
K 0.500 0.562 12.70 14.27
L 0.045 0.060 1.15 1.52
N 0.190 0.210 4.83 5.33
Q 0.100 0.120 2.54 3.04
R 0.080 0.110 2.04 2.79
S 0.045 0.055 1.15 1.39
T 0.235 0.255 5.97 6.47
U 0.000 0.050 0.00 1.27
V 0.045 ––– 1.15 –––
Z ––– 0.080 ––– 2.04

MILLIMETERSINCHES

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. “T ypical” 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/Affirmative Action Employer.

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8

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MOTOROLA ANALOG IC DEVICE DATA

LM337M/D

*LM337M/D*