LM185/LM285/LM385
Adjustable Micropower Voltage References

General Description

The LM185/LM285/LM385 are micropower 3-terminal ad-
justable band-gap voltage reference diodes. Operating from
1.24 to 5.3V and over a 10µA to 20mA current range, they
feature exceptionally low dynamic impedance and good tem-
perature stability. On-chip trimming is used to provide tight
voltage tolerance. Since the LM185 band-gap reference
uses only transistors and resistors, low noise and good
long-term stability result.

Careful design of the LM185 has made the device tolerant of
capacitive loading, making it easy to use in almost any refer-
ence application. The wide dynamic operating range allows
its use with widely varying supplies with excellent regulation.

The extremely low power drain of the LM185 makes it useful
for micropower circuitry. This voltage reference can be used
to make portable meters, regulators or general purpose ana-
log circuitry with battery life approaching shelf life. Further,
the wide operating current allows it to replace older refer-
ences with a tighter tolerance part.

The LM185 is rated for operation over a -55°C to 125°C tem-
perature range, while the LM285 is rated -40°C to 85°C and
the LM385 0°C to 70°C. The LM185 is available in a hermetic
TO-46 package and a leadless chip carrier package, while
the LM285/LM385 are available in a low-cost TO-92 molded
package, as well as S.O.

Features

Adjustable from 1.24V to 5.30V

Operating current of 10µA to 20mA

1% and 2% initial tolerance

dynamic impedance

Low temperature coefficient

Connection Diagrams

TO-92

Plastic Package

DS005250-9

Bottom View

TO-46

Metal Can Package

DS005250-1

Bottom View

SOIC Package

DS005250-10

Top View

20-Leadless Chip Carrier

DS005250-15

Top View

February 2000

LM185/LM285/LM385

Adjustable

Micropower

oltage

Reference

DS005250

www.national.com

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 2)

Reverse Current

30mA

Forward Current

10mA

Operating Temperature Range (Note 3)

LM185 Series

-55°C to 125°C

LM285 Series

-40°C to 85°C

LM385 Series

0°C to 70°C

Storage Temperature

-55°C to 150°C

Soldering Information

TO-92 Package (10 sec.)

260°C

TO-46 Package (10 sec.)

300°C

SO Package

Vapor Phase (60 sec.)

215°C

Infrared (15 sec.)

220°C

See An-450 "Surface Mounting Methods and Their Effect
on Product Reliability" for other methods of soldering
surface mount devices.

Electrical Characteristics

(Note 4)

Parameter

Conditions

LM185, LM285

LM385

Typ

LM185BX,

LM185BY

Typ

LM385BX,

LM185B,

LM285BX,

LM285

LM385BY

LM385

Units

LM285BY

(Limit)

Tested

Design

Tested

Design

Tested

Design

Tested

Design

Limit

(Note 5)

(Note 6)

(Note 5)

(Note 6)

(Note 5)

(Note 6)

(Note 5)

(Note 6)

Reference Voltage

IR = 100µA

1.240

1.252

1.265

1.270

1.240

1.252

1.255

1.265

1.270

1.255

(max)

1.228

1.215

1.205

1.228

1.215

1.215

1.205

1.215

(min)

Reference Voltage

IMIN

1mA

0.2

1.5

0.2

1.5

Change with Current

1mA

20mA

(max)

Dynamic Output

IR = 100µA,

f = 100Hz

Impedance

IAC = 0.1 IR

VOUT =

VREF

0.3

0.4

VOUT = 5.3V

0.7

Reference Voltage

IR = 100µA

Change with Output

(max)

Voltage

Feedback Current

(max)

Minimum Operating

VOUT = VREF

µA

Current (see curve)

VOUT = 5.3V

(max)

Output Wideband

IR = 100µA, 10Hz

10kHz

Noise

VOUT = VREF

µVrms

VOUT = 5.3V

170

Average
Temperature

IR = 100µA

X Suffix

ppm/°c

Coefficient (Note 7)

Y Suffix

(max)

All Others

150

Long Term Stability

IR = 100µA, T = 1000 Hr,

ppm

TA = 25°C

0.1°C

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is in-
tended to be 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.

Note 2: Refer to RETS185H for military specifications.

Note 3: For elevated temperature operation, T

max is:

LM185

150°C

LM285

125°C

LM385

100°C

Thermal Resistance

TO-92

TO-46

SO-8

JA (Junction to Ambient)

180°C/W (0.4" leads)

440°C/W

165°C/W

170°C/W (0.125" leads)

JC (Junction to Case)

N/A

80°C/W

N/A

LM185/LM285/LM385

www.national.com

Electrical Characteristics

(Note 4) (Continued)

Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at T

= T

= 25°C. Unless otherwise specified, all param-

eters apply for V

REF

OUT

5.3V.

Note 5: Guaranteed and 100% production tested.

Note 6: Guaranteed, but not 100% production tested. These limits are not to be used to calculate average outgoing quality levels.

Note 7: The average temperature coefficient is defined as the maximum deviation of reference voltage at all measured temperatures from T

MIN

to T

MAX

, divided by

MAX

- T

MIN

. The measured temperatures are -55, -40, 0, 25, 70, 85, 125°C.

Typical Performance Characteristics

Temperature Drift of 3
Representative Units

DS005250-16

Feedback Current

DS005250-17

Minimum Operating Current

DS005250-18

Reverse Characteristics

DS005250-19

Reverse Characteristics

DS005250-20

Forward Characteristics

DS005250-21

Output Noise Voltage

DS005250-22

Dynamic Output Impedance

DS005250-23

Response Time

DS005250-24

LM185/LM285/LM385

Ð­Ð»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LM185BH/883

ÐÐ»ÐµÐºÑ‚Ñ€Ð¾Ð½Ð½Ñ‹Ð¹ ÐºÐ¾Ð¼Ð¿Ð¾Ð½ÐµÐ½Ñ‚: LM185BH/883