LM285Z-1.2 - National Semiconductor

TL/H/5518

LM185-1.2/LM285-1.2/LM385-1.2 Micropower Voltage Reference Diode

January 1995

LM185-1.2/LM285-1.2/LM385-1.2

Micropower Voltage Reference Diode

General Description

The LM185-1.2/LM285-1.2/LM385-1.2 are micropower

2-terminal band-gap voltage regulator diodes. Operating

over a 10 mA to 20 mA current range, they feature excep-

tionally low dynamic impedance and good temperature sta-

bility. On-chip trimming is used to provide tight voltage toler-

ance. Since the LM185-1.2 band-gap reference uses only

transistors and resistors, low noise and good long term sta-

bility result.

Careful design of the LM185-1.2 has made the device ex-

ceptionally tolerant of capacitive loading, making it easy to

use in almost any reference application. The wide dynamic

operating range allows its use with widely varying supplies

with excellent regulation.

The extremely low power drain of the LM185-1.2 makes it

useful for micropower circuitry. This voltage reference can

be used to make portable meters, regulators or general pur-

pose analog circuitry with battery life approaching shelf life.

Further, the wide operating current allows it to replace older

references with a tighter tolerance part.

The LM185-1.2 is rated for operation over a b55§Cto

125§C temperature range while the LM285-1.2 is rated

b40§Cto85

C and the LM385-1.2 0§Cto70

C. The LM185-

1.2/LM285-1.2 are available in a hermetic TO-46 package

and the LM285-1.2/LM385-1.2 are also available in a low-

cost TO-92 molded package, as well as S.O. The LM185-

1.2 is also available in a hermetic leadless chip carrier pack-

age.

Features

Yg4mV(

0.3%) max. initial tolerance (A grade)

YOperating current of 10 mAto20mA

Y0.6Xmax dynamic impedance (A grade)

YLow temperature coefficient

YLow voltage referenceÐ1.235V

Y2.5V device and adjustable device also available

Ð LM185-2.5 series and LM185 series, respectively

Connection Diagrams

TO-92

Plastic Package (Z)

TL/H/5518–10

Bottom View

Order Number LM285Z-1.2,

LM285AZ-1.2, LM285AXZ-1.2,

LM285AYZ-1.2, LM285BXZ-1.2,

LM285BYZ-1.2, LM385Z-1.2,

LM385AZ-1.2, LM385AXZ-1.2,

LM385AYZ-1.2, LM385BZ-1.2,

LM385BXZ-1.2 or LM385BYZ-1.2

See NS Package Number Z03A

TO-46

Metal Can Package (H)

TL/H/5518–6

Bottom View

Order Number LM185H-1.2,

LM185H-1.2/883, LM185BXH-1.2,

LM185BYH-1.2/883, LM285H-1.2,

LM285BXH-1.2 or LM285BYH-1.2

See NS Package Number H02A

SO Package

TL/H/5518–9

Order Number LM285M-1.2,

LM285AM-1.2, LM285AXM-1.2,

LM285AYM-1.2, LM285BXM-1.2,

LM285BYM-1.2, LM385M-1.2,

LM385AM-1.2, LM385AXM-1.2,

LM385AYM-1.2, LM385BM-1.2,

LM385BXM-1.2 or LM385BYM-1.2

See NS Package Number M08A

SO Package

Alternate Pinout

TL/H/5518–11

Order Number LM385SM-1.2,

LM385ASM-1.2 or LM385BSM-1.2

See NS Package Number M08A

Typical Application

Wide Input

Range Reference

TL/H/5518–8

C1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

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 30 mA

Forward Current 10 mA

Operating Temperature Range (Note 3)

LM185-1.2 b55§Ctoa

125§C

LM285-1.2 b40§Ctoa

85§C

LM385-1.2 0§Cto70

Storage Temperature b55§Ctoa

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 sur-

face mount devices.

Electrical Characteristics (Note 4)

Parameter Conditions

LM285A-1.2 LM385A-1.2

(Limit)

Units

LM285AX-1.2 LM385AX-1.2

LM285AY-1.2 LM385AY-1.2

Tested Design Tested Design

Typ Limit Limit Typ Limit Limit

(Notes 5, 8) (Note 6) (Note 5) (Note 6)

Reverse Breakdown IRe100 mA 1.235 1.231 1.235 1.231 V(Min)

Voltage 1.239 1.239 V(Max)

1.230 1.220 1.235 1.225 V(Min)

1.245 1.245 V(Max)

Minimum Operating 7810 7810 mA

Current (Max)

Reverse Breakdown IMIN sIRs1mA 1 1.5 11.5 mV

Voltage Change with (Max)

Current 1mAsI

Rs20 mA 10 20 10 20 mV

(Max)

Reverse Dynamic IRe100 mA, f e20 Hz 0.2 0.6 0.2 0.6 X

Impedance 1.5 1.5 (Max)

Wideband Noise (rms) IRe100 mA, 60 60 mV

10 Hz sfs10 kHz

Long Term Stability IRe100 mA, T e1000 Hr, 20 20 ppm

TAe25§Cg0.1§C

Average Temperature IMIN sIRs20 mA

Coefficient (Note 7) X Suffix 30 30 ppm/§C

Y Suffix 50 50 (Max)

All Others 150 150

Electrical Characteristics (Continued) (Note 4)

LM185-1.2

LM185BX-1.2 LM385B-1.2

LM185BY-1.2 LM385BX-1.2 LM385-1.2

LM285-1.2 LM385BY-1.2 Units

Parameter Conditions Typ LM285BX-1.2 (Limit)

LM285BY-1.2

Tested Design Tested Design Tested Design

Limit Limit Limit Limit Limit Limit

(Notes 5, 8) (Note 6) (Note 5) (Note 6) (Note 5) (Note 6)

Reverse Breakdown TAe25§C, 1.235 1.223 1.223 1.205 V(Min)

Voltage 10 mAsIRs20 mA 1.247 1.247 1.260 V(Max)

Minimum Operating 8 10 20 15 20 15 20 mA

Current (Max)

Reverse Breakdown 10 mAsIRs1mA 1 1.5 11.5 11.5 mV

Voltage Change with (Max)

Current 1mAsI

Rs20 mA 10 20 20 25 20 25 mV

(Max)

Reverse Dynamic IRe100 mA, f e20 Hz 1X

Impedance

Wideband Noise (rms) IRe100 mA, 60 mV

10 Hz sfs10 kHz

Long Term Stability IRe100 mA, T e1000 Hr, 20 ppm

TAe25§Cg0.1§C

Average Temperature IRe100 mA

Coefficient (Note 7) X Suffix 30 30 ppm/§C

Y Suffix 50 50 ppm/§C

All Others 150 150 150 ppm/§C

(Max)

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

intended 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-1.2 for military specifications.

Note 3: For elevated temperature operation, Tjmax is:

LM185 150§C

LM285 125§C

LM385 100§C

Thermal Resistance TO-92 TO-46 SO-8

iJA (junction to ambient) 180§C/W (0.4×leads) 440§C/W 165§C/W

170§C/W (0.125×leads)

iJC (junction to case) N/A 80§C/W N/A

Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TAeTJe25§C.

Note 5: Guaranteed and 100% production tested.

Note 6: Guaranteed, but not 100% production tested. These limits are not 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 between the operating TMAX

and TMIN, divided by TMAX bTMIN. The measured temperatures are b55§C, b40§C, 0§C, 25§C, 70§C, 85§C, 125§C.

Note 8: A military RETS electrical specification is available on request.

Typical Performance Characteristics

TL/H/5518–3

Reverse Characteristics Reverse Characteristics Forward Characteristics

Temperature Drift of 3

Representative Units Reverse Dynamic Impedance Reverse Dynamic Impedance

Noise Voltage Filtered Output Noise Response Time

Typical Applications (Continued)

Micropower Reference

from 9V Battery

Reference from

1.5V Battery

TL/H/5518–2

Micropower*5V Regulator Micropower*10V Reference

*IQj20 mA standby current

*IQj30 mA

Precision 1 mA to 1 mA Current Sources

TL/H/5518–4

*IOUT e1.23V

Typical Applications (Continued)

METER THERMOMETERS

0§Cb100§C Thermometer Lower Power Thermometer

0§Fb50§F Thermometer Micropower Thermocouple Cold Junction Compensator

*2N3638 or 2N2907 select for inverse HFE j5

²Select for operation at 1.3V

³IQj600 mAto900mA

Calibration

1. Short LM385-1.2, adjust R3 for IOUTetemp at 1 mA/§K

2. Remove short, adjust R2 for correct reading in centigrade

²IQat 1.3Vj500 mA

IQat 1.6V j2.4 mA

Calibration

TL/H/5518–5

1. Short LM385-1.2, adjust R3 for IOUTetemp at 1.8 mA/§K

2. Remove short, adjust R2 for correct reading in §FAdjustment Procedure

1. Adjust TC ADJ pot until voltage across R1 equals Kelvin temperature

multiplied by the thermocouple Seebeck coefficient.

2. Adjust zero ADJ pot until voltage across R2 equals the thermocouple

Seebeck coefficient multiplied by 273.2.

Thermocouple Seebeck R1 R2 Voltage Voltage

Type Coefficient (X)(X) Across R1 Across R2

(mV/§C) @25§C (mV)

(mV)

J 52.3 523 1.24k 15.60 14.32

T 42.8 432 1k 12.77 11.78

K 40.8 412 953X12.17 11.17

S 6.4 63.4 150X1.908 1.766

Typical supply current 50 mA

Typical Applications (Continued)

Centigrade Thermometer

TL/H/5518–1

Calibration

1. Adjust R1 so that V1 etemp at 1 mV/§K

2. Adjust V2 to 273.2 mV

²IQfor 1.3V to 1.6V battery volt-

age e50 mAto150mA

Schematic Diagram

TL/H/5518–7

Connection Diagrams (Continued)

TL/H/5518–12

Order Number LM185E-1.2/883

See NS Package Number E20A

Physical Dimensions inches (millimeters)

Order Number LM185E-1.2/883

NS Package Number E20A

Physical Dimensions inches (millimeters) (Continued)

TO-46 Metal Can Package (H)

Order Number LM185H-1.2, LM185H-1.2/883, LM185BXH-1.2, LM285H-1.2, LM285BXH-1.2 or LM285BYH-1.2

NS Package Number H02A

Small Outline (SO-8) Package

Order Number LM285M-1.2, LM285AM-1.2, LM285AXM-1.2, LM285AYM-1.2, LM285BXM-1.2,

LM285BYM-1.2, LM385M-1.2, LM385AM-1.2, LM385AXM-1.2, LM385AYM-1.2, LM385BM-1.2,

LM385BXM-1.2, LM385BYM-1.2, LM385SM-1.2, LM385ASM-1.2 or LM385BSM-1.2

NS Package Number M08A

LM185-1.2/LM285-1.2/LM385-1.2 Micropower Voltage Reference Diode

Physical Dimensions inches (millimeters) (Continued)

TO-92 Plastic Package (Z)

Order Number LM285Z-1.2, LM285AZ-1.2, LM285AXZ-1.2, LM285AYZ-1.2,

LM285BXZ-1.2, LM285BYZ-1.2, LM385Z-1.2, LM385AZ-1.2, LM385AXZ-1.2,

LM385AYZ-1.2, LM385BZ-1.2, LM385BXZ-1.2 or LM385BYZ-1.2

NS Package Number Z03A

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failure to perform, when properly used in accordance support device or system, or to affect its safety or

with instructions for use provided in the labeling, can effectiveness.

be reasonably expected to result in a significant injury

to the user.

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