LM285BXZ-2.5 - National Semiconductor

TL/H/5519

LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode

December 1994

LM185-2.5/LM285-2.5/LM385-2.5 Micropower

Voltage Reference Diode

General Description

The LM185-2.5/LM285-2.5/LM385-2.5 are micropower 2-

terminal band-gap voltage regulator diodes. Operating over

a20mA to 20 mA current range, they feature exceptionally

low dynamic impedance and good temperature stability. On-

chip trimming is used to provide tight voltage tolerance.

Since the LM-185-2.5 band-gap reference uses only transis-

tors and resistors, low noise and good long term stability

result.

Careful design of the LM185-2.5 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 LM185-2.5 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. For applications re-

quiring 1.2V see LM185-1.2.

The LM185-2.5 is rated for operation over a b55§Cto

125§C temperature range while the LM285-2.5 is rated

b40§Cto85

C and the LM385-2.5 0§Cto70

C. The LM185-

2.5/LM285-2.5 are available in a hermetic TO-46 package

and the LM285-2.5/LM385-2.5 are also available in a low-

cost TO-92 molded package, as well as S.O. The LM185-25

is also available in a hermetic leadless chip carrier package.

Features

Yg20 mV (g0.8%) max. initial tolerance (A grade)

YOperating current of 20 mAto20mA

Y0.6Xdynamic impedance (A grade)

YLow temperature coefficient

YLow voltage referenceÐ2.5V

Y1.2V device and adjustable device also availableÐ

LM185-1.2 series and LM185 series, respectively

Applications

Wide Input Range Reference

TL/H/5519–12

Micropower Reference from 9V Battery

TL/H/5519–2

Connection Diagrams

TO-92

Plastic Package

TL/H/5519–8

Bottom View

Order Number LM285Z-2.5,

LM285AZ-2.5, LM285AXZ-2.5,

LM285AYZ-2.5,

LM285BXZ-2.5, LM285BYZ-2.5,

LM385Z-2.5, LM385AZ-2.5,

LM385AXZ-2.5, LM385AYZ-2.5,

LM385BZ-2.5, LM385BXZ-2.5

or LM385BYZ-2.5

See NS Package Number Z03A

TO-46

Metal Can Package

TL/H/5519–13

Bottom View

Order Number LM185H-2.5,

LM185H-2.5/883

LM185BXH-2.5, LM185BXH-2.5/883,

LM185BYH-2.5, LM185BYH2.5/883,

LM285H-2.5, LM285BXH-2.5

or LM285BYH-2.5

See NS Package Number H02A

SO Package

TL/H/5519–11

Order Number LM285M-2.5,

LM285AM-2.5, LM285AXM-2.5,

LM285AYM-2.5, LM285BXM-2.5,

LM285BYM-2.5, LM385M-2.5,

LM385AM-2.5, LM385AXM-2.5,

LM385AYM-2.5, LM385BM-2.5,

LM385BXM-2.5 or LM385BYM-2.5

See NS Package Number M08A

C1995 National Semiconductor Corporation RRD-B30M75/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)

LM185-2.5 b55§Ctoa125§C

LM285-2.5 b40§Ctoa85§C

LM385-2.5 0§Cto70

Storage Temperature b55§Ctoa150§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 Typ

LM285A-2.5 LM385A-2.5

(Limits)

Units

LM285AX-2.5 LM385AX-2.5

LM285AY-2.5 LM385AY-2.5

Tested Design Tested Design

Limit Limit Limit Limit

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

Reverse Breakdown IRe100 mA 2.500 2.480 2.480 V(Min)

Voltage 2.520 2.520 V(Max)

2.500 2.460 2.470 V(Min)

2.535 2.530 V(Max)

Minimum Operating 12 18 20 18 20 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, 0.2 0.6 0.6 X

Impedance f e20 Hz 1.5 1.5

Wideband Noise (rms) IRe100 mA120 mV

10 Hz sfs10 kHz

Long Term Stability IRe100 mA,

Te1000 Hr, 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)

LM185-2.5

LM185BX-2.5 LM385B-2.5

LM185BY-2.5 LM385BX-2.5 LM385-2.5 Units

LM285-2.5 LM385BY-2.5 (Limit)

Parameter Conditions Typ LM285BX-2.5

LM285BY-2.5

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, 2.5 2.462 2.462 2.425 V(Min)

Voltage 20 mAsIRs20 mA 2.538 2.538 2.575 V(Max)

Minimum Operating 13 20 30 20 30 20 30 mA

Current (Max)

Reverse Breakdown 20 mAsIRs1mA 1 1.5 2.0 2.5 2.0 2.5 mV

Voltage Change with (Max)

Current 1mAsI

Rs20 mA 10 20 20 25 20 25 mV

(Max)

Reverse Dynamic IRe100 mA, 1X

Impedance f e20 Hz

Wideband Noise (rms) IRe100 mA, 120 mV

10 Hz sfs10 kHz

Long Term Stability IRe100 mA,

Te1000 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-2.5 for military specifications.

Note 3: For elevated temperature operation, TJ MAX 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)

ija (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–TMIN. 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 available on request.

Typical Performance Characteristics

Reverse Characteristics Reverse Characteristics Forward Characteristics

Temperature Drift Impedance

Reverse Dynamic

Impedance

Reverse Dynamic

Noise Voltage Filtered Output Noise Response Time

TL/H/5519–3

Connection Diagram

TL/H/5519–14

Order Number LM185E-2.5/883

See NS Package Number E20A

LM385-2.5 Applications

Micropower*5V Regulator

*IQj40 mATL/H/5519–9

Micropower*10V Reference

TL/H/5519–10

*IQj30 mA standby current

Precision 1 mA to 1 mA Current Sources

TL/H/5519–4

*IOUT e2.5V

METER THERMOMETERS

0§C–100§C Thermometer 0§F–50§F Thermometer

TL/H/5519–5

Calibration

1. Short LM385-2.5, adjust R3 for IOUTetemp at 1mA/§K

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

Calibration

1. Short LM385-2.5, adjust R3 for IOUTetemp at 1.8 mA/§K

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

LM385-2.5 Applications (Continued)

Micropower Thermocouple Cold Junction Compensator

TL/H/5519–6

Adjustment 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.

Seebeck Voltage Voltage

Thermocouple Co- R1 R2 Across R1 Across R2

Type efficient (X)(X)@

25§C(mV)

(mV/§C) (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

Improving Regulation of Adjustable

Regulators

TL/H/5519–7

Schematic Diagram

TL/H/5519–1

Physical Dimensions inches (millimeters)

Order Number LM185E-2.5/883

NS Package Number E20A

Physical Dimensions inches (millimeters) (Continued)

TO-46 Metal Can Package (H)

Order Number LM185H-2.5, LM185H-2.5/883, LM185BXH-2.5, LM185BXH-2.5/883,

LM185BYH-2.5, LM185BYH-2.5/883, LM285H-2.5, LM285BXH-2.5 or LM285BYH-2.5

NS Package Number H02A

Physical Dimensions inches (millimeters) (Continued)

Small Outline (SO-8) Package (M)

Order Number LM285M-2.5, LM285AM-2.5, LM285AXM-2.5, LM285AYM-2.5,

LM285BXM-2.5, LM285BYM-2.5, LM385M-2.5, LM385AM-2.5, LM385AXM-2.5,

LM385AYM-2.5, LM385BM-2.5, LM385BXM-2.5 or LM385BYM-2.5

NS Package Number M08A

LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode

Physical Dimensions inches (millimeters) (Continued)

TO-92 Plastic Package (Z)

Order Number LM285Z-2.5, LM285AZ-2.5, LM285AXZ-2.5, LM285AYZ-2.5,

LM285BXZ-2.5, LM285BYZ-2.5, LM385Z-2.5, LM385AZ-2.5, LM385AXZ-2.5,

LM385AYZ-2.5, LM385BZ-2.5, LM385BXZ-2.5 or LM385BYZ-2.5

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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