LM199/LM299/LM399
Precision Reference
General Description
The LM199 series are precision, temperature-stabilized
monolithic zeners offering temperature coefficients a factor
of ten better than high quality reference zeners. Constructed
on a single monolithic chip is a temperature stabilizer circuit
and an active reference zener. The active circuitry reduces
the dynamic impedance of the zener to about 0.5Ω and
allows the zener to operate over 0.5 mA to 10 mA current
range with essentially no change in voltage or temperature
coefficient. Further, a new subsurface zener structure gives
low noise and excellent long term stability compared to
ordinary monolithic zeners. The package is supplied with a
thermal shield to minimize heater power and improve temperature regulation.
The LM199 series references are exceptionally easy to use
and free of the problems that are often experienced with
ordinary zeners. There is virtually no hysteresis in reference
voltage with temperature cycling. Also, the LM199 is free of
voltage shifts due to stress on the leads. Finally, since the
unit is temperature stabilized, warm up time is fast.
The LM199 can be used in almost any application in place of
ordinary zeners with improved performance. Some ideal
applications are analog to digital converters, calibration standards, precision voltage or current sources or precision
power supplies. Further in many cases the LM199 can replace references in existing equipment with a minimum of
wiring changes.
The LM199 series devices are packaged in a standard hermetic TO-46 package inside a thermal shield. The LM199 is
rated for operation from −55˚C to +125˚C while the LM299 is
rated for operation from −25˚C to +85˚C and the LM399 is
rated from 0˚C to +70˚C.
Features
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Guaranteed 0.0001%/˚C temperature coefficient
Low dynamic impedance — 0.5Ω
Initial tolerance on breakdown voltage — 2%
Sharp breakdown at 400 µA
Wide operating current — 500 µA to 10 mA
Wide supply range for temperature stabilizer
Guaranteed low noise
Low power for stabilization — 300 mW at 25˚C
Proven reliability, low-stress packaging in TO-46
integrated-circuit hermetic package, for low hysteresis
after thermal cycling. 33 million hours MTBF at TA =
+25˚C (TJ = +86˚C)
Connection Diagram
Metal Can Package (TO-46)
00571714
Top View
NS Package Number H04D
Ordering Information
Order Number
Initial Tolerance
Ambient Temperature
LM199AH
± 2%
± 2%
± 2%
± 5%
± 5%
LM199AH/883
LM299H
LM399AH
LM399H
© 2005 National Semiconductor Corporation
Package Marking
Transport Method
-50˚C to +125˚C
LM199AH
Box of 500
H04A
-50˚C to +125˚C
LM199AH/Q
Tray of 20
H04A
-25˚C to +85˚C
LM299H
Box of 500
H04A
0˚C to +70˚C
LM399AH
Box of 500
H04A
0˚C to +70˚C
LM399H
Box of 500
H04A
DS005717
NSC Package
www.national.com
LM199/LM299/LM399 Precision Reference
April 2005
