LM185-2.5/LM285-2.5/LM385-2.5 Micropower Voltage Reference Diode
December 1999
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 a 20 µA to 20 mA current range, they feature exception-
ally 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 re-
sult.
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 purpose
analog circuitry with battery life approaching shelf life. Fur-
ther, the wide operating current allows it to replace older ref-
erences with a tighter tolerance part. For applications requir-
ing 1.2V see LM185-1.2.
The LM185-2.5 is rated for operation over a −55˚C to 125˚C
temperature range while the LM285-2.5 is rated −40˚C to
85˚C and the LM385-2.5 0˚C to 70˚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. and SOT-23. The
LM185-2.5 is also available in a hermetic leadless chip car-
rier package.
Features
n
n
n
n
n
n
±
20 mV (
±
0.8%) max. initial tolerance (A grade)
Operating current of 20 µA to 20 mA
0.6Ω dynamic impedance (A grade)
Low temperature coefficient
Low voltage reference — 2.5V
1.2V device and adjustable device also
available — LM185-1.2 series and LM185 series,
respectively
Connection Diagrams
TO-92
Plastic Package
SO Package
DS005519-8
Bottom View
Order Number LM285Z-2.5,
LM285BXZ-2.5, LM285BYZ-2.5
LM385Z-2.5, LM385AXZ-2.5
LM385AYZ-2.5, LM385BZ-2.5,
LM385BXZ-2.5 or LM385BYZ-2.5
See NS Package Number Z03A
DS005519-11
Order Number LM285M-2.5,
LM285BXM-2.5, LM285BYM-2.5
LM385M-2.5, LM385BM-2.5
LM385BXM-2.5 or LM385BYM-2.5
See NS Package Number M08A
SOT-23
DS005519-29
*
Pin 3 is attached to the Die Attach Pad (DAP) and should be connected to Pin 2 or left floating.
Order Number LM385M3-2.5
See NS Package Number MA03B
© 1999 National Semiconductor Corporation
DS005519
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
