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LM385-1.2-MIL

SLVSE73 – JUNE 2017

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7 Detailed Description

7.1 Overview

The LM385-1.2-MIL device is micropower, two-terminal, band-gap voltage references which operate over a 10-

μA to 20-mA current range. On-chip trimming provides tight voltage tolerance. The band-gap reference for these

devices has low noise and long-term stability.

The design makes these devices exceptionally tolerant of capacitive loading and, thus, easier to use in most

reference applications. The wide dynamic operating temperature range accommodates varying current supplies,

with excellent regulation.

The extremely low power drain of this series makes them useful for micropower circuitry. These voltage

references can be used to make portable meters, regulators, or general-purpose analog circuitry, with battery life

approaching shelf life.

7.2 Functional Block Diagram

A.

Component values shown are nominal.

7.3 Feature Description

A band gap voltage reference controls high gain amplifier and shunt pass element to maintain a nearly constant

voltage between cathode and anode. Regulation occurs after a minimum current is provided to power the voltage

divider and amplifier. Internal frequency compensation provides a stable loop for all capacitor loads. Floating

shunt design is useful for both positive and negative regulation applications.

7.4 Device Functional Modes

The LM385-1.2-MIL device operates in one mode, which is as a fixed voltage reference that cannot be adjusted.

In order for a proper Reverse Voltage to be developed, current must be sourced into the cathode of LM285. The