_

+

LP3470

V

REF

DELAY

R

A

R

B

Q

A

GND

Reset

SRT

V

CC

V

CC1

Copyright © 2016, Texas Instruments Incorporated

8

LP3470

SNVS003G – JUNE 1999 – REVISED APRIL 2016

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Copyright © 1999–2016, Texas Instruments Incorporated

7 Detailed Description

7.1 Overview

The LP3470 micropower voltage supervisory circuit provides a simple solution to monitor the power supplies in

microprocessor and digital systems and provides a reset controlled by the factory-programmed reset threshold

threshold voltage. The reset threshold options are 2.63 V, 2.93 V, 3.08 V, 3.65 V, 4 V, 4.38 V, 4.63 V.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Reset Time-Out Period

calculated using Equation 1.

(1)

the pin SRT must be left floating.

7.3.2 Reset Output

In applications like microprocessor (µP) systems, errors might occur in system operation during power up, power

down, or brownout conditions. It is imperative to monitor the power supply voltage to prevent these errors from

occurring.

brownout condition occurs (monitored voltage falls below the reset threshold minus a small hysteresis), Reset

logic high. Figure 9 shows this behavior.