9 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification, and TI

does not warrant its accuracy or completeness. TI’s customers are responsible for determining

suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

9.1 Application Information

The TPS3809xxx-Q1 voltage supervisor device design asserts an active-low RESET signal when VDD drops

below a voltage threshold VIT. The RESET signal remains low until the voltage returns above its threshold. The

typical application is with a processor or microcontroller, which needs to be reset when the supply rail drops

below a specified tolerance.

9.2 Typical Application

3.3 V

TPS3809K33-Q1

TMS320LC54x

GND

GND

RESET

RESET

V DD

V DD

TPS76333

GND

OUT

IN

5 V

Figure 9-1. Typical Application Schematic

9.2.1 Design Requirements

Each device has a fixed=voltage monitoring threshold, and the device should be chosen based on the voltage

being monitored. Refer to Section 5 to determine the VDD voltage threshold for each device. In this example, a

3.3V supply rail to a microcontroller will be monitored.

9.2.2 Detailed Design Procedure

Because a 3.3-V supply rail needs to be monitored, TPS3809K33-Q1 should be used. This device has a 2.93-V

threshold for reset. Connect the 3.3-V supply to the VDD pin and the reset output of the supervisor to the reset

pin of the microcontroller.

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TPS3809J25-Q1, TPS3809L30-Q1, TPS3809K33-Q1, TPS3809I50-Q1

SGLS142C – DECEMBER 2002 – REVISED DECEMBER 2020

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