EK-TM4C123GXL: Use of Dual Schottky diode in Tiva C Launchpad

supreeth anil

Part Number: EK-TM4C123GXL

Hello All,

There is a Schottky diode connected to the RESET output of the voltage supervisor in the Tiva C launchpad as shown below

One of the anodes goes to the RESET pin of the main microcontroller and the other one to the RESET pin of the microcontroller used for debugging.

What is the use of a Schottky diode in the output of a voltage supervisor like this?

over 6 years ago

0 Bob Crosby over 6 years ago

TI__Guru 72500 points

How old is your launchpad? The current launchpads (for several years now) omit this circuit.

From the 2013 version of the User's Guide: http://www.ti.com/lit/ug/spmu296/spmu296.pdf

0 supreeth anil over 6 years ago in reply to Bob Crosby

Prodigy 230 points

From TM4C123G6PM datasheet

"The internal Power-On Reset (POR) circuit monitors the power supply voltage (VDD) and generates
a reset signal to all of the internal logic including JTAG when the power supply ramp reaches a
threshold value (VVDD_POK)."

Are we omiting the SVS section because of the inbuilt POR circuitry in Tiva C boards? Does it mean that the older version of stellaris did not have an inbuilt POR circitry?

0 Bob Crosby over 6 years ago in reply to supreeth anil

TI__Guru 72500 points

I honestly don't know. I was not involved with these parts during the development stage. Why do you ask?

0 supreeth anil over 6 years ago in reply to Bob Crosby

Prodigy 230 points

I am trying to build a custom board based on the schematics. So knowing these details will fool proof my design.

0 Bob Crosby over 6 years ago in reply to supreeth anil

TI__Guru 72500 points

You may safely omit that circuit as all TM4C parts now shipping (and for the last several years) do not require it.

Arm-based microcontrollers

Arm-based microcontrollers forum

EK-TM4C123GXL: Use of Dual Schottky diode in Tiva C Launchpad