MSP430F149: Power On Reset Problem

seogje cho

Part Number: MSP430F149

Hello,

I have a big issue with MSP430F149 regarding the Power On Reset.
My reset circuit parameter is R:4.7K, C:4.7uF.
After a long period of power-off status, the MCU doesn't work when power is supplied for the first time. But, 2 or 3 seconds later, the MCU works if the power is resupplied.

I would appreciate any comment.

over 1 year ago

+1 Xiaodong LI over 1 year ago

TI__Mastermind 22805 points

Hi Seogje

Please check MSP-TS430PM64 page 98 of MSP430 Hardware Tools User's Guide (Rev. AH)

R should be 47K C should be 10uF and 100nF

Thanks!

0 David Schultz over 1 year ago in reply to Xiaodong LI

Guru 22705 points

The MSP430 does power on reset just fine on its own.

If the _RST_/NMI pin isn't going to be used, it is recommended to use a pullup resistor of 47K to Vcc. A capacitor to ground should be very small, typically 10nF, for compatibility with the JTAG interface.

The 10uF/100nF combo is for Vcc and Vss.

0 seogje cho over 1 year ago in reply to Xiaodong LI

Prodigy 110 points

Hi Xiaodong,
My issue is resolved using your recommendation. I don't have a 10uF/10V capacitor. So, I attached a 22uF/10V capacitor, like the picture below.

Then, the MCU works as I want.
Thanks for your help.

Regards,

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MSP430F149: Power On Reset Problem