MSP430FR2111: Connecting capacitor to GPIO

U-SK

Hello,

I would like to connect capacitor so that it is not affected by high frequency noise.

However, if even one capacitor is connected to GPIO, the power of MSP430 will be turned off at the moment when the GPIO becomes High.

Is there a problem connecting the pull-down capacitor to the GPIO?

What are the possible causes?

Regards,

U-SK

over 4 years ago

+1 Keith Barkley over 4 years ago

Guru 42875 points

Probably the turn-on current inrush. You probably need a current limiting resistor.

0 U-SK over 4 years ago in reply to Keith Barkley

Genius 5840 points

Hi Keith,

Thank you for your reply.

I haven't had this problem since I connected the resistor to the GPIO.

By the way, how much inrush current can this device tolerate?

Regards,

U-SK

+1 JD Crutchfield over 4 years ago in reply to U-SK

TI__Mastermind 29795 points

Hello u-SK,

The Digital output pin characteristics are specified here. Anything more than a few mA will cause the GPIO voltage to drop significantly. You might also have to watch the VCC signal itself and the power source to the MSP430, which could both potentially pulled low due to very fast/large inrush current.

Thanks,

+1 zrno soli over 4 years ago in reply to U-SK

Guru 34843 points

U-SK,

MSP430 devices are with fast non configurable pin slew rate. Best option is to connect VCC and pin output (two channels) on scope and see what is going on when output is switching. And than tune it with right resistor value on pin.

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MSP430FR2111: Connecting capacitor to GPIO