MCF8315D: How to handle if SPEED and FG are unused and use I2C at MCF8315..

Ernest Cho

Expert 3311 points

Part Number: MCF8315D

Hi team,

Customer wants to use I2C commands to give speed command and get speed from register.

And they are asking how to do with SPEED and FG if they are not want to use it. (And also they are lack of IO ports.)

I assume FG(OD output) need to be pull up, and speed could connected to GND.

Would you give your feedback?

Bests,
Ernest

1 month ago

+1 Venkatadri Shantaram84961 1 month ago

TI__Mastermind 27447 points

Hi Ernest,

The FG pin can be left floating. For the Speed pin, if customers do not wish to use sleep mode, they can connect it to ground. Please refer to the sleep/standby entry and exit criteria for more details.

Thanks and Best regards

Venkatadri S

0 Ernest Cho 1 month ago in reply to Venkatadri Shantaram84961

TI__Expert 3311 points

Hi Venkatadri,

Yes, I already saw this.

Customer just wanted to have the switch for the MCF8315D VCC(24V) line.

Thanks.
Ernest

0 Venkatadri Shantaram84961 1 month ago in reply to Ernest Cho

TI__Mastermind 27447 points

Hi Ernest,

Can you elaborate about the use case?

Thanks and Best regards

Venkatadri S

0 Ernest Cho 1 month ago in reply to Venkatadri Shantaram84961

TI__Expert 3311 points

Hi Venkat,

I meant customer do not use sleep mode and they will use a power switch in the 24V rail and will turn it on and off the device. And so they may connect to the GND for SPEED pin, floating the pin for FG.

Thanks,

Ernest

0 Venkatadri Shantaram84961 1 month ago in reply to Ernest Cho

TI__Mastermind 27447 points

Hi Ernest,

Got it, thanks for clarification.

Thanks and Best regards

Venkatadri S

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MCF8315D: How to handle if SPEED and FG are unused and use I2C at MCF8315..