ADS1247: RESET pin function

Taketo Sato

Genius 9465 points

Part Number: ADS1247

Hello team,

I have a quick question about ADS1247 RESET pin pulse.

Datasheet says at least 4tclk is required for RESET pin low duration to reset device by RESET pin.

Could you please let me know whether reset is performed or not when RESET pin low duration is shorter than 4tclk?

I would like to know it to confirm if the device could be reset when noise is applied to RESET pin line.

Best regards,

over 5 years ago

0 Alexander Smith over 5 years ago

TI__Mastermind 47595 points

Hello Sato-san,

Thanks for your post!

Since the minimum duration is 4tclk, the only way to guarantee that a reset is performed is if the pin is held low for at least 4tclk. The device should not reset if the pin is held low for less than 4tclk.

0 Taketo Sato over 5 years ago in reply to Alexander Smith

TI__Genius 9465 points

Hello Alex-san,

Thanks for prompt reply.
I understand the device shouldn't perform reset if the pin is held low for less than 4tclk, like a noise event on RESET pin.
Customer is seeing some register settings somehow get back to reset values and suspected it is due to noise on RESET pin. I will confirm SPI timing requirement is proper.

Best regards,

0 Alexander Smith over 5 years ago in reply to Taketo Sato

TI__Mastermind 47595 points

Hello Sato-san,

I am happy to help!

Another thing to check for is noise on the GND - especially during transient or ESD events. If the GND level shifts past a certain point it can cause the device to RESET.

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ADS1247: RESET pin function