PCA9539: /RESET Pin Behavior

Sadanori Kato

Part Number: PCA9539

Hi,

The power-on reset errata is mentioned on page 29 of PCA9539 data sheet. So, are all internal state machines forced to defaults regardless of the power-on sequence if /RESET is asserted to low during the power-on and /RESET is de-asserted to high when the power supply voltage VCC is stable?

Or, should /RESET de-asserted twice as follows?

Best regards,
Kato

over 5 years ago

0 Miguel Robertson over 5 years ago

TI__Guru 62920 points

Kato-san,

It is effective to hold /RESET low and then de-assert it after VCC has stabilized as shown in your first diagram. It is not necessary to de-assert /RESET twice.

Regards,
Max

0 Sadanori Kato over 5 years ago in reply to Miguel Robertson

Guru 36540 points

Hi Max-san,

Thank you for the information.

I understand.

Best regards,
Kato

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PCA9539: /RESET Pin Behavior