topic PCA9555 Power on or reset condition in Other NXP Products

PCA9555 Power on or reset condition

meet — Tue, 30 Jan 2024 12:23:34 GMT

Currently I am using Texas Instruments PCF8575 IC of IO expander. With this IC , I am facing issue of all pins are high at power on or reset condition. But I require all pins are low at power on or reset condition. Should I use NXP PCA9555 IC for resolve this issue? From datasheet of NXP PCA9555 IC, At
reset, the device's ports are inputs with a pull-up to VDD. (In Output we get input pin low voltage or high voltage?)

If I don't resolve this issue using NXP PCA9555 IC then which IC should I use for resolve this issue ?

Re: PCA9555 Power on or reset condition

diazmarin09 — Tue, 30 Jan 2024 18:56:01 GMT

Hello meet,

I hope all is great with you. Thank you for using the NXP communities.

You are correct, after a valid PCA9555 power-on event, the I/O pins are configured as an inputs. I mean, there will be no logic state at the pin as they are configured as inputs.

Is that what you are looking for?

I hope this information helps.

Regards,

David

Re: PCA9555 Power on or reset condition

meet — Fri, 16 Feb 2024 06:41:50 GMT

i connect io expander IO (PCF8575) pin connect tps7a8300rgwt Enable pin and adp7104rdz Enable Pin. and PCF8575 I2C channel connect to ARTY A7 FPGA.

At Power On FPGA config Some Time(2-3 sec) with Flash and this time IO expander Pin On and All TPS and ADP power supply Generate.

and i also Try NXP PCA9555 Ic this IC reset condition or power On all Pin are input but output voltage available. NXP PCA9555 Ic datasheet write At reset, the device's ports are inputs with a pull-up to VDD.
NXP PCA9555 not Resolved My problem.
plz suggest other io expander

Re: PCA9555 Power on or reset condition

diazmarin09 — Fri, 16 Feb 2024 17:52:35 GMT

Hello meet,

I am pleased to contact you again.

I am afraid that, within our I/O expander portfolio, the I/O pins are configured as high-impedance input by default.

Please accept my apologies.

Regards,

David