NXP Semiconductors
4. Block diagram
PCA9554; PCA9554A
8-bit I2C-bus and SMBus I/O port with interrupt
PCA9554/PCA9554A
A0
A1
A2
SCL
SDA
INPUT
FILTER
VDD
POWER-ON
RESET
VSS
I2C-BUS/SMBus
CONTROL
8-bit
write pulse
read pulse
INPUT/
OUTPUT
PORTS
IO0
IO1
IO2
IO3
IO4
IO5
IO6
IO7
VDD
LP
FILTER
INT
002aac492
All I/Os are set to inputs at reset.
Fig 1. Block diagram of PCA9554/PCA9554A
PCA9554_9554A
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 10 — 8 November 2017
© NXP Semiconductors N.V. 2017. All rights reserved.
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