Datasheet

PCA9570 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2014. All rights reserved.
Product data sheet Rev. 4 — 17 September 2014 10 of 32
NXP Semiconductors
PCA9570
Remote 4-bit general purpose outputs for 1 MHz I
2
C-bus
9. Application design-in information
9.1 I/O expander applications
Figure 14 shows a 4-bit output expander application. The desired HIGH or LOW logic
levels are controlled by the master with speeds of up to 1 MHz on a lightly loaded bus
(<100 pF). This allows the host processor to control various functions quickly and with
very low overhead. The port read function of the device enables the host processor to poll
the status of the output port pins. This is useful for system recovery operations or
debugging.
Fig 14. I/O expander application
002aah232
latch control
switch control
P0
P1
P2
P3
1.8 V
SDA
SCL
CORE
PROCESSOR
1.8 V
GPS enable
vibrator control