1. General description
The PCA9675 provides general purpose remote I/O expansion for most microcontroller
families via the two-line bidirectional bus (I
2
C-bus) and is a part of the Fast-mode Plus
family.
The PCA9675 is a drop in upgrade for the PCF8575 providing higher Fast-mode Plus
(Fm+) I
2
C-bus speeds (1 MHz versus 400 kHz) so that the output can support PWM
dimming of LEDs, higher I
2
C-bus drive (30 mA versus 3 mA) so that many more devices
can be on the bus without the need for bus buffers, higher total package sink capacity
(400 mA versus 100 mA) that supports having all 25 mA LEDs on at the same time and
more device addresses (64 versus 8) are available to allow many more devices on the
bus without address conflicts.
The device consists of a 16-bit quasi-bidirectional port and an I
2
C-bus interface. The
PCA9675 has a low current consumption and includes latched outputs with high current
drive capability for directly driving LEDs.
It also possesses an interrupt line (INT
) which can be connected to the interrupt logic of
the microcontroller. By sending an interrupt signal on this line, the remote I/O can inform
the microcontroller if there is incoming data on its ports without having to communicate via
the I
2
C-bus. The internal Power-On Reset (POR) or software reset sequence initializes
the I/Os as inputs.
2. Features and benefits
1MHz I
2
C-bus interface
Compliant with the I
2
C-bus Fast and Standard modes
SDA with 30 mA sink capability for 4000 pF buses
2.3 V to 5.5 V operation with 5.5 V tolerant I/Os
16-bit remote I/O pins that default to inputs at power-up
Latched outputs with 25 mA sink capability for directly driving LEDs
Total package sink capability of 400 mA
Active LOW open-drain interrupt output
64 programmable slave addresses using 3 address pins
Readable device ID (manufacturer, device type, and revision)
Low standby current
40 C to +85 C operation
ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per
JESD22-C101
Latch-up testing is done to JEDEC standard JESD78 which exceeds 100 mA
PCA9675
Remote 16-bit I/O expander for Fm+ I
2
C-bus with interrupt
Rev. 2 — 3 October 2011 Product data sheet
