1. General description
The PCA9671 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
(Fm+) family.
The PCA9671 is a drop in upgrade for the PCF8575 providing higher 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) to allow many more devices on the bus without address conflicts.
The difference between the PCA9671 and the PCF8575 is that the interrupt output on the
PCF8575 is replaced by a RESET
input on the PCA9671.
The device consists of a 16-bit quasi-bidirectional port and an I
2
C-bus interface. The
PCA9671 has a low current consumption and includes latched outputs with 25 mA high
current drive capability for directly driving LEDs. The internal Power-On Reset (POR),
hardware reset pin (RESET
) 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-mode and Standard-mode
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 reset input
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
Packages offered: SO24, TSSOP24, HVQFN24, DHVQFN24
PCA9671
Remote 16-bit I/O expander for Fm+ I
2
C-bus with reset
Rev. 3 — 29 September 2011 Product data sheet
