INT can be connected to the interrupt input of a 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 I2C bus. Thus, the PCA9534 can remain a simple slave device.
The devices outputs (latched) have high-current drive capability for directly driving LEDs. It has low current consumption.
Three hardware pins (A0, A1, and A2) are used to program and vary the fixed I2C address and allow up to eight devices to share the same I2C bus or SMBus.
The PCA9534 is pin-to-pin and I2C address compatible with the PCF8574. However, software changes are required due to the enhancements in the PCA9534 over the PCF8574.
The PCA9534 is a low-power version of the PCA9554. The only difference between the PCA9534 and PCA9554 is that the PCA9534 eliminates an internal I/O pullup resistor, which dramatically reduces power consumption in the standby mode when the I/Os are held low.
The PCA9534A and PCA9534 are identical, except for their fixed I2C address. This allows for up to 16 of these devices (8 of each) on the same I2C bus.
- Low standby current consumption of 1 µA Max
- I2C to Parallel port expander
- Open-drain active-low interrupt output
- Operating power-supply voltage range of 2.3 V to 5.5 V
- 5-V Tolerant I/O ports
- 400-kHz Fast I2C bus
- Three hardware address pins allow up to eight devices on the I2C/SMBus
- Allows up to 16 devices on the I2C/SMBus when used in conjunction with the PCA9534A See Section 5 for I2C Expander offerings
- Input/output configuration register
- Polarity inversion register
- Internal power-on reset
- Power-up with all channels configured as inputs
- No glitch on power up
- Noise filter on SCL/SDA inputs
- Latched outputs with high-current drive maximum capability for directly driving LEDs
- Latch-up performance exceeds 100 mA Per JESD 78, class II
- ESD Protection exceeds JESD 22
- 2000-V Human-body model (A114-A)
- 200-V Machine model (A115-A)
- 1000-V Charged-device Model (C101)