PCA9536DGKR

This 4-bit expander for the two-wire bidirectional bus (I²C) is designed to operate from 2.3V to 5.5V. Through the I²C interface [Serial Clock (SCL), Serial Data (SDA)], it provides general-purpose remote I/O expansion for most microcontroller families. The PCA9536 contains 4-bit configuration (input or output selectable), input port, output port, and polarity inversion (active-high or active-low) registers. At power-up, the I/Os are configured as weak pull-up inputs to VCC. However, the system controller can enable the I/Os as inputs or outputs by writing to the I/O configuration bits. If no signal is externally applied to the PCA9536, the internal pull-up resistors cause the voltage level to be 1 or high. The data for each input or output is stored in the corresponding input port or output port register. The polarity of the input port register can be inverted using the polarity inversion register, and the system controller reads all registers. In the event of a timeout or other improper operation, the system controller can reset the PCA9536 by using the power-on reset function to place the registers in their default states and initialize the I2C/SMBus state machine. The outputs of this device (which are latched) have high current drive capability to directly drive LEDs, yet achieve low current consumption.