The PCA9555DB is a 16-bit I/O Expander for the two-line bidirectional bus (I2C) is designed for 2.3 to 5.5V VCC operation. It provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface [serial clock (SCL), serial data (SDA)]. The PCA9555 consists of two 8-bit configuration (input or output selection), input port, output port and polarity inversion (active high or active low operation) registers. At power on, the I/Os are configured as inputs. The system master can enable the I/Os as either inputs or outputs by writing to the I/O configuration bits. The data for each input or output is kept in the corresponding Input or Output register. The polarity of the input port register can be inverted with the Polarity Inversion register. The device outputs (latched) have high-current drive capability for directly driving LEDs. All registers can be read by the system master.
Open-drain active-low interrupt (INT)\ output
Compatible with most microcontrollers
400kHz Fast I2C bus
Address by 3 hardware address pins for use of up to 8 devices
Polarity inversion register
Latched outputs with high-current drive capability for directly driving LEDs
