The PCA9554DB is an 8-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 PCA9554 consists of one 8-bit configuration (input or output selection), input, output and polarity inversion (active high or active low) registers. At power on, the I/Os are configured as inputs with a weak pull-up to VCC. However, 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. All registers can be read by the system master. The system master can reset the PCA9554 in the event of a timeout or other improper operation by utilizing the power-on reset feature.
● Open-drain active-low interrupt (INT)\ output
● 400kHz Fast I²C bus
● Three hardware address pins allow up to eight devices on the I²C/SMBus
● Input/output configuration register
● Polarity inversion register
● Power-up with all channels configured as inputs
● Internal power-ON reset
● No glitch on power-up
● Latched outputs with high-current drive maximum capability for directly driving LEDs
● Latch-up performance exceeds 100mA per JESD 78, class II
● Green product and no Sb/Br
●Device has limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
