The PCA9538PW 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 PCA9538 consists of one 8-bit Configuration (input or output selection), input port, output port and polarity inversion (active high or active low) registers. At power on, the I/Os are configured as inputs. 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 Port or Output Port 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 PCA9538 in the event of a timeout or other improper operation by asserting a low in the RESET input.
Open-drain active-low interrupt (INT)\ output
Active-Low Reset Input
Two hardware address pins allow up to four devices on the I2C/SMBus
Input/output configuration register
Polarity inversion register
Power-up with all channels configured as inputs
No glitch on power-up
Noise filter on SCL/SDA input
Latched outputs with high-current drive maximum capability for directly driving LEDs
Latch-up performance exceeds 100mA per JESD 78, class II
(EN)
