Low Standby-Current Consumption of 1 µA MaxI2C to Parallel Port ExpanderOpen-Drain Active-Low Interrupt OutputActive-Low Reset Input5-V Tolerant I/O PortsCompatible With Most Microcontrollers400-kHz Fast I2C BusPolarity Inversion RegisterAddress by Two Hardware Address Pinsfor Use of up to Four DevicesLatched Outputs With High-Current Drive Capability for Directly Driving LEDsLatch-Up Performance Exceeds 100 mA Per JESD 78, Class IIESD Protection Exceeds JESD 222000-V Human-Body Model (A114-A)1000-V Charged-Device Model (C101) DESCRIPTION/ORDERING INFORMATION This 16-bit I/O expander for the two-line bidirectional bus (I2C) is designed for 2.3-V to 5.5-V 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 PCA9539 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. All registers can be read by the system master. The system master can reset the PCA9539 in the event of a timeout or other improper operation by asserting a low in the RESET