PCA9538PWR 5.5 V UART Interface IC I/O Expanders Rem 8B I2C & SMBus Lo-Pwr I/O Expander

PCA9538PWR UART Interface IC I/O Expanders Rem 8B I2C & SMBus Lo-Pwr I/O Expander

1 Features

• Low Standby Current Consumption of 1 μA Max

• I2C to Parallel Port Expander

• Open-Drain Active-Low Interrupt Output

• Active-Low Reset Input

• Operating Power-Supply Voltage Range of 2.3 V to5.5V

• 5-V Tolerant I/O Ports

• 400-kHz Fast I2C Bus

• 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 Inputs

• Latched Outputs With High-Current Drive Maximum Capability for Directly Driving LEDs

• Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II

• ESD Protection Exceeds JESD 22

2 Description

This 8-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 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. The power-on reset puts the registers in their default state and initializes the I2C/SMBus state machine. The RESET pin causes the same reset/initialization to occur without powering down the part.

The PCA9538 open-drain interrupt (INT) output is activated when any input state differs from its corresponding Input Port register state and is used to indicate to the system master that an input state has changed.

Device Information