Texas PCA9555DBQR Remote 16-bit I²C and SMBus I/O Expander

Description for the PCA9555

PCA9555DBQR

PCA9555 Series

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 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. All registers can be read by the system master.

Block Diagram

Overview

The system master can reset the PCA9555 in the event of a timeout or other improper operation by utilizing the power-on reset feature, which puts the registers in their default state and initializes the I2C/SMBus state machine.

The PCA9555 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.

INT can be connected to the interrupt input of a microcontroller. By sending an interrupt signal on this line, the remote I/O can inform the microcontroller if there is incoming data on its ports without having to communicate via the I2C bus. Thus, the PCA9555 can remain a simple slave device.

The device outputs (latched) have high-current drive capability for directly driving LEDs.

Logic Diagram

Applications

Servers

• Routers (Telecom Switching Equipment)

• Personal Computers

• Personal Electronics

• Industrial Automation Equipment

• Products with GPIO-Limited Processors

Features for the PCA9555

Low Standby-Current Consumption of 1 µA Max

I²C to Parallel Port Expander

Open-Drain Active-Low Interrupt Output

5-V Tolerant I/O Ports

Compatible With Most Microcontrollers

400-kHz Fast I²C Bus

Address by Three Hardware Address Pins for Use of up to Eight Devices

Polarity Inversion Register

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

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

ESD Protection Exceeds JESD 22

2000-V Human-Body Model (A114-A)

200-V Machine Model (A115-A)

1000-V Charged-Device Model (C101)

PCA9555DBQR Product Parameter

Manufacturer

Texas Instruments is a semiconductor multinational company in Texas, USA. It is famous for developing, manufacturing, and selling semiconductor and computer technology. It is mainly engaged in innovative digital signal processing and analog circuits. In addition to the semiconductor business, it also provides solutions including sensing and control, educational products and digital light source processing. Texas Instruments (TI) is headquartered in Dallas, Texas, USA, and has manufacturing, design or sales organizations in more than 25 countries.