SCPS126G September   2006  – March 2021 PCA9538

PRODUCTION DATA  

  1. 1 Features
  2. 2 Description
  3. 3 Revision History
  4. 4 Pin Configuration and Functions
  5. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 I2C Interface Timing Requirements
    7. 5.7 RESET Timing Requirements
    8. 5.8 Switching Characteristics
    9. 5.9 Typical Characteristics
  6. 6 Parameter Measurement Information
  7. 7 Detailed Description
    1. 7.1 Functional Block Diagram
    2. 7.2 Device Functional Modes
      1. 7.2.1 RESET Input
        1. 7.2.1.1 RESET Errata
          1.        System Impact
          2.        System Workaround
      2. 7.2.2 Power-On Reset
      3. 7.2.3 I/O Port
      4. 7.2.4 Interrupt Output ( INT)
        1. 7.2.4.1 Interrupt Errata
          1.        System Impact
          2.        System Workaround
    3. 7.3 Programming
      1. 7.3.1 I2C Interface
    4. 7.4 Register Maps
      1. 7.4.1 Device Address
      2. 7.4.2 Control Register And Command Byte
      3. 7.4.3 Register Descriptions
      4. 7.4.4 Bus Transactions
        1. 7.4.4.1 Writes
        2. 7.4.4.2 Reads
  8. 8 Application Information Disclaimer
    1. 8.1 Application Information Disclaimer
    2. 8.2 Typical Application
      1. 8.2.1 Detailed Design Procedure
        1. 8.2.1.1 Minimizing ICC When I/Os Control Leds
  9. 9 Power Supply Recommendations
    1. 9.1 Power-On Reset Requirements
  10. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  11. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

2 Description

The PCA9538 is an 8-bit I/O expander of general purpose parallel input and output (I/O) expansion for the two-line bidirectional I2C bus (or SMBus) protocol. This device can operate with a power supply range from 2.3 V to 5.5 V. This device supports both
100-kHz (Standard-mode) and 400-kHz (Fast-mode) clock frequencies. This device, along with other I/O expanders, provides a simple solution when additional I/Os are needed for switches, sensors, push-buttons, LEDs, fans, and so on.

The features of PCA9538 include an interrupt that is generated on the INT pin whenever an input port changes state. The A0 and A1 hardware selectable address pins allow up to four PCA9538 devices on the same I2C bus. This device can also be reset to its default state by using the RESET feature or by cycling the power supply to cause a power-on reset.

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 PCA9538 can remain a simple slave device.

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

Two hardware pins (A0 and A1) are used to program and vary the fixed I2C address and allow up to four devices to share the same I2C bus or SMBus.

Device Information
PART NUMBER PACKAGE(1) BODY SIZE (NOM)
PCA9538 SSOP (16) 6.20 mm × 5.30 mm
TVSOP (16) 3.60 mm × 4.40 mm
SOIC (16) 10.30 mm × 7.50 mm
TSSOP (16) 5.00 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at the end of the datasheet.
GUID-2F196EE9-4C92-4B8B-B65C-6BEEFCFAD7E7-low.gif Block Diagram