SCPS254D January   2014  – October 2021 TCA9539-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 I2C Interface Timing Requirements
    7. 6.7 RESET Timing Requirements
    8. 6.8 Switching Characteristics
    9. 6.9 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 I/O Port
      2. 8.3.2 RESET Input
      3. 8.3.3 Interrupt ( INT) Output
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power-On Reset
    5. 8.5 Programming
      1. 8.5.1 I2C Interface
    6. 8.6 Register Maps
      1. 8.6.1 Device Address
      2. 8.6.2 Control Register And Command Byte
      3. 8.6.3 Register Descriptions
        1. 8.6.3.1 Bus Transactions
          1. 8.6.3.1.1 Writes
          2. 8.6.3.1.2 Reads
  9. 9 Power Supply Recommendations
    1. 9.1 Power-On Reset Requirements
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary

Package Options

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

8.1 Overview

The TCA9539-Q1 is a 16-bit I/O expander for the two-line bidirectional bus (I2C) designed for 1.65 V to 3.6 V, VCC operation. It provides general-purpose remote I/O expansion for most microcontroller families via the I2C interface, serial clock (SCL) and serial data (SDA).

The TCA9539-Q1 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 controller can enable the I/Os as either inputs or outputs by writing to the configuration register 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 controller.

The system controller can reset the TCA9539-Q1 in the event of a time-out 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. Asserting RESET causes the same reset-initialization to occur without depowering the part.

The TCA9539-Q1 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 controller 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 TCA9539-Q1 can remain a simple target device.

The TCA9539-Q1 is similar to the TCA9555, except for the removal of the internal I/O pull-up resistor, which greatly reduces power consumption when the I/Os are held low, replacement of A2 with RESET, and a different address range. The TCA9539-Q1 is similar to the PCA9539 with lower voltage support (down to VCC = 1.65 V), and also improved power-on reset circuitry for different application scenarios.

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.