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

8.2.1.1 Minimizing ICC When I/Os Control Leds

When the I/Os are used to control LEDs, normally they are connected to VCC through a resistor as shown in Figure 8-1. The LED acts as a diode, so when the LED is off, the I/O VIN is about 1.2 V less than VCC. ICC in Electrical Characteristics shows how ICC increases as VIN becomes lower than VCC.

For battery-powered applications, it is essential that the voltage of I/O pins is greater than or equal to VCC when the LED is off to minimize current consumption. Figure 8-2 shows a high-value resistor in parallel with the LED. Figure 8-3 shows VCC less than the LED supply voltage by at least 1.2 V. Both of these methods maintain the I/O VIN at or above VCC and prevents additional supply current consumption when the LED is off.

GUID-A9D2C6A4-E054-4F7A-82BC-1D25E9FBC83F-low.gifFigure 8-2 High-Value Resistor in Parallel with Led
GUID-EF113FF1-4265-4076-AF5D-9F7F9CA06C2B-low.gifFigure 8-3 Device Supplied by a Lower Voltage