SLDS274A September   2024  – March 2025 DRV81242-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 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 SPI Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Control Pins
        1. 7.3.1.1 Input Pins
        2. 7.3.1.2 nSLEEP Pin
      2. 7.3.2 Power Supply
        1. 7.3.2.1 Modes of Operation
          1. 7.3.2.1.1 Power-up
          2. 7.3.2.1.2 Sleep mode
          3. 7.3.2.1.3 Idle mode
          4. 7.3.2.1.4 Active Mode
          5. 7.3.2.1.5 Limp Home Mode
        2. 7.3.2.2 Reset condition
      3. 7.3.3 Power Stage
        1. 7.3.3.1 Switching Resistive Loads
        2. 7.3.3.2 Inductive Output Clamp
        3. 7.3.3.3 Maximum Load Inductance
        4. 7.3.3.4 Reverse Current Behavior
        5. 7.3.3.5 Switching Channels in parallel
        6. 7.3.3.6 Bulb Inrush Mode (BIM)
        7. 7.3.3.7 Integrated PWM Generator
      4. 7.3.4 Protection and Diagnostics
        1. 7.3.4.1 Undervoltage on VM
        2. 7.3.4.2 Overcurrent Protection
        3. 7.3.4.3 Over Temperature Protection
        4. 7.3.4.4 Over Temperature Warning
        5. 7.3.4.5 Over Temperature and Overcurrent Protection in Limp Home Mode
        6. 7.3.4.6 Reverse Polarity Protection
        7. 7.3.4.7 Over Voltage Protection
        8. 7.3.4.8 Output Status Monitor
        9. 7.3.4.9 Open Load Detection in ON State
          1. 7.3.4.9.1 Open Load at ON - direct channel diagnosis
          2. 7.3.4.9.2 Open Load at ON - diagnosis loop
          3. 7.3.4.9.3 OLON bit
      5. 7.3.5 SPI Communication
        1. 7.3.5.1 SPI Signal Description
          1. 7.3.5.1.1 Chip Select (nSCS)
            1. 7.3.5.1.1.1 Logic high to logic low Transition
            2. 7.3.5.1.1.2 Logic low to logic high Transition
          2. 7.3.5.1.2 Serial Clock (SCLK)
          3. 7.3.5.1.3 Serial Input (SDI)
          4. 7.3.5.1.4 Serial Output (SDO)
        2. 7.3.5.2 Daisy Chain Capability
        3. 7.3.5.3 SPI Protocol
        4. 7.3.5.4 SPI Registers
          1. 7.3.5.4.1  Standard Diagnosis Register
          2. 7.3.5.4.2  Output control register
          3. 7.3.5.4.3  Bulb Inrush Mode Register
          4. 7.3.5.4.4  Input 0 Mapping Register
          5. 7.3.5.4.5  Input 1 Mapping Register
          6. 7.3.5.4.6  Input Status Monitor Register
          7. 7.3.5.4.7  Open Load Current Control Register
          8. 7.3.5.4.8  Output Status Monitor Register
          9. 7.3.5.4.9  Open Load at ON Register
          10. 7.3.5.4.10 EN_OLON Register
          11. 7.3.5.4.11 Configuration Register
          12. 7.3.5.4.12 Output Clear Latch Register
          13. 7.3.5.4.13 FPWM Register
          14. 7.3.5.4.14 PWM0 Configuration Register
          15. 7.3.5.4.15 PWM1 Configuration Register
          16. 7.3.5.4.16 PWM_OUT Register
          17. 7.3.5.4.17 MAP_PWM Register
          18. 7.3.5.4.18 Configuration 2 Register
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Suggested External Components
      2. 8.1.2 Application Plots
    2. 8.2 Typical Application
    3. 8.3 Layout
      1. 8.3.1 Layout Guidelines
      2. 8.3.2 Package Footprint Compatibility
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3.6 Bulb Inrush Mode (BIM)

Sometimes one or more of the outputs of the device need to drive capacitive loads such as lamps or electronic loads. In such scenarios, after the switch is turned ON, the inrush current can reach the overload current threshold, thereby latching the channel OFF. In normal operation the device waits until the microcontroller sends an SPI command to clear the latches (CLRx bits) allowing the channel to turn ON again. Usually this delay is too long to start up the capacitive load.

If the corresponding bit BIMx is set to 1b, if the channel reaches the overload current or the overtemperature threshold and latches OFF, the channel restarts automatically after a time tINRUSH, allowing the load to go out of the inrush phase. A time diagram is shown in Figure 7-11. As shown, the counter starts when the channel is switched ON. Every channel switch OFF (independently from the entity controlling the channel) resets BIMx to 0b.

While BIMx bits are set to 1b, ERRx bits can also set to 1b but this doesn’t latch the channel OFF.

An internal timer sets the BIMx bits back to 0b after 40ms (parameter tBIM) to prevent an excessive thermal stress to the channel, especially in case of short circuit at the output. The device allows a per-channel selection of Bulb Inrush Mode (BIM) to be flexible without any reliability risk.

DRV81242-Q1 Bulb Inrush Mode (BIM) Operation Figure 7-11 Bulb Inrush Mode (BIM) Operation