SLVSI23A September   2025  – December 2025 DRV81646

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specification
    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 Timing Requirements
    7.     13
    8. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Control Interface and Slew Rate (RSLEW/CNTL)
      2. 6.3.2 Current Sensing With FET Source Terminals
      3. 6.3.3 Integrated Clamp Diode, VCLAMP
      4. 6.3.4 Protection Circuits
        1. 6.3.4.1 ILIM Analog Current Limit
          1. 6.3.4.1.1 Effect of Load Resistance on Power Dissipation Before TSD
        2. 6.3.4.2 Cut-Off Delay (COD)
        3. 6.3.4.3 INRUSH Mode
        4. 6.3.4.4 Thermal Shutdown (TSD)
        5. 6.3.4.5 Undervoltage Lockout (UVLO)
      5. 6.3.5 Fault Conditions Summary
    4. 6.4 Device Functional Modes
      1. 6.4.1 Hardware Interface Operation
      2. 6.4.2 Parallel Outputs
      3. 6.4.3 SPI Mode
        1. 6.4.3.1 Parity Bit Calculation
        2. 6.4.3.2 SPI Input Packet
        3. 6.4.3.3 SPI Response Packet
        4. 6.4.3.4 SPI Error Reporting
        5. 6.4.3.5 SPI Daisy Chain
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 External Components
      2. 7.2.2 Continuous Current Capability
      3. 7.2.3 Power Dissipation
      4. 7.2.4 Application Curves
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Bulk Capacitance
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.1 Overview

The DRV81646 is a versatile four-channel low-side switching driver that operates within a wide voltage range of 4.5V to 65V, supporting a broad spectrum of load current requirements. This device incorporates four integrated low-side switches, each featuring low on-resistance of 140mΩ and equipped with a freewheeling diode connected to the VCLAMP pin. This configuration enables users to either recirculate current flow or attach an external Transient Voltage Suppressor (TVS) for safe management of inductive load turn-off.

The device offers flexible control through multiple interface options, including hardware GPIO and standard 4-wire SPI communication. Each channel is equipped with dedicated overtemperature protection and adjustable current limiting capabilities, which can be configured using an external resistor on the ILIM pin. An optional cut-off delay (COD) feature is available to restrict the time duration of current-limiting events on individual channels, thereby preventing damage to both the device and connected loads. Output switching rates can be customized through resistor configuration on the RSLEW/CNTL pin, providing enhanced control flexibility over the output switches. Additionally, the device includes an INRUSH mode that temporarily elevates the current limit threshold to accommodate capacitive load applications.

The DRV81646 provides a dedicated fault output pin (nFAULT) for indicating error conditions, while individual channel fault status monitoring is available when operating in SPI mode. This capability enables rapid identification and response to any fault conditions that occur, supporting efficient and reliable system operation.