SLVAE59A February   2019  – April 2022 DRV8242-Q1 , DRV8243-Q1 , DRV8244-Q1 , DRV8245-Q1 , DRV8343-Q1 , DRV8702-Q1 , DRV8702D-Q1 , DRV8703-Q1 , DRV8703D-Q1 , DRV8803 , DRV8804 , DRV8805 , DRV8806 , DRV8860 , DRV8873 , DRV8873-Q1 , DRV8874 , DRV8874-Q1 , DRV8876 , DRV8876-Q1 , DRV8935 , DRV8955

 

  1.   Trademarks
  2. 1Introduction
    1. 1.1 Types of Solenoids
  3. 2Solenoid Driving Typologies
    1. 2.1 Low-Side and High-Side Configuration
    2. 2.2 Half-Bridge and H-Bridge Driver Configurations
  4. 3Basics of Driving Solenoid Loads
    1. 3.1 Current Control
    2. 3.2 Fast Discharging Circuits
      1. 3.2.1 Freewheeling and Clamping
      2. 3.2.2 Passive Voltage Clamping
  5. 4DRV Motor Driver Features for Solenoid Driving
    1. 4.1 Current Sensing and Regulation Solutions
    2. 4.2 Independent Low-/High-Side Driving
    3. 4.3 Half-Bridge Driving
    4. 4.4 Integrated and Gate Driver H-Bridges
  6. 5Summary
  7. 6Revision History

2.1 Low-Side and High-Side Configuration

The typical low-side or high-side driver configuration uses a single MOSFET with enough current handling capability to drive the solenoid. High- and low-side drivers are good choices for push/pull solenoids with a return spring. Figure 2-2 shows the LS/HS configuration, with optional external clamp.

Figure 2-2 Low-Side and High-Side Configurations

When the MOSFET is enabled, it conducts all the current needed to energize the solenoid. When the MOSFET is disabled, the current in the solenoid must freewheel through a diode, or be allowed to continue flowing or decay to zero, otherwise the MOSFET can see large voltage spikes. The freewheeling diode across the solenoid provides this low impedance path for solenoid current to flow. Figure 2-3 shows a low-side driver.

Figure 2-3 A Power MOSFET Transistor and a Freewheeling Diode Used to Drive a Solenoid