SLVSBG3C June   2012  – June 2016 DRV120

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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
    4. 7.4 Device Functional Modes
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  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 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

8 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality.

8.1 Application Information

The DRV120 device is designed to operate a solenoid valve or relay. A typical DC input design will be outlined in Typical Application. Approximate resistor and capacitor values for the peak current, hold current, and keep time will be derived for a sample application.

8.2 Typical Application

DRV120 typ_app2_lvsbg3.gif Figure 5. Default Configuration

8.2.1 Design Requirements

The key elements to identify here are the system input voltage, peak current, hold current, and peak keep time values required for the solenoid or relay being used. With these values, approximate RS, RPEAK, RHOLD (for 14-pin package), and CKEEP values can be determined and the proper FET and diode can be identified. ROSC can be varied in order to tune the circuit to the chosen solenoid or relay.

8.2.2 Detailed Design Procedure

First, with the known peak current, hold current, and peak keep time values known, the RPEAK, RHOLD (for 14-pin package), and CKEEP values can be determined. Calculation will proceed based on example values shown in Table 1.

Table 1. Sample Application Values

VARIABLE VALUE
Peak current 150 mA
Hold current 50 mA
Keep time 100 ms

RPEAK and RHOLD (if applicable) can be determined using Equation 2 and Equation 3. For the sample values, RPEAK is set to 111 kΩ and RHOLD can be shorted to GND. TI recommends that a 0-Ω resistor is used for prototyping in case changes to this value are desired.

Next, CKEEP can be set based on Equation 1, 1.33 µF for the sample values. ROSC can initially be shorted to GND, but again a 0-Ω resistor is recommended for prototyping. Additionally, a filter on the SENSE line may be added if it will be in a high-noise environment and is recommended for prototyping. Typical values for this are 1 kΩ and 100 pF.

Finally, a current recirculation diode must be chosen based on the current values defined in Table 1. The current recirculation diode should be a fast recovery diode.

8.2.3 Application Curves

DRV120 DRV120_TypicalApplicationCurve.png
Lind = 1 H Rind = 50 Ω
Figure 6. ISOLENOID, EN, and VIN vs Time