SLVSB18H March   2012  – August 2016 DRV8835

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 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Protection Circuits
        1. 7.3.1.1 Overcurrent Protection (OCP)
        2. 7.3.1.2 Thermal Shutdown (TSD)
        3. 7.3.1.3 Undervoltage Lockout (UVLO)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Bridge Control
      2. 7.4.2 Sleep Mode
  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
        1. 8.2.2.1 Motor Voltage
        2. 8.2.2.2 Lower-Power Operation
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
    1. 9.1 Bulk Capacitance
    2. 9.2 Power Supplies and Input Pins
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
      1. 10.3.1 Power Dissipation
      2. 10.3.2 Heatsinking
  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

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メカニカル・データ（パッケージ｜ピン）
サーマルパッド・メカニカル・データ
発注情報

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 DRV8835 is used in one or two motor control applications. Configure the DRV8835 in parallel to provide double the current to one motor. The following design procedure can be used to configure the DRV8835 in a brushed motor application.

8.2 Typical Application

The two H-bridges in the DRV8835 connect in parallel for double the current of a single H-bridge. Figure 6 shows the connections.

DRV8835 parallel1_lvsb18.gif Figure 6. Parallel Mode Connections

8.2.1 Design Requirements

Table 5 lists the design requirements.

Table 5. Design Requirements

DESIGN PARAMETER REFERENCE VALUE
Motor voltage VCC 4 V
Motor RMS current IRMS 0.3 A
Motor startup current ISTART 0.6 A
Motor current trip point ILIMIT 0.5 A

8.2.2 Detailed Design Procedure

8.2.2.1 Motor Voltage

The appropriate motor voltage depends on the ratings of the motor selected and the desired RPM. A higher voltage spins a brushed DC motor faster with the same PWM duty cycle applied to the power FETs. A higher voltage also increases the rate of current change through the inductive motor windings.

8.2.2.2 Lower-Power Operation

When entering sleep mode, TI recommends setting all inputs as a logic low to minimize system power.

8.2.3 Application Curve

The following scope captures motor startup as VCC ramps from 0 V to 6 V. Channel 1 is VCC, Channel 2 is VM, and Channel 4 is the motor current of an unloaded motor during startup. The motor used is a NMB Technologies Corporation, PPN7PA12C1. As VCC and VM ramp, the current in the motor increases until the motor speed builds up. The motor current then reduces for normal operation.

Inputs are set as follows:

  • Mode: IN/IN
  • AIN1: High
  • AIN2: Low
DRV8835 DRV8835_3p3Vcc_6VM.png
Channel 1: VM IN1 = Logic High
Channel 2: VCC IN2 = Logic Low Motor used: NMB Technologies Corporation, PPN7PA12C1
Channel 4: Motor current
Figure 7. Motor Startup With No Load