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

Package Options

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

7 Detailed Description

7.1 Overview

The DRV8835 is an integrated motor-driver solution used for brushed motor control. The device integrates two
H-bridges, and drives two DC motor or one stepper motor. The output driver block for each H-bridge consists of
N-channel power MOSFETs. An internal charge pump generates the gate drive voltages. Protection features include overcurrent protection, short circuit protection, undervoltage lockout, and overtemperature protection.

The bridges connect in parallel for additional current capability.

The DRV8835 allows separation of the motor voltage and logic voltage if desired. If VM and VCC are less than
7 V, the two voltages can be connected.

The mode pin allow selection of either a PHASE/ENABLE or IN/IN interface.

7.2 Functional Block Diagram

DRV8835 fbd_lvsb18.gif

7.3 Feature Description

7.3.1 Protection Circuits

The DRV8835 is fully protected against undervoltage, overcurrent, and overtemperature events.

7.3.1.1 Overcurrent Protection (OCP)

An analog current limit circuit on each FET limits the current through the FET by removing the gate drive. If this analog current limit persists for longer than the OCP time, all FETs in the H-bridge disable. After approximately
1 ms, the bridge re-enable automatically.

Overcurrent conditions on both high-side and low-side devices; a short to ground, supply, or across the motor winding result in an overcurrent shutdown.

7.3.1.2 Thermal Shutdown (TSD)

If the die temperature exceeds safe limits, all FETs in the H-bridge disable. Operation automatically resumes once the die temperature falls to a safe level.

7.3.1.3 Undervoltage Lockout (UVLO)

If at any time the voltage on the VCC pins falls below the undervoltage lockout threshold voltage, all circuitry in the device disable, and internal logic resets. Operation resumes when VCC rises above the UVLO threshold.

Table 1. Device Protection

FAULT CONDITION ERROR REPORT H-BRIDGE INTERNAL CIRCUITS RECOVERY
VCC undervoltage (UVLO) VCC < VUVLO None Disabled Disabled VCC > VUVLO
Overcurrent (OCP) IOUT > IOCP None Disabled Operating tOCR
Thermal Shutdown (TSD) TJ > TTSD None Disabled Operating TJ < TTSD – THYS

7.4 Device Functional Modes

The DRV8835 is active when the VCC is set to a logic high. When in sleep mode, the H-bridge FETs are disabled (HIGH-Z).

Table 2. Device Operating Modes

OPERATING MODE CONDITION H-BRIDGE INTERNAL CIRCUITS
Operating nSLEEP high Operating Operating
Sleep mode nSLEEP low Disabled Disabled
Fault encountered Any fault condition met Disabled See Table 1

7.4.1 Bridge Control

Two control modes are available in the DRV8835: IN/IN mode, and PHASE/ENABLE mode. IN/IN mode is selected if the MODE pin is driven low or left unconnected; PHASE/ENABLE mode is selected if the MODE pin is driven to logic high. Table 3 and Table 4 show the logic for these modes.

Table 3. IN/IN Mode

MODE xIN1 xIN2 xOUT1 xOUT2 FUNCTION
(DC MOTOR)
0 0 0 Z Z Coast
0 0 1 L H Reverse
0 1 0 H L Forward
0 1 1 L L Brake

Table 4. Phase/Enable Mode

MODE xENABLE xPHASE xOUT1 xOUT2 FUNCTION
(DC MOTOR)
1 0 X L L Brake
1 1 1 L H Reverse
1 1 0 H L Forward

7.4.2 Sleep Mode

If the VCC pin reaches 0 V, the DRV8835 enters a low-power sleep mode. In this state all unnecessary internal circuitry powers down. For minimum supply current, all inputs should be low (0 V) during sleep mode.