SLVSB17D March 2012 – April 2016 DRV8836
PRODUCTION DATA.
8 Application and Implementation
NOTE
The 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 DRV8836 is used in one or two motor control applications. When configured in parallel, the DRV8836 provides double the current to one motor.
8.2 Typical Application
The two H-bridges in the DRV8836 can be connected in parallel for double the current of a single H-bridge. Figure 5 shows the connections.
The following design is a common application of the DRV8836.
Figure 5. Parallel Mode Connections
8.2.1 Design Requirements
The design requirements are shown in Table 5.
Table 5. Design Requirements
| DESIGN PARAMETER | REFERENCE | EXAMPLE 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
The following design procedure can be used to configure the DRV8836 in a brushed motor application.
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 Low-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, and Channel 4 is the motor current of an unloaded motor during startup. The motor used is a NMB Technologies Corporation OOB7PA12C, PPN7PA12C1. As VCC ramps 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
Figure 6. Motor Startup With No Load