1300 Henley Court Pullman, WA 99163 509.334.6306 www.digilentinc.com PmodDHB1TM Reference Manual Revised May 24, 2016 This manual applies to the PmodDHB1 rev. B Overview The Digilent PmodDHB1 is a dual H-Bridge motor driver that is capable of driving two DC motors, a bipolar stepper motor, and other devices with inductive loads. Features include: The PmodDHB1. 1 Dual H-Bridge capable of 1.5A RMS Two quadrature encoder channels for motor feedback Two JST 6-pin ports for connection to Digilent motor/gearbox Over-current protection Recommended 10.8 V max motor voltage Logic input voltage range of 2.5 V to 5 V Small PCB size for flexible designs 1.3" x 1.8" (3.3 cm x 4.6 cm) Follows Digilent Pmod Interface Specification Type 5 Functional Description The PmodDHB1 utilizes TI's DRV8833 to drive a variety of systems. With the two built in H-Bridges and pull down resistors on the inputs, users may run two DC motors or a single bipolar stepper motor in fast decay mode. The DRV8833 chip provides over-current protection on the motor drive circuits. Each internal drive FET is independently monitored for an over-current condition and will be shut down internally to protect the chip. When an over-current condition is sensed the chip will shut down the FET with the fault and then set the NFAULT pin low signaling a fault condition on the chip. The remaining FETs will continue to operate as normal. When the fault condition is over, the chip will self-reset and return the NFAULT logic level to logic high. 2 Interfacing with the Pmod The PmodDHB1 communicates with the host board via the GPIO protocol. By driving the enable (EN) pins with a PWM signal and a logic level low or high voltage signal on the direction (DIR) pins, users are able to run DC motors at various speeds. DOC#: 502-259 Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Page 1 of 3 PmodDHB1TM Reference Manual A truth table listing out the various possible combinations and results of the EN and DIR pins is provided below: DIR1 0 0 1 1 EN1 0 1/PWM 0 1/PWM Result Stop Forward Stop Reverse DIR2 0 0 1 1 EN2 0 1/PWM 0 1/PWM Result Stop Forward Stop Reverse Table 1. Truth table list. Note that like all H-Bridges, it is recommended that the EN pin is driven to a low voltage state before changing the voltage state on the DIR pin to ensure that the FETs are not short-circuited. Two sensor feedback pins for both motors are provided so users can capture the signals coming from any Hall Effect Sensors in quadrature. 2.1 Pinout Description Tables Pin 1 2 3 4 5 6 Signal EN1 DIR1 S1A S1B GND VCC Header J1 Description Pin Motor 1 Enable 7 Motor 1 Direction 8 Motor 1 Sensor A Feedback 9 Motor 1 Sensor B Feedback 10 Power Supply Ground 11 Power Supply (3.3V/5V) 12 Header J4 - Motor Voltage Pin Signal Description 1 VM Motor Power 2 GND Power Supply Ground Header J5 - M1 Power Pin Signal Description 1 M1+ Motor 1 Positive Supply 2 M1Motor 1 Negative Supply Header J6- M2 Power Pin Signal Description 1 M2+ Motor 2 Positive Supply 2 M2Motor 2 Negative Supply Header J7- M1 Feedback Pin Signal Description 1 SA1-IN Sensor A From Motor 1 2 SB1-IN Sensor B From Motor 1 3 GND Power Supply Ground 4 VCC Power Supply (3.3V) Signal EN2 DIR2 S2A S2B GND VCC Description Motor 2 Enable Motor 2 Direction Motor 2 Sensor A Feedback Motor 2 Sensor B Feedback Power Supply Ground Power Supply (3.3V/5V) Header J2- M1 JST 6-Pin Motor Connector Header J3- M2 JST 6-Pin Motor Connector Header J8- M2 Feedback Pin Signal Description 1 SA2-IN Sensor A From Motor 2 2 SB2-IN Sensor B From Motor 2 3 GND Power Supply Ground 4 VCC Power Supply (3.3V) Header J9- Fault Pin Signal Description 1 NFAULT Overcurrent Condition 2 GND Power Supply Ground Header J10- Sleep Pin Signal Description 1 NSLEEP Puts device into sleep state 2 GND Power Supply Ground Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Page 2 of 3 PmodDHB1TM Reference Manual Any external power applied to the PmodDHB1 must be within 2.7V and 10.8V; however, it is recommended that Pmod is operated at 3.3V. 3 Physical Dimensions The pins on the pin header are spaced 100 mil apart. The PCB is 1.3 inches long on the sides parallel to the pins on the pin header and 1.8 inches long on the sides perpendicular to the pin header. Copyright Digilent, Inc. All rights reserved. Other product and company names mentioned may be trademarks of their respective owners. Page 3 of 3