This breakout board for the MPS MPQ6612A motor driver offers a wide operating voltage range of 4 V to 40 V and can deliver up to 4 A continuous to a single brushed DC motor. The MPQ6612A has built-in current sensing and regulation that limits the peak motor current to 7.5 A by default, as well as protection against over-current and over-temperature. The carrier board also adds reverse-voltage protection. This version does not include any connectors.

This product is a carrier board for the Monolithic Power Systems (MPS) MPQ6612A brushed DC motor driver; we therefore recommend careful reading of the MPQ6612A datasheet (573k pdf).

The MPQ6612A is an H-bridge motor driver IC that can be used for bidirectional control of one brushed DC motor with a supply range of 4 V to 40 V. It can deliver up to approximately 4 A continuous on our carrier board and features configurable current sensing and current limiting. The board ships populated with all of its SMD components, including the MPQ6612A.

This version does not include any connectors, and its through-holes support a number of different connector options (see the connections section below for information about connector compatibility). We also have a version with connectors installed that does not require any soldering to use.

Features and specifications:

H-bridge motor driver: can drive one DC motor
Motor supply voltage: 4 V to 40 V
Output current: up to 4 A continuous (7.5 A default current limit); max continuous current depends on operating voltage, PWM frequency, and ambient conditions
Supports 1.5 V to 5 V logic (6.5V absolute max)
Integrated current sensing and adjustable active current regulation
Motor indicator LEDs (indicates what the outputs are doing even when no motor is connected)
Protection against over-current and over-temperature with fault output indicator
Carrier board adds reverse-voltage protection
Size: 0.8″×0.9″
One 0.086″ mounting hole for #2 or M2 screws

Using the motor driver

Pinout:

This board features motor indicator LEDs that can be used to test that motor driver outputs are working as expected before actually connecting a motor (this can be especially helpful in detecting problems due to insufficient power supplies). The LED brightness increases with motor speed, and the LED color changes with direction.

Minimal wiring diagram

Aside from motor and power connections (including a logic voltage connection to SLEEP), the only required control pins are IN1 and IN2. The following simplified truth table shows how these two control pins affect the driver outputs:

Current sensing and current limiting

The MPQ6612A can sense the motor current and actively limit it by using constant-off-time PWM current regulation (current chopping). The feedback sensitivity and current limiting threshold are set by a resistance connected between the ISET pin and ground. The carrier board is populated with a 2 kΩ pull-down resistor on ISET, which makes the VISEN pin output a voltage of 200 mV/A and limits the current to 7.5 A by default. This behavior can be customized by adding an external pull-down resistor to the ISET pin in parallel with the one already on the carrier. This will reduce the overall resistance, increasing the current limit and decreasing the VISEN sensitivity. Connecting ISET directly to GND disables current limiting (and current sensing). To reduce the current limit and increase the VISEN sensitivity, the on-board 2 kΩ surface mount resistor would need to be removed and replaced with a surface mount or external resistor of a larger value. Refer to the MPQ6612A datasheet for more information about the driver’s current sensing and current limiting.

Real-world power dissipation considerations

The MPQ6612A is rated for a maximum continuous current of 5 A, which typically requires extra airflow or heat sinking to achieve. The actual current you can deliver will depend on how well you can keep the motor driver cool, and the carrier’s printed circuit board is designed to help with this by drawing heat out of the motor driver chip. On our carrier board at room temperature and with no forced air flow, the chip is able to deliver 5 A for between 30 seconds and a few minutes before activating the chip’s thermal protection; a continuous current of 4 A is typically sustainable for many minutes without triggering a thermal shutdown. At the board’s default current limit of 7.5 A, thermal shutdown occurs within a few seconds.

This product can get hot enough to burn you long before the chip overheats. Take care when handling this product and other components connected to it.

Schematic: