This little board is an easy way to use Freescale’s MC33887 DC motor driver. Thanks to a 5-28 V operating range, current output up to 5 A (2.5 A continuous), and extra features such as current sensing and over-current protection, the 33887 is an excellent general-purpose motor driver.
These compact carriers for the Freescale Semiconductor MC33887 motor driver integrated circuit are an easy way to connect a brushed DC motor running from 5 to 28 V and drawing up to 5 A (peak) to your project. The board incorporates all of the components of the typical application diagram on page 25 of the MC33887 datasheet, plus motor-direction LEDs and a FET for reverse battery protection. All you need to add is a microcontroller or other control circuit to turn the H-Bridge on and off. If you have two motors to control, please consider the Dual MC33887 motor driver carrier. For a very similar motor driver that supports ultrasonic (up to 20 kHz) PWMs and a wider logic voltage range (3 – 5 V), please consider the MC33926 motor driver carrier or Dual MC33926 motor driver carrier.
In a typical application, the power connections are made on one end of the board, and the control connections (5V logic) are made on the other end. The enable (EN) pin does not have a pull-up resistor, so you must pull it to +5 V in order to wake the chip from sleep mode. The fault-status (FS, active low) output pin may be left disconnected if you do not want to monitor the fault conditions of the motor driver; if you do connect it you must use an external pull-up resistor to pull the line high. IN1 and IN2 control the direction of the motor, and D2 can be PWMed to control the motor’s speed. D2 is the “not disabled” line: it disables the motor driver when it is driven low (another way to think of it is it enables the motor driver when driven high). Whenever D1 or D2 disable the motor driver, the FS pin will be driven low. The feedback (FB) pin outputs a voltage proportional to the H-Bridge high-side current, providing approximately 0.59 volts per amp of output current.
The MC33887 motor driver carrier PCB comes with two 47 uF, 35 V surface-mounted capacitors and holes for installing an additional through-hole capacitor. This third capacitor can be added in conjunction with the two surface-mount capacitors to further limit disturbances on the main power line, or it can be added in place of the two surface-mount capacitors to allow the MC33887 motor driver carrier to function at high voltages.
*Typical results using MC33887 motor driver carrier with 100% duty cycle at room temperature with no forced air flow or heat sink.
- Size:1.03" x 1.35"
- Motor driver:MC33887
- Motor channels:1
- Minimum operating voltage:5 V
- Maximum operating voltage:28 V
- Continuous output current per channel:2.5 A
- Peak output current per channel:5 A
- Current sense:0.59 V/A
- Maximum PWM frequency:10 kHz
- Minimum logic voltage:4.0 V1
- Maximum logic voltage:5.5 V2
- Reverse voltage protection?:Y