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ManualsBrandsPololu ManualsBrushed DC Motor Controllers20A, 5.5 - 50V Single Motor Controller

Table Of Contents

RB-Pol-169

Pololu 20A, 5.5 - 50V Single Motor Controller

This discrete MOSFET H-bridge motor driver enables bidirectional control of one high-power DC

brushed motor. The compact 1.8×1.2-inch board supports a wide 5.5 to 50 V voltage range and is

efficient enough to deliver a continuous 20 A without a heat sink. This version outputs an analog

voltage proportional to the motor current, and an extra control input allows for coasting in addition to

the driving and braking offered by the other Pololu high-power motor drivers.

Overview

The Pololu high-power motor driver is a discrete MOSFET H-bridge designed to drive large DC

brushed motors. The H-bridge is made up of one N-channel MOSFET per leg, and most of the board’s

performance is determined by these MOSFETs (the rest of the board contains the circuitry to take user

inputs and control the MOSFETs). The MOSFET datasheet is available under the “Resources” tab. The

Summary of content (7 pages)

PAGE 1
RB-Pol-169 Pololu 20A, 5.5 - 50V Single Motor Controller This discrete MOSFET H-bridge motor driver enables bidirectional control of one high-power DC brushed motor. The compact 1.8×1.2-inch board supports a wide 5.5 to 50 V voltage range and is efficient enough to deliver a continuous 20 A without a heat sink.
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board has an absolute maximum voltage rating of 50 V; higher voltages can permanently destroy the motor driver. Under normal operating conditions, ripple voltage on the supply line can raise the maximum voltage to more than the average or intended voltage, so a safe maximum voltage is approximately 44 V. Note: Battery voltages can be much higher than nominal voltages when they are charged, so the maximum battery voltage we recommend is 36 V unless appropriate measures are taken to limit the peak voltage.
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access to monitor the motor’s power supply or pass it on to low-current devices (it should not be used for high current). The board also provides a regulated 5V pin which can provide a few milliamps (this is typically insufficient for a whole control circuit but can be useful as a reference or for very lowpower microcontrollers). This pin can be shorted to VCS to power the current sensor, or VCS can be supplied with 5 V externally.
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higher power applications, use thick wires soldered directly to the board.) Connecting large capacitors across the power supply is recommended; one way to do it is between the '+' and '-' holes, as shown below. The four mounting holes are intended to be used with #2 screws (not included). Motor Control Options The motor driver can be used in several different modes: • Sign-magnitude (drive-brake): With PWML disconnected or held high, apply a pulse-widthmodulated (PWM) signal to the PWMH pin.
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Motor Driver Truth Table PWMH PWML DIR OUTA OUTB Operation H H L GND V+ Forward H H H V+ GND Backward L H X GND GND Brake Low H L X V+ V+ Brake High L L X Z Z Coast X = don’t care (same for input H or L); Z = high impedance (outputs disconnected) PWM Frequency The motor driver supports PWM frequencies as high as 40 kHz, though higher frequencies result in higher switching losses in the motor driver.
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Warning: This motor driver has no over-current or over-temperature shut-off. Either condition can cause permanent damage to the motor driver. We recommend you use the current-sense output CS to monitor your current draw if your application will put the driver close to its limits of operation. Fault Conditions The motor driver can detect three different fault states, which are reported on the FF1 and FF2 pins. The detectable faults are short circuits on the output, under-voltage, and over-temperature.
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driver 24v20 High-power motor driver 24v12 High-power motor driver 36v20 CS High-power motor driver 36v15 High -power motor driver 36v9 28 12 36 20 36 15 36 9 Note: Please consider our Simple Motor Controllers as alternatives to these motor drivers. They have very similar power characteristics and offer high-level interfaces (e.g. USB, RC hobby servo pulses, analog voltages, and TTL serial commands) that make them much easier to use for many applications. Dimensions Size: 1.8" x 1.