The DRV8837CDSGR is a product from Texas Instruments, specifically from the DRV88xx series of motor drivers. This model is a low-voltage motor driver, typically used in small motors for applications in robotics, mobile devices, and more.
The DRV8837CDSGR uses a SSOP-8 (Shrink Small Outline Package) with 8 pins.
Pin Function Table (SSOP-8 Package)
Pin Number Pin Name Pin Function Description 1 IN1 Input signal for motor direction control (Low = Reverse, High = Forward) 2 IN2 Input signal for motor direction control (Low = Reverse, High = Forward) 3 VSTBY Standby (Low = Standby mode, High = Normal operation) 4 VM Motor supply voltage input (Typically 2.5V to 10.8V) 5 GND Ground (Common ground for Power and logic signals) 6 VDD Logic supply voltage input (Typically 1.8V to 5.5V) 7 OUT1 Output to motor terminal 1 (Motor A) 8 OUT2 Output to motor terminal 2 (Motor B)Detailed Pin Function Descriptions
IN1 and IN2 (Pins 1 and 2): These are the input pins for controlling the direction of the motor. IN1 controls the direction with respect to IN2. If both are high, the motor runs in one direction, and if both are low, it runs in the reverse direction. If IN1 is high and IN2 is low, the motor operates in forward direction, and vice versa. VSTBY (Pin 3): This pin is used to place the driver into standby mode. When VSTBY is low, the motor driver is disabled, and the outputs are in a high-impedance state. When VSTBY is high, the driver is enabled, and the motor can be controlled. VM (Pin 4): This pin connects to the motor power supply voltage. It provides power to the motor and is the input for motor voltage. It must be within the specified voltage range for the motor to operate correctly. GND (Pin 5): Ground pin that serves as the common reference for the entire circuit. This pin should be connected to the ground of the power supply. VDD (Pin 6): This is the logic power supply input. It powers the internal logic of the device, and its voltage should be within the specified range for correct operation. OUT1 and OUT2 (Pins 7 and 8): These pins provide the output to the motor. Depending on the input signals at IN1 and IN2, the voltage applied to OUT1 and OUT2 will change to drive the motor in the desired direction.Circuit Principle and Operation
The DRV8837CDSGR motor driver operates in H-bridge configuration. The control inputs (IN1 and IN2) determine the polarity of the motor's output voltage at OUT1 and OUT2. The output voltage to the motor is based on the direction set by these inputs. Additionally, the device provides a low-power standby mode when VSTBY is low, helping to conserve energy in applications that require low standby power consumption.
In normal operation, when IN1 and IN2 are both high or both low, the motor will rotate in a specific direction, while different combinations of input signals will change the polarity of the output voltage to reverse the motor's direction.
FAQs (Frequently Asked Questions)
What is the voltage range for the motor (VM) pin? The voltage range for the VM pin is 2.5V to 10.8V. What is the voltage range for the logic (VDD) pin? The VDD pin operates within a voltage range of 1.8V to 5.5V. What happens when the VSTBY pin is low? When the VSTBY pin is low, the motor driver enters standby mode, and the outputs are in a high-impedance state, meaning the motor is not powered. How do IN1 and IN2 control motor direction? IN1 and IN2 control the motor direction by setting the voltage polarity at the output pins. High/low signals determine the rotation direction. Can the DRV8837CDSGR drive a 12V motor? No, the VM voltage range is 2.5V to 10.8V, so it cannot drive motors requiring a 12V supply. What happens if VM voltage is below 2.5V? If the VM voltage is below 2.5V, the motor driver will not be able to properly power the motor, and it may not function correctly. How can I reduce power consumption in idle mode? To reduce power consumption, the VSTBY pin can be pulled low to enter standby mode, which disables the motor driver. Is the DRV8837CDSGR compatible with PWM signals? Yes, the driver can accept PWM signals for controlling the speed of the motor, which can be applied to the input pins. What is the maximum output current for the DRV8837CDSGR? The maximum output current the driver can provide to the motor is around 1.5A.Can I use the DRV8837CDSGR with bi-directional motors?
Yes, you can use this motor driver for bi-directional motor control by adjusting the logic inputs (IN1 and IN2) accordingly.What happens if I connect the motor backward?
If the motor is connected backward, the motor will still rotate in the opposite direction, but you may need to reverse the connections at the OUT1 and OUT2 pins to correct the direction.Can I use this motor driver in a 5V system?
Yes, the VDD pin can be powered with 5V, as it supports a voltage range up to 5.5V.How do I prevent over-voltage on the motor (VM) input?
You can use a voltage regulator to ensure the VM input voltage remains within the operating range of 2.5V to 10.8V.Can I use the DRV8837CDSGR with stepper motors?
No, the DRV8837CDSGR is a basic DC motor driver and is not designed for stepper motors, which require more complex control.What is the power dissipation of the DRV8837CDSGR?
Power dissipation depends on the load and operating conditions but typically is quite low for such a small driver.Does the DRV8837CDSGR have thermal protection?
Yes, it includes thermal shutdown protection to prevent damage from overheating.Can the motor driver be used for both small and large motors?
It is best suited for small motors, typically with low voltage and current requirements, due to its current limit and voltage range.How does the DRV8837CDSGR handle motor braking?
The device doesn't specifically offer braking functionality, but shorting the motor windings can cause it to decelerate quickly.Can I use this device in a battery-powered system?
Yes, it is designed for low-power applications and can be used in battery-powered systems.What happens if I leave the IN1 or IN2 pins floating?
Floating input pins can result in unpredictable motor behavior, so they should not be left floating. Use pull-up or pull-down resistors as needed.