DRV8818PWPR Detailed explanation of pin function specifications and circuit principle instructions
The DRV8818PWPR is a motor driver integrated circuit (IC) from Texas Instruments. It is commonly used for driving bipolar stepper motors and other types of motors. Below, I will provide a detailed explanation of the pin functions and specifications, followed by a complete FAQ section as requested.
Package Type
DRV8818PWPR comes in the HTSSOP-28 (Heat Sink Thin Shrink Small Outline Package), which has 28 pins.Pin Function List (28 Pins)
Here is a detailed list of all 28 pins, describing their function and usage.
Pin Number Pin Name Function Description 1 VDD Power supply pin for internal logic. Typically connected to 3.3V or 5V depending on the logic level. 2 GND Ground pin for the IC. 3 VM Motor voltage supply pin. This is where the supply for the motor's power is connected. 4 OUT1 Output for the first coil of the stepper motor (A+). 5 OUT2 Output for the first coil of the stepper motor (A-). 6 OUT3 Output for the second coil of the stepper motor (B+). 7 OUT4 Output for the second coil of the stepper motor (B-). 8 GND Ground for the H-Bridge circuit. 9 FAULT Open-drain output pin. It is asserted low when the device encounters a fault condition like overcurrent. 10 REF Reference input for setting the current. Connect to a resistor for setting the current reference. 11 VREF Reference voltage output, typically used for setting the current control reference. 12 SLEEP Sleep mode control pin. Driving low puts the device in a low-power sleep mode. 13 RESET Active-low reset input. The device is reset when this pin is pulled low. 14 DIR Direction input pin. Controls the direction of the motor rotation. 15 STEP Step input pin. Receives step pulses for controlling the motor stepwise movement. 16 ISENSE Current sense pin for monitoring motor current. It connects to the current sensing circuitry. 17 VCP capacitor connection pin for voltage charge pump to provide adequate gate drive voltage. 18 CPHASE Capacitor connection for phase boost to increase gate drive voltage. 19 VREF2 Alternative reference voltage for current control, used when needed for specific configurations. 20 VSENSE Voltage sensing pin, used to monitor motor voltage. 21 VOUT Motor voltage output pin, responsible for driving the motor. 22 EN Enable pin. A high-level signal enables the IC, allowing motor driving operations. 23 VSS Power supply ground pin. 24 VDD2 Additional power supply pin for internal logic circuits, usually 3.3V or 5V. 25 VCC Another power supply pin that connects to the logic supply. 26 NC No connection, pin is left floating and is not used. 27 NC No connection, pin is left floating and is not used. 28 NC No connection, pin is left floating and is not used.Explanation of Pin Functions
Power Pins (VDD, VCC, VM, GND): These pins are essential for providing power to the motor driver and the logic circuits. Motor Driver Pins (OUT1, OUT2, OUT3, OUT4): These pins control the stepper motor coils. Each pair of outputs controls one motor phase. Control Pins (STEP, DIR, ENABLE, RESET, SLEEP): These are input pins that control the operation mode of the motor driver IC. The STEP pin receives clock pulses to drive the stepper motor. The DIR pin sets the direction of rotation, while ENABLE enables or disables the output stage. Current Control Pins (REF, VREF, ISENSE): These pins are used to set the current limits for motor operation, ensuring that the motor does not exceed the safe operating current. Fault Pin (FAULT): If the driver detects an issue such as an overcurrent condition, the FAULT pin is pulled low to indicate an error. Other Pins (CPHASE, VCP, VREF2): These pins are used for internal regulation and control of motor current and gate drive voltages.20 FAQ (Frequently Asked Questions)
Here are 20 frequently asked questions regarding the DRV8818PWPR motor driver IC.
1. Q: What is the purpose of the FAULT pin in the DRV8818PWPR? A: The FAULT pin signals a fault condition, such as overcurrent, thermal shutdown, or other issues, and it is asserted low during these conditions.
2. Q: What voltage range is supported by the VM pin in the DRV8818PWPR? A: The VM pin typically supports a motor supply voltage range from 4.5V to 45V.
3. Q: How do I set the current limit for the motor in the DRV8818PWPR? A: The current limit can be set by adjusting the REF and VREF pins, which control the reference voltage for current regulation.
4. Q: What is the purpose of the STEP pin? A: The STEP pin is used to input step pulses to control the movement of the motor in discrete steps.
5. Q: Can I use the DRV8818PWPR for bipolar stepper motors? A: Yes, the DRV8818PWPR is specifically designed for controlling bipolar stepper motors.
6. Q: What is the function of the DIR pin? A: The DIR pin sets the direction of rotation for the stepper motor when the STEP pin receives pulses.
7. Q: How do I put the DRV8818PWPR into sleep mode? A: To enter sleep mode, pull the SLEEP pin low. This reduces the power consumption of the device.
8. Q: What does the RESET pin do? A: The RESET pin resets the motor driver when pulled low, clearing any fault conditions.
9. Q: Can I control the speed of the stepper motor with the DRV8818PWPR? A: Yes, the speed is controlled by the frequency of the pulses sent to the STEP pin.
10. Q: What happens if the FAULT pin is pulled low? A: If the FAULT pin is pulled low, it indicates that a fault condition, such as overcurrent or thermal shutdown, has occurred.
11. Q: What is the recommended supply voltage for the DRV8818PWPR? A: The recommended supply voltage for logic is typically 3.3V or 5V, while the motor voltage should range from 4.5V to 45V.
12. Q: Can I use the DRV8818PWPR to drive unipolar motors? A: No, the DRV8818PWPR is designed specifically for bipolar motors.
13. Q: How can I check if the motor is running properly with the DRV8818PWPR? A: Monitor the outputs to ensure the expected signals are delivered to the motor coils, and check the FAULT pin for any error signals.
14. Q: How do I reset the DRV8818PWPR? A: To reset, drive the RESET pin low and then high.
15. Q: Can I control the current using external components with the DRV8818PWPR? A: Yes, the ISENSE pin can be used with an external current-sensing resistor to monitor and adjust the current.
16. Q: What is the purpose of the VCP pin? A: The VCP pin is used to connect a capacitor that powers the charge pump for gate drive voltage regulation.
17. Q: What is the maximum output current of the DRV8818PWPR? A: The DRV8818PWPR can provide up to 1.5A continuous current per coil under optimal conditions.
18. Q: Can I use the DRV8818PWPR for controlling motors in low-power applications? A: Yes, the SLEEP pin can be used to reduce power consumption when the device is not active.
19. Q: What is the purpose of the VREF2 pin? A: The VREF2 pin provides an additional voltage reference for motor current control in certain configurations.
20. Q: Can the DRV8818PWPR handle multiple motors at once? A: The DRV8818PWPR is designed for single motor control, but you can use multiple ICs to control more motors.
Summary
The DRV8818PWPR is a robust stepper motor driver with 28 pins, allowing for precise control over bipolar stepper motors. It supports various features such as current sensing, fault detection, and multiple control modes. The FAQ section should assist in understanding common queries about using the device in different applications.
