DRV8870DDAR Detailed explanation of pin function specifications and circuit principle instructions
The DRV8870DDAR is part of the Texas Instruments brand. It is a motor driver IC designed for controlling motors in various applications, such as stepper motors, DC motors, and other types of actuators. This IC is often used in power management circuits and motor control systems due to its advanced features.
Package Type
The DRV8870DDAR comes in a SOIC-8 (Small Outline Integrated Circuit) package. This package has 8 pins, and each pin has a specific function. Below is the detailed explanation of the pin functions for this IC.
Pin Function Specification and Circuit Principle
Pinout of DRV8870DDAR (SOIC-8 Package) Pin No. Pin Name Function Description 1 VREF Reference voltage input (for setting motor current limits and other control parameters). 2 IN1 Logic input that controls the direction of the motor. This pin is connected to a logic signal for driving. 3 IN2 Logic input that controls the motor driver in combination with IN1. Typically used for forward/reverse control. 4 nFAULT Fault output signal. This pin is active low when there is a fault condition, like overcurrent or overtemperature. 5 GND Ground pin. This is the common reference point for all signals and voltage supplies. 6 VM Motor supply voltage input. This pin supplies the voltage for the motor. 7 OUT2 Motor drive output pin. This pin connects to one of the motor terminals. 8 OUT1 Motor drive output pin. This pin connects to the other motor terminal.Detailed Pin Functions and Usage
VREF (Pin 1): This pin allows the user to input a reference voltage to control the current limit for the motor. By adjusting the voltage at this pin, you can set how much current the motor can draw. IN1 (Pin 2): This is the input for controlling the direction of the motor. It is typically driven by a microcontroller or other logic circuit to determine the motor’s direction. IN2 (Pin 3): This input also controls the motor direction, but works in conjunction with IN1. A typical setup uses both IN1 and IN2 to control forward/reverse operation of the motor. nFAULT (Pin 4): The nFAULT pin indicates any fault condition in the motor driver circuit, such as overcurrent, overheating, or undervoltage. When a fault occurs, this pin will go low (logic 0) to signal an error state. GND (Pin 5): The GND pin is the common ground for the IC and all external components. This pin ensures proper operation by providing a reference voltage level. VM (Pin 6): The VM pin is the input for the motor power supply. This voltage is used to drive the motor. It should be properly regulated to provide stable motor operation. OUT2 (Pin 7): OUT2 is one of the two outputs that drive the motor. This pin connects to one terminal of the motor, and the motor current will flow through this pin when the motor is operating. OUT1 (Pin 8): OUT1 is the second motor drive output, which connects to the other terminal of the motor. It works in tandem with OUT2 to provide the required current to the motor.Pin Function FAQ (20 Common Questions)
What is the function of the VREF pin on the DRV8870DDAR? The VREF pin sets the current limit for the motor. It is used to regulate the motor’s maximum current draw. How do IN1 and IN2 control motor direction? IN1 and IN2 work together to control the direction. For example, IN1 high and IN2 low may drive the motor in one direction, while IN1 low and IN2 high drives the motor in the opposite direction. What does the nFAULT pin indicate? The nFAULT pin indicates any fault condition in the driver, such as overcurrent, overtemperature, or undervoltage. Can the motor run without the VREF pin connected? No, the VREF pin is essential for current control, and without it, the motor will not run properly. What is the maximum motor supply voltage for VM? The maximum voltage for VM is typically specified in the datasheet, but it is essential not to exceed the recommended operating voltage to prevent damage. What type of fault conditions are detected by the nFAULT pin? Fault conditions detected include overcurrent, thermal shutdown, and undervoltage. Can IN1 and IN2 be driven by logic-level signals? Yes, IN1 and IN2 are designed to be controlled by logic-level signals from a microcontroller or digital circuit. How do I know when the motor has a fault? When a fault occurs, the nFAULT pin will go low, signaling that the motor driver has encountered an issue. What is the minimum voltage required for VM to operate the motor? The minimum voltage is specified in the datasheet and depends on the motor's requirements, but typically it is around 4V or higher. How can I configure the motor driver for stepper motors? For stepper motors, the input pins (IN1, IN2) need to be controlled in a sequence that corresponds to the stepping pattern of the motor. Can I use this IC for high-power motors? The DRV8870DDAR is suitable for moderate-power motors. For high-power motors, ensure that the current and voltage ratings are within the specified limits. What happens if the motor draws too much current? If the motor exceeds the current limit set by the VREF pin, the DRV8870DDAR will enter a fault state, and the nFAULT pin will go low. What is the purpose of GND? GND is the common reference for the motor driver and other components. It ensures that the IC and connected circuits operate with a stable reference. How do I connect the motor to the DRV8870DDAR? The motor terminals should be connected to OUT1 and OUT2. Ensure that the power supply is connected to VM, and the logic inputs are connected to IN1 and IN2. Can the DRV8870DDAR drive more than one motor? The DRV8870DDAR can drive one motor per chip. For multiple motors, additional chips would be needed. What type of motors can I use with the DRV8870DDAR? It is suitable for driving DC motors, stepper motors, and other types of small motors within the voltage and current limits. What is the function of OUT1 and OUT2? OUT1 and OUT2 are the motor drive outputs, where the current flows to the motor. These pins deliver the required voltage to operate the motor. What is the significance of the thermal shutdown feature? Thermal shutdown protects the IC from overheating. If the temperature exceeds a safe limit, the IC will shut down to prevent damage. How can I reset the fault condition indicated by nFAULT? Once the fault condition is cleared, you can reset the IC by toggling the inputs or by removing and reapplying power. Is it necessary to add external components to the DRV8870DDAR? Depending on the application, external components such as capacitor s, resistors, and protection diodes might be needed for optimal performance and reliability.This explanation provides a comprehensive understanding of the DRV8870DDAR IC, including its pin functions, usage, and common questions.