The Allegro MicroSystems A2919SLBTR-T is a part of the A2919 family of stepper motor drivers, designed for use in applications such as precision motion control, robotics, and other systems requiring efficient driving of bipolar stepper motors.
Here’s a detailed guide on the A2919SLBTR-T:
Overview:
The A2919SLBTR-T is a dual H-bridge driver that can operate in a stepper motor configuration with microstepping capability, designed for controlling the motion of stepper motors in both low- and high-power applications. It features advanced current regulation to ensure the motor operates efficiently and quietly.
Key Features:
1. Dual H-Bridge Driver:
- It includes two H-bridge output stages that allow it to drive bipolar stepper motors with ease.
2. Microstepping Capability:
- The A2919SLBTR-T can drive stepper motors with microstepping, offering up to 1/16th step resolution.
- This allows for smooth motor motion and precise positioning, which is essential in applications like 3D printers, CNC machines, and other motion control systems.
3. Current Regulation:
- The device features fixed off-time current regulation, which improves motor efficiency and reduces power loss.
- Current control helps minimize heat generation in the motor, resulting in quieter operation and less thermal stress.
4. Voltage Supply Range:
- The A2919SLBTR-T operates from a supply voltage range of 8 V to 35 V, which makes it suitable for a wide variety of applications and motor sizes.
5. Output Current:
- It can handle continuous output currents up to 1.5 A (depending on thermal conditions) and up to 2.5 A peak. This high current capability ensures that it can drive motors with significant power requirements.
6. Thermal Protection:
- The A2919SLBTR-T includes over-temperature and overcurrent protection to prevent damage in the event of excessive heat or load.
7. Integrated Protection Features:
- Under-voltage lockout and overcurrent protection are included to protect the IC and the motor from abnormal operating conditions.
8. Low Power Consumption:
- Low standby current ensures minimal power loss when the motor is idle.
9. PWM Control:
- The driver uses Pulse Width Modulation (PWM) for current regulation, which allows for efficient power delivery and reduces the chance of motor vibration.
10. Package:
- The device comes in a 28-pin TSSOP package, making it compact and suitable for space-constrained designs.
Electrical Characteristics:
- Supply Voltage (Vcc): 8 V to 35 V
- Motor Voltage (VM): 8 V to 35 V
- Logic Supply Voltage (Vcc): 4.5 V to 5.5 V
- Operating Current: 1.5 A (continuous), 2.5 A (peak)
- Microstep Resolution: Up to 1/16th microstep
- Control Input Voltage: Typically 0 V to 5 V
- Current Regulation: Fixed off-time
- Thermal Shutdown: Integrated thermal protection
Applications:
1. Stepper Motor Drives:
- The A2919SLBTR-T is ideal for driving bipolar stepper motors in industrial and consumer applications where smooth and efficient motor control is required.
2. Robotics:
- In robotic systems, it can be used to control precise motor movements for actuators, enabling accurate positioning.
3. 3D Printers:
- The microstepping capability is especially valuable in 3D printing for precise control of the motors driving the print bed and extruder.
4. CNC Machines:
- In CNC applications, the A2919SLBTR-T can provide smooth motion control, enabling the precise movement of tooling.
5. Automation Systems:
- Suitable for use in automated machinery requiring precise, energy-efficient motor control.
Additional Features:
- Stepping Mode Control:
- Supports full-step, half-step, and microstepping modes, providing flexibility depending on the motor's resolution and the application's needs.
- External Control Pins:
- The device features control pins for enabling and disabling the outputs, changing the direction of the motor, and selecting the stepping mode.
- Phase-to-Phase Short Circuit Protection:
- It includes mechanisms to detect and protect against short circuits between the motor phases.
Pin Configuration:
The A2919SLBTR-T comes in a 28-pin TSSOP package, with key pins including:
- STEP (step pulse input)
- DIR (direction control)
- ENABLE (enable motor driver outputs)
- VREF (current reference)
- PHASE (motor phase outputs)
Typical Application Circuit:
·Power Supply: A regulated supply capable of providing 8V to 35V to the motor (VM) and a 5V supply for logic and control (VCC).
·Current Sense Resistor: Used to set the motor current limit via the VREF pin, enabling adjustable current regulation.
·Microstep Select Pins: These are used to set the microstepping resolution.
Thermal Management:
The A2919SLBTR-T includes features to ensure safe operation under high-current conditions:
·Thermal shutdown protection prevents overheating of the IC and the motor.
·An external heatsink or adequate PCB layout with heat dissipation may be necessary in high-power applications.
Conclusion
The A2919SLBTR-T is a versatile and efficient motor driver for driving bipolar stepper motors with advanced features like microstepping, fixed off-time current regulation, and thermal protection. It is a great choice for applications requiring precise motion control, high efficiency, and quiet operation, such as robotics, CNC machines, and 3D printers.
