The TB6568KQ is a high – performance full – bridge driver IC designed specifically for controlling brushed DC motors. It is developed by Toshiba and offers a wide range of features that make it suitable for various applications requiring precise motor control.
1. Power Supply and Output Capability
- Power Supply Range: The TB6568KQ can operate with a wide power supply voltage range from 10V to 45V (with a maximum rating of 50V). This flexibility allows it to be used in different power systems, from low – voltage battery – powered devices to higher – voltage industrial applications.
- Output Current: It can deliver a maximum output current of up to 3A. This high – current capacity enables it to drive relatively large – power brushed DC motors, providing sufficient torque for the motor to operate effectively.
- Low On – Resistance: The typical output ON – resistance of the TB6568KQ is 0.55Ω. A low on – resistance helps to reduce power dissipation in the form of heat during operation, improving the overall efficiency of the motor – driving system.
2. Motor Control Modes
- Four Operating Modes: The chip supports four distinct operating modes, which are selected through the IN1 and IN2 input pins. These modes include Clockwise (CW) rotation, Counter – Clockwise (CCW) rotation, Short Brake, and Stop.
- Clockwise and Counter – Clockwise Rotation: By setting the appropriate logic levels on the IN1 and IN2 pins, the TB6568KQ can control the direction of the brushed DC motor’s rotation. This is useful in applications such as robotic arms, conveyor belts, and electric vehicles where the motor needs to rotate in both directions.
- Short Brake: In the short – brake mode, the motor terminals are short – circuited, which quickly stops the motor’s rotation. This mode is beneficial in applications that require rapid braking, such as in some precision – positioning systems.
- Stop: The stop mode simply cuts off the power supply to the motor, bringing it to a halt.
3. PWM Speed Control
- Pulse – Width Modulation (PWM): The TB6568KQ utilizes PWM control to regulate the speed of the brushed DC motor. By adjusting the duty cycle of the PWM signal applied to the EN (Enable) pin, the average voltage applied to the motor can be varied. A higher duty cycle results in a higher average voltage and a faster motor speed, while a lower duty cycle leads to a slower speed. This provides a precise and efficient way to control the motor’s rotational speed, which is essential in applications like variable – speed fans, pumps, and servo – controlled systems.
4. Protection Features
- Over – Current Shutdown (ISD): The chip is equipped with an over – current shutdown circuit. If the output current exceeds a certain predefined threshold, the ISD circuit will automatically shut down the output to protect the chip and the motor from damage caused by excessive current. This is crucial in preventing overheating and potential burnout of the motor or the driver IC.
- Over – Voltage Shutdown (VSD): The over – voltage shutdown circuit monitors the power supply voltage. If the voltage exceeds the maximum allowable limit (e.g., above 50V), the VSD circuit will trigger and shut down the device to safeguard it from over – voltage damage.
- Thermal Shutdown (TSD): The TB6568KQ has a thermal shutdown circuit that monitors the internal temperature of the chip. When the temperature rises above a safe operating limit, the TSD circuit will turn off the output to prevent the chip from overheating, ensuring its long – term reliability.
- Under – Voltage Lockout (UVLO): The under – voltage lockout circuit ensures that the chip operates only when the power supply voltage is within a valid range. If the voltage drops below a certain level, the UVLO circuit will disable the output to prevent improper operation and potential damage to the motor and the chip.
5. Dead – Time Control
- Shoot – Through Prevention: To prevent a short – circuit condition known as shoot – through, the TB6568KQ incorporates dead – time control. Shoot – through occurs when both the high – side and low – side MOSFETs in the full – bridge configuration conduct simultaneously, which can cause a large current spike and damage the chip. The dead – time control ensures that there is a short period of time when both MOSFETs are turned off before one of them is turned on, thus preventing shoot – through and improving the safety and reliability of the motor – driving system.
6. Application Areas
- Consumer Electronics: In consumer products such as electric toys, home appliances (e.g., vacuum cleaners, electric toothbrushes), and small – scale robotic devices, the TB6568KQ can be used to control the movement of brushed DC motors, providing reliable and efficient motor control.
- Industrial Automation: In industrial settings, it can be applied to control motors in conveyor systems, small – scale manufacturing equipment, and robotic arms, enabling precise positioning and movement control.
- Automotive Applications: In some automotive subsystems, such as power windows, windshield wipers, and small – sized actuators, the TB6568KQ can be used to drive brushed DC motors due to its high – performance and protection features.
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