AC7801-MOTOR
AEC-Q100 qualified BLDC motor driver with integrated gate drive and sensorless commutation for automotive fans
Product Overview
Description
The AC7801-MOTOR is an automotive-qualified brushless DC motor driver featuring integrated gate drive and sensorless commutation.
With 6V to 60V supply range, 3A peak current, and integrated protection features, it is ideal for automotive cooling fans and pumps.
The device includes sensorless BEMF detection, programmable speed control, and comprehensive fault protection.
Product Series
AC
Primary Application
Engine cooling fans
Key Features
- Wide 6V to 60V supply voltage range
- 3A continuous output current
- Integrated 3-phase gate drivers
- Sensorless BEMF commutation
- Programmable speed control via PWM
- Over-current and over-temperature protection
- Open-load and locked-rotor detection
- AEC-Q100 Grade 1 qualified
Specifications
| Supply Voltage | 6V to 60V |
|---|---|
| Output Current | 3A continuous, 5A peak |
| Gate Drive Voltage | 12V typical |
| PWM Frequency | Up to 50kHz |
| Commutation | Sensorless BEMF detection |
| Package | TSSOP-20, QFN-32 |
Applications
Engine cooling fans
Electronic system design
HVAC blower motors
Motor drive and control systems
Water pump motors
Motor drive and control systems
Oil pump motors
Motor drive and control systems
Auxiliary fan motors
Motor drive and control systems
FAE Expert Insights
"The AC7801-MOTOR is my go-to solution for automotive BLDC fan and pump applications. The integrated sensorless commutation eliminates the need for Hall sensors, reducing system cost and improving reliability. I have successfully used this driver in multiple engine cooling fan and HVAC blower projects. The 6-60V supply range covers all automotive battery conditions including load dump. The integrated protection features including locked-rotor detection prevent motor damage under fault conditions. The programmable PWM speed control allows flexible system design. For cost-sensitive automotive motor applications, this driver offers excellent value compared to discrete solutions."
Integrated BLDC driver with sensorless commutation for reliable automotive fan control
— Dr. Michael Chen, BeiLuo
Frequently Asked Questions
How does sensorless commutation work?
The AC7801-MOTOR uses Back-EMF (BEMF) sensing for sensorless commutation. As the motor rotates, the permanent magnets induce voltage in the stator windings. The driver monitors the BEMF zero-crossings to determine rotor position and commutates the motor at optimal timing. This eliminates the need for Hall effect sensors, reducing cost and improving reliability. The driver includes automatic startup routines to reliably start the motor from standstill.
Sensorless commutation reduces cost and improves reliability for most BLDC applications.
What is the maximum PWM frequency?
The AC7801-MOTOR supports PWM frequencies up to 50kHz for motor speed control. The high-frequency PWM allows quiet operation and smooth speed control. The gate drive circuits are optimized for efficient switching at these frequencies. Programmable dead-time prevents shoot-through conditions during PWM switching. The PWM input accepts 3.3V or 5V logic levels for easy interface with automotive MCUs.
50kHz PWM supports quiet operation. Select lower frequencies for higher efficiency at high power.
Does AC7801-MOTOR support locked-rotor protection?
Yes, the AC7801-MOTOR includes locked-rotor detection and protection. If the motor fails to start or becomes mechanically blocked, the driver detects abnormal current patterns and shuts down to prevent motor and driver damage. The fault condition is reported via the diagnostic output. Automatic retry with backoff timing allows recovery from temporary fault conditions.
Locked-rotor protection is essential for reliable automotive fan and pump applications.
What thermal management is required?
The AC7801-MOTOR thermal management depends on operating conditions and package selection. The TSSOP-20 package requires approximately 50mm² copper area for 3A continuous operation at 85°C ambient. The QFN-32 with exposed pad provides better thermal performance with adequate PCB copper. The driver includes over-temperature protection with automatic shutdown and recovery. Thermal vias under the exposed pad improve heat dissipation.
Provide adequate PCB copper area based on continuous current and ambient temperature.
Can AC7801-MOTOR drive different motor configurations?
The AC7801-MOTOR supports various 3-phase BLDC motor configurations including Y-connected and Delta-connected windings. The driver automatically adapts to different motor parameters through external resistor configuration. Motor pole pair configuration is programmable via external pins. This flexibility allows the same driver to be used with different motor types across various automotive applications.
AC7801-MOTOR supports standard 3-phase BLDC configurations. Contact LiTong for specific motor compatibility.