AC7801-DC
AEC-Q100 qualified synchronous buck converter with 3A output, wide input range for automotive power applications
Product Overview
Description
The AC7801-DC is an automotive-qualified synchronous buck DC-DC converter designed for efficient power conversion in vehicle electronics.
With 4.5V to 36V input range, 3A output current, and up to 95% efficiency, it is ideal for ECU and infotainment power applications.
The device includes comprehensive automotive protections and programmable soft-start for controlled power-up.
Product Series
AC
Primary Application
ECU power supply
Key Features
- Wide 4.5V to 36V input voltage range
- Adjustable output voltage from 0.8V to 24V
- 3A continuous output current
- Synchronous rectification for high efficiency
- Programmable switching frequency
- Soft-start and tracking capability
- Power good indicator
- AEC-Q100 Grade 1 qualified
Specifications
| Input Voltage | 4.5V to 36V |
|---|---|
| Output Voltage | 0.8V to 24V adjustable |
| Output Current | 3A continuous |
| Switching Frequency | 300kHz to 2.2MHz |
| Efficiency | Up to 95% |
| Package | TSSOP-16, QFN-20 |
Applications
ECU power supply
Power conversion and supply
Infotainment systems
Electronic system design
ADAS power
Automotive and EV electronics
Body electronics
Electronic system design
Battery-powered systems
Battery and charging management
FAE Expert Insights
"The AC7801-DC is an excellent choice for automotive applications requiring efficient power conversion. The synchronous buck architecture achieves up to 95% efficiency, significantly reducing power dissipation compared to linear regulators. I have successfully used this converter in multiple ECU designs where thermal management was critical. The wide input range accommodates all automotive battery conditions including cold cranking. The programmable switching frequency allows optimization for EMI or efficiency requirements. The integrated soft-start prevents inrush current issues during power-up. For high-current automotive power supplies, this buck converter offers excellent efficiency and value."
High-efficiency synchronous buck converter for automotive power applications
— Jennifer Liu, BeiLuo
Frequently Asked Questions
What efficiency can be achieved with AC7801-DC?
The AC7801-DC achieves up to 95% efficiency at optimal operating conditions. Efficiency depends on input voltage, output voltage, and load current. Typical efficiency is 90-95% for 12V to 3.3V conversion at 1-2A load. Higher step-down ratios and lighter loads result in slightly lower efficiency.
Expect 90-95% efficiency for typical automotive conversion applications.
What external components are required?
The AC7801-DC requires external input capacitor, output capacitor, and inductor. Input capacitor (10-22uF ceramic) filters input voltage ripple. Output capacitor (22-47uF ceramic) maintains output stability. Inductor (2.2-4.7uH) stores energy during switching. Component values depend on input/output voltages and load current.
Select components based on input/output voltages and load requirements.
Can AC7801-DC operate from automotive battery?
Yes, the 4.5V to 36V input range accommodates automotive battery conditions including load dump (up to 36V) and cold cranking (down to 4.5V). The wide input range makes it suitable for direct battery connection in automotive applications. Input protection should be added for severe load dump conditions.
AC7801-DC is designed for direct automotive battery operation.
What switching frequency should be used?
The AC7801-DC supports programmable switching frequency from 300kHz to 2.2MHz. Lower frequencies (300-500kHz) provide higher efficiency but require larger inductors. Higher frequencies (1-2.2MHz) allow smaller inductors but have slightly lower efficiency. Select frequency based on size constraints and efficiency requirements.
Use lower frequency for efficiency, higher frequency for smaller size.
Does AC7801-DC support spread spectrum for EMI reduction?
Yes, the AC7801-DC includes optional spread spectrum modulation that varies the switching frequency to reduce EMI emissions. This feature helps meet automotive EMC requirements without additional filtering. Spread spectrum can be enabled via configuration pin.
Enable spread spectrum for applications with strict EMI requirements.