AU8110
High-efficiency synchronous buck converter with 4.5V to 60V input range and 3A output current.
Product Overview
Description
The AU8110 is a high-efficiency synchronous buck converter designed for industrial and automotive applications. It accepts a wide input voltage range from 4.5V to 60V, making it suitable for 12V, 24V, and 48V systems.
With integrated high-side and low-side MOSFETs, the AU8110 delivers up to 3A continuous output current with peak efficiency of 96%. The adjustable switching frequency (100kHz to 2.5MHz) allows optimization for size or efficiency.
Protection features include over-current protection, thermal shutdown, and input undervoltage lockout. The AU8110 is available in a thermally enhanced QFN-20 package and supports industrial and automotive temperature ranges.
Product Series
AU
Primary Application
Industrial control systems
Key Features
- Wide 4.5V to 60V input range
- 3A continuous output current
- Synchronous rectification
- Adjustable switching frequency
- Programmable soft-start
- Power-good indicator
Specifications
| Input Voltage | 4.5V to 60V |
|---|---|
| Output Voltage | 0.8V to 0.9×VIN |
| Output Current | 3A continuous |
| Efficiency | Up to 96% |
| Switching Frequency | 100kHz to 2.5MHz |
| Package | QFN-20 |
Applications
Industrial control systems
Industrial automation and control
Automotive electronics
Automotive and EV electronics
Telecom equipment
Electronic system design
Battery-powered systems
Battery and charging management
Point-of-load regulation
Power conversion and supply
FAE Expert Insights
"The AU8110 is my go-to buck converter for industrial applications requiring wide input range. The 60V maximum input handles 48V systems with margin, and the 96% efficiency keeps thermal design manageable. I've used it in 24V industrial systems with excellent results. The adjustable frequency is useful - I typically run at 500kHz for good efficiency with reasonable component size. The integrated MOSFETs save BOM cost and board space. One design tip: use a good ceramic input capacitor close to the IC to handle switching current ripple. The thermal performance is good with proper copper area. A reliable workhorse converter."
Wide input range buck converter with excellent efficiency for industrial applications
— David Liu, BeiLuo
Frequently Asked Questions
What inductor value should I use?
Inductor selection affects ripple current, efficiency, and transient response: (1) Ripple current - typically 20-40% of output current; (2) Inductance value - L = (VIN - VOUT) × D / (ΔIL × fSW); (3) Saturation current - must exceed peak inductor current with margin; (4) DCR - lower DCR improves efficiency; (5) Core material - ferrite for high frequency, powdered iron for cost. For AU8110 at 500kHz with 24V input and 5V/3A output: L ≈ 10-15μH. Use shielded inductors for EMI-sensitive applications. The datasheet provides recommended inductor part numbers from major suppliers.
Calculate inductance for 20-40% ripple current; ensure adequate saturation margin.
How do I optimize efficiency?
To maximize buck converter efficiency: (1) Switching frequency - lower frequency reduces switching losses; (2) Inductor DCR - use low-resistance inductor; (3) Input/output capacitors - use low-ESR ceramic capacitors; (4) Layout - minimize switching loop area, use ground plane; (5) Light load - enable pulse-skipping or burst mode if available; (6) MOSFETs - AU8110 uses optimized integrated MOSFETs. Efficiency varies with load - typically peaks at 50-75% load. For battery applications, consider light-load efficiency. Measure efficiency under actual operating conditions including temperature.
Lower frequency, low-DCR inductor, good layout for best efficiency.
What input capacitor is recommended?
The input capacitor handles switching current ripple: (1) Ceramic capacitors - use 10-22μF X5R or X7R ceramic close to the IC; (2) Voltage rating - at least 1.5x maximum input voltage; (3) RMS current rating - must handle input ripple current; (4) ESR - lower is better for ripple reduction; (5) Additional bulk - add 100μF electrolytic for high current applications. Place capacitors as close as possible to the VIN and GND pins. The loop area formed by input capacitor, IC, and ground should be minimized.
Use 10-22μF ceramic close to IC; add bulk capacitor for high current.
Can AU8110 operate at 85°C ambient?
Yes, the AU8110 supports industrial temperature range (-40°C to +85°C). At 85°C ambient with 3A output current, thermal management is important: (1) Use 500mm² or more copper area; (2) Connect thermal pad to ground plane with multiple vias; (3) Ensure adequate airflow if possible; (4) Reduce switching frequency slightly to lower losses; (5) Consider derating output current at high ambient. The thermal shutdown activates at 160°C junction temperature. Monitor actual operating temperature in your application.
Yes with proper thermal design; use adequate copper area and vias.
What is the power-good indicator used for?
The power-good (PG) indicator is an open-drain output that signals when the output voltage is within regulation: (1) PG goes high when output reaches 95% of target voltage; (2) PG goes low if output drops below 90% or exceeds 110% of target; (3) Use for power sequencing - delay startup of downstream converters until primary rail is stable; (4) Connect to enable pins of other regulators for automatic sequencing; (5) Can be used for system reset generation. The PG output requires an external pull-up resistor (typically 10kΩ to 3.3V or 5V). This feature simplifies multi-rail power system design.
Use PG for power sequencing and system reset generation.