AU8020
8-phase digital VRM controller with PMBus for high-current processor power in servers and HPC systems.
Product Overview
Description
The AU8020 is an 8-phase digital VRM controller designed for high-current processor power delivery in servers and high-performance computing systems. It features PMBus communication for real-time monitoring and control of voltage, current, and temperature.
With support for up to 8 phases, the AU8020 can deliver 100A+ output current while maintaining excellent transient response and thermal distribution. The controller supports both Intel and AMD processor VID tables with automatic voltage regulation.
Advanced features include current balancing across phases, adaptive voltage positioning (AVP), and comprehensive protection (OVP, UVP, OCP, OTP). The AU8020 is available in a compact QFN-40 package and supports industrial temperature range.
Product Series
AU
Primary Application
Server CPU power
Key Features
- 8-phase operation for high current
- PMBus interface for monitoring/control
- Intel and AMD VID support
- Current balancing across phases
- Adaptive voltage positioning
- Comprehensive protection features
Specifications
| Input Voltage | 4.5V to 16V |
|---|---|
| Output Voltage | 0.5V to 2.0V |
| Max Current | 100A+ (8-phase) |
| Efficiency | Up to 96% |
| Interface | PMBus 1.3 |
| Package | QFN-40 |
Applications
Server CPU power
Electronic system design
High-performance computing
Electronic system design
FPGA core power
Electronic system design
ASIC power delivery
Electronic system design
Network processor power
Communication and interface
FAE Expert Insights
"The AU8020 is my top recommendation for high-current processor power designs. I've used it in multiple server designs delivering 100A+ with excellent results. The PMBus interface is a game-changer - you can monitor voltage, current, and temperature in real-time, enabling predictive maintenance and optimization. The current balancing works very well; I've measured <5% current mismatch between phases. One tip: pay attention to the current sense resistor selection - use low-TCR resistors for accurate current reporting. The transient response is excellent; I've seen <20mV undershoot on 50A load steps. Overall, a very capable controller at a competitive price point."
Excellent 8-phase VRM controller with PMBus for high-current applications
— David Liu, BeiLuo
Frequently Asked Questions
What processors are compatible with AU8020?
The AU8020 supports both Intel and AMD processor VID tables, making it compatible with a wide range of processors: (1) Intel Xeon Scalable processors - supports VR13 and VR14 specifications; (2) AMD EPYC processors - supports SVI2 and SVI3 interfaces; (3) High-performance FPGAs - can be configured for custom voltage requirements; (4) ASICs - programmable output voltage from 0.5V to 2.0V. The controller automatically detects the processor type and configures the appropriate VID table. For non-standard applications, the output voltage can be programmed through PMBus or external resistors.
AU8020 supports Intel Xeon, AMD EPYC, and custom voltage requirements.
How many phases does AU8020 support?
The AU8020 supports up to 8-phase operation natively. Each phase can deliver 15-20A depending on the power stage used. For 8-phase operation, you can achieve 120A+ output current with proper thermal design. The controller automatically balances current between phases to ensure even thermal distribution and optimal efficiency. Phase shedding is supported at light loads to improve efficiency. You can also use fewer phases (4, 6) for lower current applications, with unused PWM outputs left unconnected.
AU8020 supports 1-8 phases; use 8 phases for maximum current capability.
What is PMBus and how do I use it?
PMBus is a digital communication interface for power management: (1) Monitoring - read voltage, current, temperature, and power in real-time; (2) Control - adjust output voltage, enable/disable phases, configure protections; (3) Fault logging - record fault events for diagnostics; (4) Configuration - program VID tables, protection thresholds, and startup sequences. The AU8020 supports PMBus 1.3 with SMBus physical layer. Use standard PMBus commands or the Aurasemi GUI tool for configuration. Address selection is via external resistors or EEPROM.
PMBus enables real-time monitoring and control; use GUI tool or standard commands.
How do I set the output voltage?
Output voltage can be set multiple ways: (1) VID table - automatic based on processor SVID/PMBus commands for Intel/AMD processors; (2) PMBus - write VOUT_COMMAND to set voltage digitally; (3) External resistors - configure with resistor divider for fixed voltage; (4) Margining - adjust ±5% or ±10% for testing. The output voltage range is 0.5V to 2.0V. For processor applications, the VID table method is automatic. For non-processor applications, use PMBus or resistors. Voltage transitions are slew-rate controlled to prevent overshoot.
Use VID for processors, PMBus/resistors for non-processor applications.
What protection features are included?
The AU8020 includes comprehensive protection features: (1) Over-voltage protection (OVP) - shuts down if output exceeds threshold; (2) Under-voltage protection (UVP) - monitors for output droop; (3) Over-current protection (OCP) - per-phase and total current limits; (4) Over-temperature protection (OTP) - thermal shutdown at 150°C; (5) Input UVLO - prevents operation at low input voltage. All protections are programmable via PMBus with configurable thresholds and response actions (latch-off or retry). Fault status can be read through PMBus for diagnostics.
Comprehensive protection with programmable thresholds via PMBus.