Aurasemi Power Management ICs

Selecting a VRM controller requires matching the controller capabilities to your processor requirements: (1) Current capability - choose a controller supporting 20-30% more current than your processor's maximum TDP

(2) Voltage requirements - ensure the controller supports your processor's VID table and voltage regulation specifications

(3) Phase count - more phases provide better transient response and thermal distribution

(4) Features - consider PMBus for monitoring, current sensing for protection, and advanced control algorithms for efficiency. The AU80xx series supports Intel and AMD processor requirements with configurable phase counts from 4 to 8 phases.

Match VRM controller current capability and features to your processor requirements.

Aurasemi DC-DC converters achieve high efficiency through advanced control algorithms and optimized power stage design: (1) Peak efficiency - typically 94-96% at mid-to-heavy loads

(2) Light-load efficiency - >80% at 10% load using advanced light-load modes

(3) Factors affecting efficiency - input/output voltage ratio, load current, switching frequency, and inductor selection

(4) Thermal impact - higher efficiency reduces heat generation, simplifying thermal design. The AU81xx series uses synchronous rectification and adaptive dead-time control to minimize losses. For battery-powered applications, the low quiescent current (<50μA) extends battery life.

Expect 94-96% peak efficiency; consider light-load requirements for battery applications.

Aurasemi power management ICs include comprehensive protection: (1) Over-voltage protection (OVP) - shuts down output if voltage exceeds threshold

(2) Under-voltage protection (UVP) - monitors input and output voltages

(3) Over-current protection (OCP) - limits current to safe levels

(4) Over-temperature protection (OTP) - thermal shutdown at 150°C

(5) Short-circuit protection - hiccup mode or latch-off. These protections ensure safe operation under fault conditions and prevent damage to the IC and load. Protection thresholds are programmable through PMBus or external components.

Comprehensive protection including OVP, UVP, OCP, OTP, and short-circuit protection.

Parallel operation for higher output current: (1) Current sharing - use droop compensation or active current balancing

(2) Phase interleaving - reduces input/output ripple

(3) Master-slave configuration - one controller manages multiple power stages

(4) Synchronization - lock switching frequencies to prevent beat frequencies. The AU8020 supports 8-phase operation natively. For even higher current, multiple AU8020 controllers can be synchronized. Proper layout is critical - ensure balanced current paths and shared feedback sensing. Contact LiTong FAE for high-current design support.

Use multi-phase or parallel configuration with current sharing for high current.

Switching frequency selection involves trade-offs: (1) Higher frequency (500kHz-2MHz) - smaller inductors and capacitors, faster transient response, but higher switching losses

(2) Lower frequency (100kHz-500kHz) - higher efficiency, lower EMI, but larger passive components

(3) Aurasemi converters support 100kHz to 2.5MHz switching

(4) Synchronization - external clock input for multi-rail systems. For automotive applications, avoid AM band (530-1700kHz) to prevent interference. The optimal frequency depends on input/output voltages, current, and size/efficiency requirements.

Select 500kHz-1MHz for general applications; higher for compact designs.

Aurasemi DC-DC converters support flexible switching frequencies from 100kHz to 2.5MHz. Lower frequencies (100-300kHz) provide higher efficiency but require larger inductors. Higher frequencies (1-2.5MHz) enable compact designs with smaller passive components but have slightly lower efficiency. The optimal frequency depends on your specific requirements for efficiency, size, and EMI. For automotive applications, avoid the AM band (530-1700kHz) to prevent interference.

Select 100-500kHz for high efficiency, 1-2MHz for compact designs.

Inductor selection involves several considerations: (1) Inductance value - calculate based on input/output voltages, switching frequency, and desired ripple current (typically 20-40% of output current)

(2) Saturation current - must exceed peak inductor current with margin (typically 1.3-1.5x)

(3) DCR - lower DCR improves efficiency but increases size/cost

(4) Core material - ferrite for high frequency, powdered iron for cost-sensitive applications

(5) Shielding - use shielded inductors for EMI-sensitive applications. The datasheet provides recommended inductor part numbers from major suppliers.

Calculate inductance for 20-40% ripple; ensure adequate saturation margin.