Three rail multi-phase dc-dc controller meets Intel IMVP 9.2

AOZ71137QI is a three rail seven-phase controller for CPUs that has: up to four phases for the core voltage (‘IA domain’), up to two phases for graphics (‘GT domain’) and one phase for the auxiliary (‘SA domain’) output.

To save power at light load, the CPU output can phase-shed for three, two or one-phase operation, and the graphics output can drop to a single phase.

It operates in a variable frequency hysteretic peak current mode for fast transient response, which is combined with a proprietary phase current sensing scheme.

“The control loop enhances light-load efficiency by seamlessly entering DCM [discontinuous current mode],” according to the company. Autonomous phase management also assures optimized efficiency and power loss during light load with single-phase DCM mode.” Quiescent current is 3.7mA for a 2 + 1 +1 configuration in PS0 mode, it added.

As a controller, the IC provides PWM waveforms to external power mosfets via external gate drivers – the company has its own mosfet+driver combo modules (see diagram). “These devices allow designers to meet complete Vcore power requirements with robustness along with 30V breakdown voltage and UIS testing,” claims AOS.

An SMBus interface is available for configuration, and application-specific tuning during development for which the AOS has a programming GUI.

While internal ram is used during development, “the controller also provides MTP to store register settings once the configuration is finalised”, said AOS – MTP = re-programmable non-volatile memory for “more than 10x configuration changes”.

Protection and warning are provided for under-voltage, over-voltage, over-current and over-temperature. Protection behavior can be programmed through the SMBus, which also provides a channel for real-time telemetry covering Vin, Vout, temperature, output currents, power states, and certain IC pin states.

Packaging is 6x6mm 52pad QFN and operation is over junction temperatures from -40 to +125°C.