Digital multiphase PWM controllers with AVSBus; current control to 450A

November 01, 2016 // By Graham Prophet
Intersil has assembled a complete controller and smart power stage configuration using a technique it calls synthetic current control, that delivers up to 450A load to any processor, ASIC or FPGA.

Intersil has added 12 digital multiphase controllers and a companion smart power stage, including the first digital solution with an Adaptive Voltage Scaling Bus (AVSBus). These digital controllers provide up to seven phases assignable in any combination across two outputs, and combine with smart power stages to provide a scalable solution from 10A to 450A. The result is enhanced power optimization and more energy-efficient networking and communications infrastructure equipment.


AVSBus joins the PMBus v1.3 specification and features a 50 MHz high-speed bus that connects directly to the processor to communicate telemetry data and deliver efficiency savings through adaptive voltage positioning. Intersil’s DC/DC controllers and ISL99227 60A smart power stage support demanding CPU core voltages, memory, and auxiliary power rails, enabling power designers to customize their solution to meet any rail requirements. Watch a video on this digital multiphase power solution here;


The digital multiphase family comprises three groups of controllers. The ISL68137 and ISL68134 controllers utilize the AVSBus to power and communicate with ARM-based processors in network routers, switches, servers, storage, and wireless telecom equipment. Two general-purpose controllers (ISL68127 and ISL68124) power network processors, FPGAs, SoCs and graphics accelerators. And eight controllers (ISL69147/44, ISL69137/34, ISL69128/27 and ISL69125/24) add a secondary high-speed interface (SVID or SVI2) to power the latest Intel and AMD processors in cloud computing applications.


The ISL681xx and ISL691xx controllers integrate a high performance digital engine featuring a synthetic current control architecture that tracks each phase current with zero latency. This allows the device to respond to any load transient with precise current and voltage positioning, and 30% less capacitance than competitive devices. Synthetic current control also makes it possible to develop high reliability systems using all-ceramic capacitors.


Engineers are able to realize the flexibility and benefit of digital control through Intersil’s PowerNavigator GUI software tool. PowerNavigator connects to development boards communicating across PMBus and AVSBus, allowing engineers to set up and control all parameters, optimize efficiency via precise current thresholds for adding/dropping phases, and adjust the loop tuning. PowerNavigator eliminates board rework as designs are completed with on-the-fly changes for stability tuning and optimization. The final configuration is saved to non-volatile memory.


Controller pricing in the table on the following pages; the ISL99227 smart power stage is supplied in a 5 x 5 mm, 32-lead QFN package and is priced at $5.21(1000). Development boards are also available




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