ON Semiconductor has introduced the first six-phase Pulse Width Modulation (PWM) controllers. The ADP4000 and ADP4100 satisfy the demanding performance requirements of Intel’s VR11.1 specification and enable energy efficient motherboard and graphics card designs for servers and high-end desktop computers.
The ADP4000 and ADP4100 utilize features of VR11.1, the new desktop/server spec from Intel for 2008 desktop and server platforms, to conserve power during light-loading in order to save energy and generate less heat than earlier industry solutions. Dynamic VID transitions adjust both the processor voltage and processor frequency to switch between power/performance states. IMON (Current Monitoring) is required by VR11.1 for power management features of the processor.
The ADP4000 and ADP4100 possess various protection and monitoring features. Current limit protection is available with delayed latch-off function. This allows for inherent per-phase protection against faulty components. Power Good monitoring is also present. High pull-up indicates that the voltage is within normal limits.
The Fast Enhancement PWM (FEPWM) architecture is an improved version of EPWM to achieve extremely fast turn-on during transients yet preserves the clocking system for stability. FEPWM also maintains interleaving between phases even during transients for input filter power dissipation reduction. PWM clocking is still used for steady-state operation.
The ADP4000 includes a PMBus programmable digital interface that allows designers to optimize compensation and control performance, saving design-time and decreasing time to market. PMBus, which is based on SMBus, is an open standard for communicating power information over a digital interface. It is intended to work with all types of converters. Several functions can be programmed over PMBus including output voltage (VID code), output voltage offset for over-clocking, and current limit thresholds. The ADP4000 supports 25 PMBus-defined commands and 38 manufacturer-specific commands.
ON Semiconductor, www.onsemi.com
