ISL6323B

Description

The ISL6323B dual PWM controller delivers high efficiency and tight regulation from two synchronous buck DC/DC converters. The ISL6323B supports hybrid power control of AMD processors which operate from either a 6-bit parallel VID interface (PVI) or a serial VID interface (SVI). The dual output ISL6323B features a multi-phase controller to support uniplane VDD core voltage and a single phase controller to power the Northbridge (VDDNB) in SVI mode. Only the multi-phase controller is active in PVI mode to support uniplane VDD only processors. A precision uniplane core voltage regulation system is provided by a two-to-four-phase PWM voltage regulator (VR) controller. The integration of two power MOSFET drivers, adding flexibility in layout, reduce the number of external components in the multi-phase section. A single phase PWM controller with integrated driver provides a second precision voltage regulation system for the North Bridge portion of the processor. This monolithic, dual controller with integrated driver solution provides a cost and space saving power management solution. For applications which benefit from load line programming to reduce bulk output capacitors, the ISL6323B features output voltage droop. The multi-phase portion also includes advanced control loop features for optimal transient response to load apply and removal. One of these features is highly accurate, fully differential, continuous DCR current sensing for load line programming and channel current balance. Dual edge modulation is another unique feature, allowing for quicker initial response to high di/dt load transients. The ISL6323B supports Power Savings Mode by dropping the number of phases to two when the PSI_L bit is set.