FN9012

ISL6562 TM Data Sheet March 2001 File Number 9012 Microprocessor CORE Voltage Regulator Two-Phase Buck PWM Controller The ISL6562 two-phase current mode, PWM control IC together with companion gate drivers, the HIP6601A, HIP6602A, HIP6603A or HIP6604 and MOSFETs provides a precision voltage regulation system for advanced microprocessors. Two-phase power conversion is a marked departure from earlier single phase converter configurations previously employed to satisfy the ever increasing current demands of modern microprocessors. Multi-phase converters, by distributing the power and load current results in smaller and lower cost transistors with fewer input and output capacitors. These reductions accrue from the higher effective conversion frequency with higher frequency ripple current due to the phase interleaving process of this topology. For example, a two phase converter operating at 350kHz per phase will have a ripple frequency of 700kHz. Moreover, greater converter bandwidth of this design results in faster response to load transients. Outstanding features of this controller IC include programmable VID codes from the microprocessor that range from 1.050V to 1.825V with an accuracy of ±0.8%. Pull up currents on these VID pins eliminates the need for external pull up resistors. Another feature of this controller IC is the PWRGD monitor circuit which is held low until the CORE voltage increases, to within 18% of the programmed voltage. Over-voltage, 24% above programmed ...