LM2720 Datasheet | Texas Instruments

OBSOLETE .ti. SNVS081B - MAY 2004 - REVISED MARCH 2009 LM2720 5-Bit Programmable, High Frequency Multi-phase PWM Controller Check for Samples: LM2720 Features - 2 Ultra Fast Load Transient Response - Enables All Surface-Mount-Design - Selectable 2, 3, 4 Phase Operation - Clock Frequency from 40 k Hz to 10 MHz - Precision Load Current Sharing - 5-bit Programmable from 3.5V to 1.3V - VID Code patible to VRM 8.X Specification - Output Voltage is 2.0V for VID Code 11111 - Selectable Internal or External Clock - Digital 16-Step Soft Start - Input Under-Voltage Lock-Out, Over-Current Protection - Open-Drain Power Good Signal Output APPLICATIONS - Servers and Workstations - High Current, Ultra-Fast Transient Microprocessors DESCRIPTION The LM2720 provides an attractive solution for power supplies of high power microprocessors exhibiting ultra fast load transients. pared to a conventional single-phase supply, an LM2720 based multi-phase supply distributes the thermal and electrical loading among ponents in multiple phases and greatly reduces the corresponding stress in each ponent. The LM2720 can be programmed to control either a 3-phase converter or a 4-phase converter. Phase shift among the phases is 120° in the case of three phase and 90° with four-phase. Because the power channels are out of phase, there can be significant ripple cancellation for both the input and output current, resulting in reduced input and output capacitor size. Due to the nominal operating frequency of 2 MHz per phase, the size of the output inductors can be greatly reduced which results in a much faster load transient response and a dramatically shrunk output capacitor bank. Microprocessor power supplies with all surface mount ponents can be easily built. The internal high speed transconductance amplifier specifies good dynamic performance. The internal master clock frequency of up to 8 MHz is set by an external reference resistor. An external clock of 10 MHz...