SC1157

PROGRAMMABLE SYNCHRONOUS DC/DC CONTROLLER FOR ADVANCED PROCESSORS Preliminary - August 7, 2000 SC1157 TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com DESCRIPTION The SC1157 is a low-cost, full featured, synchronous voltage-mode controller designed for use in single ended power supply applications where efficiency is of primary concern. Synchronous operation allows for the elimination of heat sinks in many applications. The SC1157 is ideal for implementing DC/DC converters needed to power advanced microprocessors such as Pentium® ll (Klamath), in both single and multiple processor configurations. Internal level-shift, high-side drive circuitry, and preset shoot-thru control, allows for use of inexpensive n-channel power switches. SC1157 features include an integrated 4-bit VID DAC, temperature compensated voltage reference, triangle wave oscillator, current limit comparator, frequency shift over-current protection, and an internally compensated error amplifier. The SC1157 operates at a fixed 140KHz, providing an optimum compromise between efficiency, external component size, and cost. FEATURES = Low cost / full featured = Synchronous operation = 4 Bit VID DAC programmable output = Designed to meet Intel VRM8.2 (Pentium® II) = 1.5% Reference APPLICATIONS = Pentium® II Core Supply = Multiple Microprocessor Supplies = Voltage Regulator Modules (VRM) = Programmable Power Supplies = High Efficiency DC/DC Conversion ORDERING INFORMATION DEVICE (1) (1% tol...