MB3871

FUJITSU SEMICONDUCTOR DATA SHEET DS04-27219-3E ASSP For Power Supply Applications Mobile Pentium® II DC/DC Converter IC MB3871 s DESCRIPTION The FUJITSU MB3871 is a pulse width modulation (PWM) DC/DC converter IC chip that provides a selection of 1.3 V to 2.0 V output voltages for Mobile Pentium® II* CPU’s, using a 4-bit input signal information. The MB3871 utilizes synchronous rectification for high efficiency and features a soft-start/discharge control function for ease in designing power supplies in multi-supply systems, making it ideal for Mobile Pentium® II power supply systems. * : Pentium is the registered trademark of Intel Corporation. s FEATURES Highly efficient for using synchronous rectification scheme On-chip soft-start/discharge control circuit High precision output voltage: ±1.2% 4-bit, 16-step DAC: 2.0 V to 1.3 V in 50 mV steps Frequency range: 100 kHz to 500 kHz using variable resistance (on-chip frequency setting capacitance) Standby current: 0 µA TYP On-chip PWRGOOD circuit for output voltage state detection Timer-latch short-circuit protection circuit, and overvoltage protection circuit for output protection s PACKAGE 24-pin Plastic SSOP (FPT-24P-M03) MB3871 s PIN ASSIGNMENT (Top view) RT : 1 RS : 2 SGND : 3 CS : 4 –IN : 5 FB : 6 ENB : 7 OUT1 : 8 VS : 9 CB : 10 OUT2 : 11 PGND : 12 24 : VREF 23 : VCC 22 : CSCP 21 : PWRGOOD 20 : VSENSE 19 : CTL 18 : TEST 17 : VD3 16 : VD2 15 : VD1 14 : VD0 13 : VB (FPT-24P-M03) 2 MB3871 s PIN DE...