SC2655
SC2655 is Programmable Synchronous DC/DC Hysteretic Controller manufactured by SEMTECH.
Description
The SC2655 is a synchronous-buck switch-mode controller designed for use in single ended power supply applications where efficiency is the primary concern. The controller is a hysteretic type, with a user selectable hysteresis. The SC2655 is ideal for implementing DC/DC converters needed to power advanced microprocessors such as Pentium® ll I and Athlon®, in both single and multiple processor configurations. Inhibit, under-voltage lockout and soft-start functions are included for controlled power-up. SC2655 Features include an integrated 5 bit D/A converter, temperature pensated voltage reference, current limit parator, over-current protection, and an adaptive deadtime circuit to prevent shoot-through of the power MOSFET during switching transitions. Power good signaling, logic patible shutdown, and over-voltage protection are also provided. The integrated D/A converter provides programmability of output voltage from 1.1V to 1.85V in 25m V increments. The SC2655 high side driver can be configured as either a ground-referenced or as a floating bootstrap driver. The high and low side MOSFET drivers have a peak current rating of 2 amps.
Features
Programmable hysteresis 5 bit DAC programmable output (1.1V-1.85V) On-chip power good and OVP functions Designed to meet latest Intel specifications Up to 95% efficiency VIDs pulled up to +3.3V
Applications
Server Systems and Workstations Pentium® III Core Supplies AMD Athlon® Core Supplies Multiple Microprocessor Supplies Voltage Regulator Modules
Typical Application Circuit
+5V R1
- R3
- R2 1k 2 R4 1k DROOP VID0 27 U1 SC2655 1 IOUT PWRGD 28 C6 0.1 INHIB 3 OCP VID1 26 R11 1k C7 0.1 R9 10k R10 1k PWRGD
"POWER GOOD"
"INHIBIT"
4 R5
- C1 0.1 C2 0.001
VHYST
VID2
VREFB
VID3
L1 0.5u H
R6 20k
VSENSE
VID4
23 Cin HF Cin Bulk
+
Vin +5V/12V
AGND
INHIBIT
8 C3 0.1...
