SC2688
Programmable Synchronous DC/DC Converter, Dual LDO Controller
POWER MANAGEMENT Description
Features
The SC2688 combines a synchronous voltage mode controller with two low-dropout linear regulators providing most of the circuitry necessary to implement three DC/DC converters for powering advanced microprocessors such as Pentium® III.
·Synchronous design, enables no heatsink solution 95% efficiency (switching section) Designed for embedded Pentium® III requirements 1.5V, 2.5V sh.
Dual LDO Controller
SC2688
Programmable Synchronous DC/DC Converter, Dual LDO Controller
POWER MANAGEMENT Description
Features
The SC2688 combines a synchronous voltage mode controller with two low-dropout linear regulators providing most of the circuitry necessary to implement three DC/DC converters for powering advanced microprocessors such as Pentium® III.
·Synchronous design, enables no heatsink solution 95% efficiency (switching section) Designed for embedded Pentium® III requirements 1.5V, 2.5V short circuit protected linear controllers
The SC2688 switching section features latched drive output for enhanced noise immunity, pulse by pulse current limiting and logic compatible shutdown. The SC2688 switching section operates at a fixed frequency of 140kHz, providing an optimum compromise between size, efficiency and cost in the intended application areas.
Applications
Embedded Pentium® III microprocessor supplies.
The SC2688 linear sections are low dropout regulators with short circuit protection, supplying 1.5V for GTL bus and 2.5V for non-GTL I/O.
Typical Application Circuit
12V
5V
+ 1500uF x4
10
0.1uF EN
3.3V
11 BST 4 VCC 5 LDOEN
12 EN 16 AGND 14 LDOV 15 GATE2
3 LDOS2
SC2688S
CS+ 7 CS- 6 DH 8 DL 10 FB 13 PGND 9 GATE1 1 LDOS1 2
0.1uF 2R2 2R2
330uF
+
1.5V
+ 330uF
2.5V
+ 330uF
+
47uF
0.1uF
0.1uF 1.00k
2.32k
1.9uH
5mOhm
VCC_CORE
+ 0.1uF
1500uF x6 1k
Revision: March 25, 2004
1
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SC2688
POWER MANAGEMENT Absolute Maximum Ratings
Exceeding .