SC2688 Datasheet, PDF (1/12 Pages) Semtech Corporation – Programmable Synchronous DC/DC Converter, 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 out-
put 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
10
x4
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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