RC5052 Datasheet, PDF (1/18 Pages) Fairchild Semiconductor – High Performance Programmable Synchronous DC-DC Controller for Low Voltage Microprocessors

www.fairchildsemi.com
RC5052
High Performance Programmable Synchronous
DC-DC Controller for Low Voltage Microprocessors
Features
• Optimized for 12V main power
• Programmable output from 1.3V to 3.5V using an
integrated 5-bit DAC
• Remote sense
• Active Droop
• 85% efficiency typical at full load
• Integrated Power Good and Enable/Soft Start functions
• Drives N-channel MOSFETs
• Overcurrent protection using MOSFET sensing
• 20 pin SOIC package
• Meets Intel Pentium II & III specifications using
minimum number of external components
• Adjustable deadtime, frequency
• Crowbar protection for overvoltage
Applications
• Power supply for Pentium^® II & III
• VRM for Pentium II & III processor
• Telecom line cards
• Routers, switches & hubs
• Programmable step-down power supply
Description
The RC5052 is a synchronous mode DC-DC controller IC,
optimized for 12V main power, which provides a highly accu-
rate, programmable output voltage for all Pentium II & III CPU
applications and other high-performance processors. The
RC5052 features remote voltage sensing, adjustable current
limit, and active droop for optimal converter transient
response. The RC5052 uses a 5-bit D/A converter to program
the output voltage from 1.3V to 3.5V. The RC5052 uses a high
level of integration to deliver load currents in excess of 16A
from a 12V source with minimal external circuitry. Synchro-
nous-mode operation offers optimum efficiency over the
entire specified output voltage range. An on-board precision
low TC reference achieves tight tolerance voltage regulation
without expensive external components, while active droop
permits exact tailoring of voltage for the most demanding load
transients. The RC5052 also offers integrated functions
including Power Good, Output Enable/Soft Start, current
limiting, adjustable frequency, adjustable deadtime and over-
voltage crowbar protection, and is available in a 20 pin SOIC
package.
Block Diagram
Rosc 1
OSC
DTA
15
+5V
VCCA ₆
-
+
-
+
+12V
4 ^RS
13
5
11 VCCP
12 HIDRV
Digital
Control
+12V
VO
-
-
+
+
10
9 ^LODRV
5-Bit
DAC
1.24V
Reference
Power
Good
8
GNDP
3
PWRGD
20 19181716
VID0 VID2 VID4
VID1 VID3
14
GNDA
2
ENABLE/SS
7
OVP
Pentium is a registered trademark of Intel Corporation
REV. 1.3.2 8/27/01