FAN5070 Datasheet, PDF (1/14 Pages) Fairchild Semiconductor – High Performance Programmable Synchronous DC-DC Controller

www.fairchildsemi.com
FAN5070
High Performance Programmable Synchronous
DC-DC Controller
Features
• Output programmable in 25mV steps from 1.05V to
1.825V using a dynamically programmable integrated
5-bit DAC
• Remote sense
• Programmable Active Droop^™ up to 200mV
• Drives N-Channel MOSFETs
• Overcurrent protection using MOSFET sensing
• Overvoltage protection including startup
• 85% efficiency typical at full load
• Integrated Power Good and Enable/Soft Start functions
• Meets Intel VRM8.5 specifications using minimum
number of external components
• 20 pin SOIC package
Applications
• Power supply for Pentium^® III Platforms
• VRM for Pentium III processor
• Programmable power supply
Block Diagram
+5V
VCCA 17
Description
The FAN5070 is a synchronous mode DC-DC controller IC
which provides a highly accurate, programmable output volt-
age for platforms such as the Intel Pentium III, and provides a
complete solution for all Intel VRM8.5 CPU applications,
and for other high-performance processors. The FAN5070
features remote voltage sensing, independently adjustable
current limit, and a proprietary wide-range Programmable
Active Droop^™ for optimal converter transient response and
VRM8.5 compliance. The FAN5070 uses a 5-bit D/A con-
verter to dynamically program the output voltage during oper-
ation from 1.05V to 1.825V in 25mV steps. The FAN5070
uses a high level of integration to deliver load currents in
excess of 28A from a 5V source with minimal external
circuitry. Synchronous-mode operation offers optimum
efficiency over the entire specified output voltage range. An
on-board precision low TC reference achieves 0.8% voltage
regulation without expensive external components. The
FAN5070 also offers integrated functions including open-
collector Power Good, Output Enable/Soft Start and current
limiting, and is available in a 20 pin SOIC package.
-
15
+
R_D
OSC
OCL
-
+
+12V
+5V
-
14
+
R_S
16
20 VCCP
1 HIDRV
5-Bit
DAC
-
-
+
+
1.24V
Reference
Digital
Control
Power
Good
2
19 LODRV
18
GNDP
13 _PWRGD
8 765 4
VID0VID2 VID4
VID1 VID3
3
GNDA
12
ENABLE/SS
Pentium is a registered trademark of Intel Corporation. Programmable Active Droop is a trademark of Fairchild Semiconductor.
VCC
REV. 1.0.1 8/7/01