鈥?Programmable output from 1.10V to 1.85V in 25mV steps
using an integrated 5-bit DAC
鈥?Two interleaved synchronous slices for maximum
performance
鈥?100nsec response time
鈥?Built-in current sharing between slices
鈥?Remote sense
鈥?Programmable Active Droop
餂?/div>
(Voltage Positioning)
鈥?Programmable frequency from 200KHz to 2MHz
鈥?Adaptive delay gate switching
鈥?Integrated high-current gate drivers
鈥?Integrated Power Good, OV, UV, Enable/Soft Start
functions
鈥?Drives N-channel MOSFETs
鈥?Operation optimized for 5V operation
鈥?High ef铿乧iency mode (E*) at light load
鈥?Overcurrent protection using MOSFET sensing
鈥?24 pin TSSOP package
Description
The FAN5091 is a synchronous multi-slice DC-DC controller
IC which provides a highly accurate, programmable output
voltage for all high-performance processors. Two interleaved
synchronous buck regulator slices with built-in current shar-
ing operate 180掳 out of phase to provide the fast transient
response needed to satisfy high current applications while
minimizing external components. The FAN5091 features
remote voltage sensing and Programmable Active Droop
餂?/div>
for 100nsec converter transient response with minimum out-
put capacitance. It has integrated high-current gate drivers,
with adaptive delay gate switching, eliminating the need for
external drive devices. The FAN5091 uses a 5-bit D/A con-
verter to program the output voltage from 1.10V to 1.85V in
25mV steps with an accuracy of 1%. The FAN5091 uses a
high level of integration to deliver load currents in excess of
50A from a 5V source with minimal external circuitry. The
FAN5091 also offers integrated functions including Power
Good, Output Enable/Soft Start, under- voltage lockout,
over-voltage protection, and adjustable current limiting with
independent current sense on each slice. It is available in a
24 pin TSSOP package.
Applications
鈥?/div>
鈥?/div>
鈥?/div>
鈥?/div>
Power supply for Pentium
餂?/div>
IV
Power supply for Athlon
餂?/div>
VRM for Pentium IV processor
Programmable step-down power supply
Block Diagram
Bypass
6
5V Reg
+12V
18
+12V
13
23
+5V
OSC
14
+
-
Digital
Control
15
+12V
17
16
VO
+12V
12
11
+5V
-
+
-
+
-
+
-
+
Digital
Control
10
+12V
8
9
5-Bit
DAC
1 2 3 4
5
24
Power
Good
19
PWRGD
21
7
22
ENABLE/SS
20
ILIM
VID0 VID2 VID4
VID1 VID3
DROOP/E* GNDA
Pentium is a registered trademark of Intel Corporation. Athlon is a registered trademark of AMD. Programmable Active Droop is a trademark of Fairchild Semiconductor.
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