FAN5037 Datasheet, PDF (1/11 Pages) Fairchild Semiconductor – Adjustable Switching Regulator Controller

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FAN5037
Adjustable Switching Regulator Controller
Features
• High power switch-mode DC-DC controller can provide
in excess of 13A
• Output voltage adjustable from 1.2V to 3.6V
• 85% efficiency
• Cumulative accuracy < 3% over line, load, and
temperature variations
• Overvoltage and short circuit protection
• Built-in soft start
• No overshoot at turn-on
Applications
• I/O and AGP power for desktop computers
• High efficiency power for ASICs
• High efficiency power for DSPs
• Adjustable step-down power supplies
Description
The FAN5037 is a high power, switch-mode DC-DC control-
ler that provides efficient power for all low-voltage applica-
tions. This controller has a built-in Soft Start feature which
offers system protection during power-up by reducing both
inrush current and output overshoot. When combined with
the appropriate external circuitry, the FAN5037 can deliver
load currents as high as 13A at efficiencies as high as 88%.
The FAN5037 can generate output voltages from 1.2V up to
3.6V using external resistors.
The FAN5037 is designed to operate in a constant on-time
control mode under all load conditions. Its accurate low TC
reference eliminates the need for precision external compo-
nents in order to achieve the tight tolerance voltage regula-
tion required by many applications. Short circuit current
protection is provided through the use of a current sense
resistor, while overvoltage protection is provided internally.
Block Diagram
FAN5037
5V
VCCA 2
Feedback Control
+12V +5V
IFBL 4
IFBH 3
VCCP 8
CEXT
1
Oscillator
Digital Logic
7
DRV
Vout
1.20V
Reference
GNDP 6
VFB 5
REV. 1.0.3 9/26/01