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www.fairchildsemi.com
REV. 2.0.0
Features
Combines switching regulator and low dropout linear
regulator in single chip
Linear regulator on/off control
Each output voltage adjustable from 1.5V to 3.6V
Built-in soft start
Switcher can be configured for 13A loads, linear for 5A
Precision trimmed low TC voltage reference
Constant On-Time oscillator
Small footprint 16 lead SOIC package
Applications
RAMBUS or SDRAM power with ACPI support
I/O and AGP power
High efficiency power for DSPs
Programmable dual power supply for high current loads
Description
The RC5036 combines a switch-mode DC-DC converter
with a low-dropout linear regulator. In addition, it integrates
the circuitry required to switch the DC-DC converter output
between 3.5V and a user-selectable voltage from 1.5V to 3.6V
as well as an enable function to allow the linear regulator to
be turned off when not required. RC5036 has built-in soft
start feature which offers system protection during power-up
by reducing both inrush current and output overshoot.
With the appropriate external components, the DC-DC
converter can deliver load current as high as 13A and the
linear regulator can provide 5A. The DC-DC converter and
the linear regulator can be set independently using two
external resistors each to any value between 1.5V and 3.6V.
The factory trimmed internal reference achieves tight toler-
ance voltage regulation on both outputs. Independent short
circuit protection is also provided.
Block Diagram
RC5036
–
+
LINEAR
ENABLE
SWITCHER
SELECT
FEEDBACK
CONTROL
OSCILLATOR
DIGITAL
LOGIC
SWITCHING
REGULATOR
LINEAR REGULATOR
1.5V
REFERENCE
+12V
+5V
RC5036
Dual Adjustable Voltage Regulator Controller