POWER MANAGEMENT
1
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SC1175
Low Power Dual Synchronous DC/DC
Controller With Current Sharing Circuitry
Description
Features
Applications
Revision: September 22, 2004
The SC1175 is a versatile 2 phase, synchronous, volt-
age mode PWM controller that may be used in two dis-
tinct ways. First, the SC1175 is ideal for applications
where point of use output power exceeds any single in-
put power budget. Alternatively, the SC1175 can be used
as a dual switcher. The SC1175 features a temperature
compensated voltage reference, over current protection
with 50% fold-back and internal level-shifted, high-side
drive circuitry.
In current sharing configuration, the SC1175 can pro-
duce a single output voltage from two separate voltage
sources (which can be different voltage levels) while
maintaining current sharing between the channels. Cur-
rent sharing is programmable to allow loading each input
supply as required by the application.
In dual switcher configuration, two feedback paths are
provided for independent control of the separate out-
puts. The device will provide a regulated output from
flexibly configured inputs (3.3V, 5V, 12V), provided 5V is
present for V
CC
. The two switchers are 180° out of phase
to minimize input and output ripple.
300kHz fixed frequency operation
Soft Start and Enable function
Power Good output provided
Over current protection with 50% fold-back
Phase-shifted switchers minimize ripple
High efficiency operation, >90%
Programmable output(s) as low as 1.25V
Industrial temperature range
20 pin SOIC or TSSOP package
Two Phase, Current Sharing Controller
Flexible, same or separate V
IN
Programmable current sharing
Combined current limit with fold-back
2 phases operating opposed for ripple reduction
Thermal distribution via multi-phase output
Two Independent PWM Controllers
Flexible, same or separate V
IN
Independent control for each channel
Independent and separate current limit
2 phases operating opposed for ripple reduction (if
same V
IN
used)
Graphics cards
DDR Memory
Peripheral add-in card
SSTL Termination
Dual-Phase power supply
Power supplies requiring two outputs
