SC1176/SC1176A
Dual Synchronous Voltage Mode
Controller with Current Sharing Circuitry
POWER MANAGEMENT
Description
Features
The SC1176 is a versatile 2 phase, synchronous, volt-
age mode PWM controller that may be used in two dis-
tinct ways. First, the SC1176 is ideal for applications
where point of use output power exceeds any single in-
put power budget. Alternatively, the SC1176 can be used
as a dual switcher. The SC1176 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 SC1176 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 . The two switchers are 180° out of phase
CC
to minimize input and output ripple.
The SC1176A has the phases of the Master and the Slave
inverted.
It offers a different pattern for ripple cancellation and
prevents phase fold back during current limit.
The two chips are pin compatible.
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 .9V
Industrial temperature range
SOIC-20 or TSSOP-20 pin Lead free package. This
product is fully WEEE and RoHS compliant
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 VIN
Independent control for each channel
Independent and separate current limit
2 phases operating opposed for ripple reduction (if
same VIN used)
Applications
Graphics cards
DDR Memory
Peripheral add-in card
SSTL Termination
Dual-Phase power supply
Power supplies requiring two outputs
Revision: June 29, 2006
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