SC198_07 Datasheet, PDF (1/16 Pages) Semtech Corporation – Dual DC-DC Buck Converter with High Current Capability

POWER MANAGEMENT
Description
The SC198 is a high-efficiency, dual synchronous buck
converter designed for use in low power applications. Each
converter is capable of supplying up to 600mA of average
current at one of eight programmable output voltages
commonly used as microprocessor supply voltages.
The SC198 uses a single control logic block for the two
converters, but their controls can be set independently.
The SC198 employs a flexible clocking scheme that
allows the user to use the fixed internal 1MHz oscillator or
synchronize the clock to an external source. The device
also has an optional power-save mode that optimizes
efficiency for light loads.
SC198
Dual DC-DC Buck Converter
with High Current Capability
Features
Dual buck converters with independent control
High efficiency - over 90% peak
8 programmable output voltages
Input voltage range between 2.7V to 5.5V
Fixed-frequency operation - 1MHz
Optional SYNC clock input
Optional power-save under light-load conditions
Shutdown current <1μA
Soft-start to limit in-rush current
4mm x 4mm MLPQ package
The SC198 provides output voltage flexibility while
conserving board space by using control pins to select
the output voltage instead of external resistor voltage
divider circuits. This eliminates at least four parts from
the traditional dual buck converter bill of materials.
Applications
Mobile phones
Cordless phones
MP3 players
Digital cameras
PDAs
Single li-ion cell or (3) NiMH/NiCd cell devices
Digital multimedia broadcast (DMB) devices
Portable gaming systems
Typical Application Circuit
1 _VINA ^SC198
4.7μH
2
18 _VINR
LXA
4
15 _VINB
VOUTA
3
20
GNDA
10μF
ENA
5 _CTLA0
6 _CTLA1
7 _CTLA2
4.7μH
14
LXB
16
ENB
12
VOUTB
11 _CTLB0
GNDB ¹³
10 _CTLB1
9 _CTLB2
GNDR ⁸
17 _SYNC
VOUTA
10μF
VOUTB
10μF
March 28, 2007
www.semtech.com
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