Synchronous Buck Converter
with Integrated Power Devices
POWER MANAGEMENT
Description
The SC192 is a synchronous step-down converter with
integrated power devices designed for battery operated
systems. The internal power switches reduce system
size and cost. In addition, an efficiency of 95% can be
achieved for significant line and load ranges. The SC192
is designed for single-cell Li-Ion battery applications, but
also performs well in fixed 3.3V or 5V input circuits.
The SC192 has a flexible clocking scheme. It can be
synchronized to an external oscillator, fixed to the inter-
nal oscillator, or allowed to modulate the frequency dur-
ing light loads (PSAVE) for maximum battery life, by the
method called pulse frequency modulation (PFM). Shut-
down places the switches in a high impedance state and
turns off all control circuitry to achieve a typical quies-
cent current of 0.1μA.
Line and load regulation is to +/-0.5% of the output volt-
age. The internal MOSFET switches provide >1A peak
current to provide a DC output of at least 700mA.
Grounding the ILIM pin reduces the current limit by half.
The SC192 can achieve 100% duty cycle for excellent
low dropout performance and comes in a tiny MLPD-10,
3 x 3 package having a maximum height of 1mm.
SC192
Features
2.7V to 7V Input Range
Output Adjustable from 0.75V to Vin
Fixed Frequency or PSAVE for Maximum
Efficiency Over Wide Load Current Range
700mA Guaranteed Output Current
No Schottky Diode Required
35μA Quiescent Current
100% Duty Cycle in Dropout
95% Efficiency
Fast Transient Response
Over Temperature Protection
Space-saving Micro Lead-Frame Package
MLPD-10 3x3
Applications
Cell Phones
Cordless Phones
Notebook and Subnotebook Computers
PDAs and Mobile Communicators
1 Li-Ion or 3 NiMH/NiCd Powered Devices
Typical Application Circuit
SC192
Vin = 2.7V to 7V
L1
1
VIN
LX
9
Vout = 0.75V to Vin
C1
8
EN
ADJ
5
C5
R1
C6
R2
6
ILIM
PGND
2
10
BP
SYNC/PWM
7
C3
3
GND
COMP
4
R8
C4
Revision 8, March 26, 2007
1
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