Sharp LC-19S7E-BK Service Manual page 50

LC-19S7E-BK LC-26S7E-BK LC-32S7E-BK
High Efficiency Synchronous Step-Down Converter With up to 95% Efficiency
2.5-V to 6-V Input Voltage Range
Adjustable Output Voltage Range From 0.7 V to V1
Fixed Output Voltage Options Available
Up to 300 mA Output Current
-MHz Fixed Frequency PWM Operation
Highest Efficiency Over Wide Load Current Range Due to Power Save Mode
15-μA Typical Quiescent Current
Soft Start
100% Duty Cycle Low-Dropout Operation
Dynamic Output-Voltage Positioning
Available in a 5-Pin SOT23 Package
APPLICATIONS
PDAs and Pocket PC
Cellular Phones, Smart Phones
Low Power DSP Supply
Digital Cameras
Portable Media Players
Portable Equipment
1.6. U7103 (SC4524BSETRT)
DESCRIPTION
The SC4524B is a constant frequency peak current-mode step-down switching regulator capable of producing 2A output current from an input
ranging from 3V to 16V. The switching frequency of the SC4524B is programmable up to 2MHz, allowing the use of small inductors and ceramic
capacitors for miniaturization, and high input/output conversion ratio. The SC4524B is suitable for next generation XDSL modems, high-definition
TVs and various point of load applications.
Peak current-mode PWM control employed in the SC4524B achieves fast transient response with simple loop compensation. Cycle-by-cycle
current limiting and hiccup overload protection reduces power dissipation during output overload. Soft-start function reduces input start-up current
and prevents the output from overshooting during power-up.
FEATURES
Wide input range: 3V to 16V
2A Output Current
200kHz to 2MHz Programmable Frequency
Precision 1V Feedback Voltage
Peak Current-Mode Control
Cycle-by-Cycle Current Limiting
Hiccup Overload Protection with Frequency Foldback
Soft-Start and Enable
Thermal Shutdown
Thermally Enhanced 8-pin SOIC Package
Fully RoHS and WEEE compliant
APPLICATIONS
XDSL and Cable Modems
Set Top Boxes
Point of Load Applications
CPE Equipment
DSP Power Supplies
LCD and Plasma TVs
1.7. U1801 (STMPS2171STR SOT23-5L)
DESCRIPTION
The STMPS2141, STMPS2151, STMPS2161,STMPS2171 power distribution switches are intended for applications where heavy capacitive
loads and short circuits are likely to be encountered. These devices incorporate 90 mΩ N-channel MOSFET high-side power switches for power-
distribution. These switches are controlled by a logic enable input.
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