Sharp LC-32SV502B Service Manual page 51

2.2 U411(AT1529F11U)
General Description
The AT1529 high-efficiency, DC/DC buck converter delivers up to 3.2A of output current. The device operates from an input voltage of 2.5V to 6V and
provides an output voltage from 0.8V to VIN, making the AT1529 ideal for on-board post-regulation applications.
The AT1529 operate at a fixed frequency of 1MHz with an efficiency of up to 94%. The high operating frequency minimizes the size of external
components. Internal soft-start control circuitry reduces inrush current. Short-circuit and thermal-overload protections improve design reliability.
The AT1529 are available in a space-saving SOP-8 and TDFN3X3-8 package.
Features
Ceramic Input and Output Capacitors
Efficiency Up to 94%
Operate from 2.5V to 6V supply
Adjustable Output from 0.8V to VIN
Internal Soft-Start
Short-Circuit and Thermal-Overload Protection
Input Over Voltage Protection
RoHS Compliant
Applications
ASIC/DSP/µP/FPGA Core and I/O Voltages
Set-Top Boxes
Cellular Base Stations
Networking and Telecommunications
2.3 U705(RT8074GSP)
General Description
The RT8074 is a high efficiency synchronous, step-down DC/DC converter. Its input voltage range is from 2.7V to 5.5V and provides an adjustable
regulated output voltage from 0.8V to 5V while delivering up to 4A of output current.
The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The default
switching frequency is set at 2MHz, if the RT pin is left open. It can also be varied from 200kHz to 2MHz by adding an external resistor. Current mode
operation with external compensation allows the transient response to be optimized over a wide range of loads and output capacitors.
The RT8074 operates in forced continuous PWM Mode, which minimizes ripple voltage and reduces the noise and RF interference.
Features
High Efficiency : Up to 95%
Adjustable Frequency : 200kHz to 2MHz
No Schottky Diode Required
0.8V Reference Allows Low Output Voltage
Forced Continuous Mode Operation
Low Dropout Operation : 100% Duty Cycle
Enable Function
Internal Soft-Start
RoHS Compliant and Halogen Free
Applications
LCD TV and Monitor
Notebook Computers
Distributed Power Systems
IP Phones
Digital Cameras
LC-32SV502B/LC-42SV502B/LC-42SV602B/LC-46SV602B/LC-46SV502L
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