Sharp LC-50LE771E Service Manual ▷ View online
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MP1484
a) General Description
The MP1484 is a monolithic synchronous buck regulator. The device integrates top and bottom 85mΩ
MOSFETS that provide 3A of continuous load current over a wide operating input voltage of 4.75V to
18V. Current mode control provides fast transient response and cycle-by-cycle current limit.
An adjustable soft-start prevents inrush current at turn-on and in shutdown mode, the supply current
drops below 1μA. The MP1484 is PIN compatible to the MP1482 2A/18V/Synchronous Step-Down
Converter.
b) Features
• 3A Continuous Output Current
• Wide 4.75V to 18V Operating Input Range
• Integrated 85mΩ Power MOSFET Switches
• Output Adjustable from 0.925V to 20V
• Up to 95% Efficiency
• Programmable Soft-Start
• Stable with Low ESR Ceramic Output Capacitors
• Fixed 340KHz Frequency
• Cycle-by-Cycle Over Current Protection
• Input Under Voltage Lockout
• Thermally Enhanced 8-Pin SOIC Package
APPLICATIONS
• FPGA, ASIC, DSP Power Supplies
• LCD TV
• Green Electronics/Appliances
• Notebook Computers
Figure: General description
Figure: General description
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Table: Pin functions.
APL5910
a) General Description
The APL5910 is a 1A ultra low dropout linear regulator. The IC needs two supply voltages, one is a
control voltage (VCNTL) for the control circuitry, the other is a main supply voltage (VIN) for power
conversion, to reduce power dissipation and provide extremely low dropout voltage. The APL5910
integrates many functions. A Power-On-Reset (POR) circuit monitors both supply voltages on VCNTL
and VIN pins to prevent erroneous operations. The functions of thermal shutdown and current-limit protect
the device against thermal and current over-loads. A POK indicates that the output voltage status with a
delay time set internally. It can control other converter for power sequence. The APL5910 can be enabled
by other power systems. Pulling and holding the EN voltage below 0.4V shuts off the output.
The APL5910 is available in a SOP-8P package which features small size as SOP-8 and an Exposed
Pad to reduce the junction-to-case resistance to extend power range of applications.
b) Features
Ultra Low Dropout
-0.12V (Typical) at 1AOutput Current
0.8V Reference Voltage
High Output Accuracy
-±1.5%over Line, Load, and Temperature Range
Fast Transient Response
Adjustable Output Voltage
Power-On-Reset Monitoring on Both VCNTL and VIN Pins
Internal Soft-Start
Current-Limit and ShortCurrent-Limit Protections
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Thermal Shutdown with Hysteresis
Open-Drain VOUT Voltage Indicator (POK)
Low Shutdown Quiescent Current (< 30mA )
Shutdown/Enable Control Function
Simple SOP-8P Package with Exposed Pad
Lead Free and Green Devices Available (RoHS Compliant)
APPLICATIONS
Motherboards, VGA Cards
Notebook PCs
Add-in Cards
Figure: Pin configuration.
Table: Recommended operating conditions.
Table: Pin description.
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Thermal Shutdown with Hysteresis
Open-Drain VOUT Voltage Indicator (POK)
Low Shutdown Quiescent Current (< 30mA )
Shutdown/Enable Control Function
Simple SOP-8P Package with Exposed Pad
Lead Free and Green Devices Available (RoHS Compliant)
APPLICATIONS
Motherboards, VGA Cards
Notebook PCs
Add-in Cards
Figure: Pin configuration.
Table: Recommended operating conditions.
Table: Pin description.
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LM1117
a) General Description
The LM1117 is a series of low dropout voltage regulators with a dropout of 1.2V at
800mA of load current. It has the same pin-out as National Semiconductor’s industry standard
LM317.
The LM1117 is available in an adjustable version, which can set the output voltage from
1.25V to 13.8V with only two external resistors. In addition, it is also available in five fixed
voltages, 1.8V, 2.5V, 2.85V, 3.3V, and 5V.
The LM1117 offers current limiting and thermal shutdown. Its circuit includes a zener
trimmed bandgap reference to assure output voltage accuracy to within ±1%.
The LM1117 series is available in LLP, TO-263, SOT-223, TO-220, and TO-252 D-PAK
packages. A minimum of 10µF tantalum capacitor is required at the output to improve the
transient response and stability.
b) Features
Available in 1.8V, 2.5V, 2.85V, 3.3V, 5V, and Adjustable Versions
Space Saving SOT-223 and LLP Packages
Current Limiting and Thermal Protection
Output Current 800mA
Line Regulation 0.2% (Max)
Load Regulation 0.4% (Max)
Temperature Range:
- LM1117 0˚C to 125˚C
- LM1117I −40˚C to 125˚C
Applications
- 2.85V Model for SCSI-2 Active Termination
- Post Regulator for Switching DC/DC Converter
- High Efficiency Linear Regulators
- Battery Charger
- Battery Powered Instrumentation
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