Sharp LC-22DV510K (serv.man2) Service Manual ▷ View online
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LC-22DV510
LC-24DV510
16.4.
Pinning
17. LM1117(U175, U180, U181)
17.1.
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
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 band-gap
reference to as-sure output voltage accuracy to within ±1%. The LM1117 series is available in SOT- 223,
TO-220, and TO-252 D-PAK packages. A minimum of 10μF tantalum capacitor is required at the output to
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.
17.2.
Features
Available in 1.8V, 2.5V, 2.85V, 3.3V, 5V, and Adjustable Versions
Space Saving SOT-223 Package
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
17.3.
Applications
2.85V Model for SCSI-2 Active Termination
Post Regulator for Switching DC/DC Converter
High Efficiency Linear Regulators 15
32” TFT TV Service Manual 10/01/2005
Battery Charger
Battery Powered Instrumentation
17.4.
Absolute Maximum Ratings
17.5.
Pinning
16.5
16.
16.4
16.3
16.2
16.1
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LC-22DV510
LC-24DV510
18. MP2012 (U176)
18.1.
General Description
The MP2012 is a fully integrated, internally compensated 1.2MHz fixed frequency PWM step-down
converter. It is ideal for powering portable equipment that runs from a single cell Lithium-Ion (Li+) Battery,
with an input range from 2.7V to 6V. The MP2012 can provide up to 1.5A of load current with output voltage
with an input range from 2.7V to 6V. The MP2012 can provide up to 1.5A of load current with output voltage
as low as 0.8V. It can also operate at 100% duty cycle for low dropout applications. With peak current mode
control and internal compensation, the MP2012 is stable with ceramic capacitors and small inductors. Fault
condition protection includes cycle-by-cycle current limiting and thermal shutdown.
condition protection includes cycle-by-cycle current limiting and thermal shutdown.
18.2.
Features
2.7-6V Input Operation Range
Output Adjustable from 0.8V to VIN
1μA Max Shutdown Current.
Up to 95% Efficiency
100% Duty Cycle for Low Dropout
Applications
1.2MHz Fixed Switching Frequency
Stable with Low ESR Output Ceramic
Capacitors
Thermal Shutdown
Cycle-by-Cycle Over Current Protection
Short Circuit Protection
Available in 6-pin 3x3mm QFN
18.3.
Pinning
Pin
#
Name
Description
1
FB
Feedback input. An external resistor divider from the output
to GND, tapped to the FB pin sets the output voltage.
to GND, tapped to the FB pin sets the output voltage.
2
GND, Exposed
Pad
Ground pin. Connect exposed pad to ground plane for
proper thermal performance.
3
SW
Switch node to the inductor.
4
PVIN
Input supply pin for power FET.
5
VIN
Input Supply pin for controller. Put small decoupling
ceramic near this pin.
6
EN
Enable input, “High” enables MP2012. EN is pulled to GND
with 1Meg internal resistor.
with 1Meg internal resistor.
17.
17.3
17.2
17.1
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LC-24DV510
19. RTA8283A (U23, U173)
19.1.
General Description
The RT8283A is a high-efficiency, monolithic synchronous step-down DC/DC converter that can deliver up
to 3A output current from a 4.5V to 23V input supply. The RT8283A's current mode architecture and
external compensation allow the transient response to be optimized over a wide range of loads and output
external compensation allow the transient response to be optimized over a wide range of loads and output
capacitors. Cycle-by-cycle current limit provides protection against shorted outputs and soft-start eliminates
input current surge during start-up. The RT8283A also provides output under voltage protection and thermal
shutdown protection. The low current (<3μA) shutdown mode provides output disconnect, enabling easy
shutdown protection. The low current (<3μA) shutdown mode provides output disconnect, enabling easy
power management in battery powered systems. The RT8283A is available in a SOP-8 package.
19.2.
Features
±1.5% High Accuracy Feedback Voltage
Integrated N-MOSFET Switches
Current Mode Control
Fixed Frequency Operation : 340kHz
Output Adjustable from 0.8V to 20V
Up to 95% Efficiency
Thermal Shutdown Protection
18.
18.2
18.1
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LC-22DV510
LC-24DV510
19.3.
Pinning
Pin No.
Pin
Name
Description
1
BOOT
Bootstrap for high-side gate driver. Connect a 0.1
μF or
greater ceramic capacitor from BOOT to SW pins.
2
VIN
Input Supply 4.5V to 23V. Must bypass with a suitably
large ceramic capacitor.
large ceramic capacitor.
3
SW
Phase Node--Connect to external L-C filter..
4, 9 (Exposed
Pad)
GND
Ground.
5
FB
Feedback Input pin is connected to the converter output.
It is used to set the output of the converter to regulate to
It is used to set the output of the converter to regulate to
the desired value via an internal res divider. For an
adjustable output, an external res divider is connected to
this pin.
6
COMP
Compensation Node. COMP is used to compensate the
regulation Control loop. Connect a series RC network
regulation Control loop. Connect a series RC network
from COMP to GND. In some cases, an additional
capacitor from COMP to GND is required.
7
EN
Enable Input Pin. Logic high enables the converter; a
logic low forces the RT8253A into shutdown mode.
Attach this pin to VIN with a 100kΩ pull up resistor for
automatic startup.
8
SS
Soft-Start Control Input. SS controls the soft-start period.
Connect a capacitor from SS to GND to set the soft-start
period. A 0.1
Connect a capacitor from SS to GND to set the soft-start
period. A 0.1
μF capacitor sets the soft-start period to
13.5ms.
18.3
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