Sharp LC-40SH340E, Руководство по обслуживанию

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LC-40SH340E
LC-40SH340K
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
as low as 0.8V. It can also operate at 100% duty cycle for low dropout applications. With pea
k 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.
18.2. Features
x
2.7-6V Input Operation Range
x
Output Adjustable from 0.8V to VIN
x
†;&‡$ ˆ‡rrent.
x
Up to 95% Efficiency
x
100% Duty Cycle for Low Dropout
x
Applications
x
1.2MHz Fixed Switching Frequency
x
Stable with Low ESR Output Ceramic
x
Capacitors
x
Thermal Shutdown
x
Cycle-by-Cycle Over Current Protection
x
Short Circuit Protection
x
Available in 6-pin 3x3mm QFN
18.3. Pinning
Pin
#
Name Description
1 FB Feedbac k input. An external resistor divider from the output
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.
17.
17.1
17.2
17.3