Mp1583 (U174); General Description; Features; Pinning - Sharp LC-22LE240E Service Manual

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15. MP1583 (U174)

15.1. General Description

The MP1583 is a step-down regulator with a built-in internal Power MOSFET. It achieves
3A of continuous output current over a wide input supply range with excellent load and
line regulation. Current mode operation provides fast transient response and eases loop
stabilization. Fault condition protection includes cycle-by-cycle current limiting and thermal
shutdown. An adjustable soft-start reduces the stress on the input source at start-up. The
MP1583 requires a minimum number of external components, providing a compact
solution.

15.2. Features

 3A Output Current
 Programmable Soft-Start
 100mΩ Internal Power MOSFET Switch
 Stable with Low ESR Output Ceramic Capacitors
 Up to 95% Efficiency
 20μA Shutdown Mode
 Fixed 385KHz Frequency
 Thermal Shutdown
 Cycle-by-Cycle Over Current Protection
 Wide 4.75V to 23V Operating Input Range
 Output Adjustable from 1.22V to 21V
 Under-Voltage Lockout

15.3. Pinning

Pin Pin
No. Name
1 BOOT
2
IN
3 SW
4
GND
5 FB
6 COMP
7 EN
8 SS
16. FDC642
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 0.1μF capacitor sets the soft-start period to
13.5ms.
Description
High-Side Gate Drive Bootstrap Input. BS supplies the drive for the
high-side N-Channel MOSFET switch.
Power Input. Drive IN with a 4.75V to 23V power source.
Power Switching Out is the switching node that supplies power to the
output
Ground.
Feedback Input. FB senses the output voltage and regulates it. Drive
FB with a resistive voltage divider from the output voltage. FB
threshold is 1.222V.
Compensation Node is used to compensate the regulation control
loop.
Enable/UVLO. A voltage greater than 2.71V enables operation. For
complete low current shutdown the EN pin voltage needs to be at less
than 900mV. When the voltage on EN exceeds 1.2V, the internal
regulator will be enabled and the soft-start capacitor will begin to
charge. The MP1583 will start switching after the EN pin voltage
reaches 2.71V.
Soft-Start Control Input. SS controls the soft-start period.
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LC-22LE240