LC-19A1E (serv.man5). Major IC Informations - Sharp TV Service Manual (repair manual). Page 27

LC-19A1E-BK/WH

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1

BST

I

Bootstrap.
This capacitor is needed to drive the power switch's gate above the supply voltage.
It is connected between SW and BS pins to from a floating supply across the power switch driver.

2

GND

-

Ground.
This pin is the voltage reference for the regulated output voltage.
For this reason care must be taken in its layout.
This node should be placed outside of the D1 to C1 ground path to prevent switching current spikes from 
inducing voltage noise into the part.

3

FB

I

Feedback.
An external resistor divider from the output to GND, tapped to the FB pin sets the output voltage.
To prevent current limit run away during a short circuit fault condition the frequency feedback comparator 
lowers the oscillator frequency when the FB voltage is below 250mV.

4

EN

I

On/Off Control input.
Pull above 1.2V to turn the device on.

5

IN

I

Supply voltage.
The MP2259 operates from a +4.5V to +16V unregulated input.
C1 is needed to prevent large voltage spikes from appearing at the input.

6

SW

O

Switch output.