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LC-32RD2E/S/RU, LC-37RD2E/S/RU
2.4. IC1702/IC1741/IC1758 (VHiMP1415C+-1Y)
2.4.1 Block Diagram
2.4.2 Pin Connections and short description
Pin No.
Pin Name
1
BS
2
IN
3
SW
4
GND
5
FB
6
COMP
7
EN
8
SS
I/O
Boot strap. This capacitor is needed to drive the power switch's gate above the supply voltage.
I
It is connected between the SW and BS pins to from a floating supply across the power switch driver.
I
Supply Voltage. The MP1415 operates from a +4.75V to +18V unregulated input.
O
Switch. This connects the inductor to either IN through M1 or to GND through M2.
Ground. This pin is the voltage reference for the regulated output voltage.
—
For this reason care must be taken in its layout.
Feedback. An external resistor divider from the output to GND, tapped to the FB pin, sets the output voltage.
I
To prevent current limit runaway during a short circuit fault condition the frequency fold back comparator low-
ers the oscillator frequency when the FB voltage is below 400mV.
Compensation. The node is the output of the output of the transconductance error amplifier and the input to
I
the current comparator.
Enable/UVLO. A voltage greater than 2.62V enables operation. Leave EN unconnected if unused.
I
An Under Voltage Lockout (UVLO) function can be implemented by the addition of a resistor divider from Vin
to GND. For complete low current shutdown the EN pin voltage needs to be less than 700mV.
—
Soft-start. Connect SS to an external capacitor to program the soft-start. If unused, leave it open.
Pin Function
5 – 7
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