LT3757 datasheet(10/22 Pages) AD

10 / 22 page

LT3935

Rev. 0

For more information www.analog.com

PIN FUNCTIONS

SYNC/SPRD: Synchronization Pin. To override the pro-

grammed switching frequency, drive this pin with an

external clock having a frequency between 200kHz and

2MHz. Even when using the external clock, select an RT

resistor that corresponds to the desired switching fre-

quency. Tie the pin to INTVCC to enable spread spectrum

frequency modulation. This pin should be tied to GND

when not in use.

BST: Boost Pin. This pin supplies the high side power

switch driver. Connect a 100nF capacitor between this pin

and SW. An internal charge pump from INTVCC to BST will

charge the capacitor when the SW pin is low.

PWM: PWM Input Pin. With the RP pin tied to GND, tie

this pin to VREF or INTVCC pin when PWM dimming is

not required.

RP: PWM Resistor Pin. Tie this pin to GND.

VOUT: Tie this pin to the output voltage even if dimming

is not required.

GND: Ground Pins. These must be soldered to the ground

plane of the circuit board.

NC: No Connection Pins.

LT3757 Datasheet(PDF) 10 Page - Analog Devices