LTC4020 datasheet(13/42 Pages) LINER

13 / 42 page

LTC4020

4020fd

For more information www.linear.com/LTC4020

BG2 (Pin 33): VOUT side (step-up) primary switch FET

gate driver output.

INTVCC (Pin 34): Boosted Driver Refresh Supply. This

supply is regulated to 5V and is current limited to 150mA.

Connect a 2.2µF ceramic capacitor from this pin to PGND.

Boosted supply refresh diode anodes are connected to

this pin. Using this pin to power external 5V circuitry is

not recommended.

PGND(Pin35):Switchhighcurrentreturnpathforstep-up

primary and step-down synchronous switches.

PVIN (Pin 36): High Current Input Supply Pin. Connect

10µFdecouplingcapacitorfromthispintoPGND.ThePVIN

pin provides input supply current for the INTVCC internal

5V linear regulator.

BG1 (Pin 37): VIN side (step-down) synchronous switch

FET gate driver output.

SW1 (Pin 38): Switched node for step-down switches.

Connect the switched inductor to this pin. Connect the

primary switch FET source and synchronous switch FET

drain to this pin.

SGND(Pins3,29,ExposedPad39):SignalGroundRefer-

ence. Connect to the output decoupling capacitor negative

terminal and battery negative terminal. The exposed pad

(39)mustbesolderedtoPCBground(SGND)forelectrical

connection and rated thermal performance.

pin FuncTions

LTC4020 Datasheet(PDF) 13 Page - Linear Technology