LTC3314AACBZ-R7 datasheet(11/26 Pages) AD

11 / 26 page

LTC3314A

Rev. 0

For more information www.analog.com

PIN FUNCTIONS

EN2 (Lead E5): Active High Enable Input for Buck

Regulator 2. The EN2 pin has a precision threshold. An

external resistor divider from VIN, or from another sup-

ply, can be used to program when Buck Regulator 2 is

enabled. If the enable function is not required, tie EN2

directly to AVIN. The EN2 pin should not be floated.

PVIN2 (Leads F1, F2): Input Supply for Buck Regulator

2. Supplies gate drive circuits and inductor current when

the high side turns on. Bypass PVIN2 to PGND with a

separate low ESR capacitor close to the pins. PVIN1 and

PVIN2 should be shorted externally. Use separate capaci-

tors to PGND for PVIN1 and PVIN2 to prevent interaction

between the buck regulators. There is an internal 20Ω

resistor from PVIN2 to AVIN to help create a filtered supply

for the internal control circuits.

BST2 (Lead F4): Internal supply for high side gate drive

circuits for Buck 2. Connect a 22nF capacitor from SW2

to BST2 close to the pins.

FB2 (Lead F5): Feedback Input for Buck Regulator 2.

Program the output voltage of Buck 2 by connecting this

pin to the middle node of a resistor divider between the

output and ground. The FB2 pin is regulated to 500mV. A

phase lead capacitor connected between VOUT2 and FB2

may be used to optimize transient response. Connect

FB2 to AVIN to program the part for single output,

2-phase operation.

LTC3314AACBZ-R7 Datenblatt(PDF) 11 Page - Analog Devices