LTC3370 datasheet(8/20 Pages) AD

8 / 20 page

LTC3302

Rev. 0

For more information www.analog.com

PIN FUNCTIONS

EN (Pin 1): The EN pin has a precision enable threshold

with hysteresis. An external resistor divider, from VIN or

from another supply, can be used to program the thresh-

old below which the LTC3302 shuts down. If the precision

threshold is not required, tie EN directly to VIN. When the

EN pin is low the LTC3302 enters a low current shutdown

mode where all internal circuitry is disabled. Do not float

this pin.

VIN (Pins 2, 3): The VIN pins supply current to the top-

side power switch. Connect both VIN pins together with

a short, wide trace and bypass to PGND with a low-ESR

capacitor located as close to the pins as possible.

SW (Pins 4, 5): The SW pins are the switching outputs of

the internal power switches. Connect these pins together

and to the inductor with a short, wide trace.

PGND (Pins 6, 7): The PGND pins are the return path

of the internal bottom side power switch. Connect the

negative terminals of the input capacitors as close to the

PGND pins as possible.

MODE/SYNC (Pin 8): The MODE/SYNC pin is a mode

selection and external clock synchronization input. Float

this pin to enable pulse-skipping mode at light loads.

For higher efficiency at light loads, tie this pin to AVIN to

enable low-ripple Burst Mode operation. For faster tran-

sient response, lower noise, and full frequency opera-

tion over a wide load range, connect this pin to AGND

to enable forced continuous mode. Drive MODE/SYNC

with an external clock to synchronize the switcher to the

applied frequency. While synchronizing, the part operates

in forced continuous mode.

PGOOD (Pin 9): The PGOOD pin is the open-drain output

of an internal power good comparator. When the regulated

output voltage falls below the PGOOD threshold or rises

above the overvoltage threshold, this pin is pulled low.

When VIN is above the UVLO threshold and the part is in

shutdown, this pin is also pulled low.

FB (Pin 10): FB is the output voltage feedback pin for the

LTC3302 adjustable version. The FB pin is regulated to

500mV. Program the output voltage and close the con-

trol loop by connecting this pin to the middle node of a

resistor divider between the regulator output and AGND.

VOUT (Pin 10): VOUT is the regulated output voltage pin

for the LTC3302 fixed voltage versions. For the fixed VOUT

versions, connect this pin directly to the regulator output.

Connect a low-ESR capacitor from this node to AGND.

AGND (Pin 11): The AGND pin is the output voltage

remote ground sense. Connect the AGND pin directly to

the negative terminal of the output capacitor at the load.

The AGND pin is also the ground reference for the internal

analog circuitry. Place a 1μF ceramic bypass capacitor as

close as possible to the AVIN and AGND pins. Connect FB

return to AGND as well.

AVIN (Pin 12): The AVIN pin supplies current to the internal

analog circuitry. Decouple this pin to AGND with a 1µF

low-ESR capacitor to AGND.

LTC3370 Datasheet(PDF) 8 Page - Analog Devices

LTC3370 Datasheet(HTML) 8 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Datasheet Download

Link URL