3

Date: 6/20/06 Rev T

SP7685, 1.2A Buck/BoostCharge Pump LED Driver

© 2006 Sipex Corporation

PIN DESCRIPTION

PIN

NUMBER

PIN NAME

DESCRIPTION

Input Voltage for the charge pump. Decouple with

4.7µF ceramic capacitor close to the pins of the IC.

2C1

Positive input for the external flying capacitor. Connect

a ceramic 1µF capacitor close to the pins of the IC.

3C2

Negative input for the external flying capacitor. Connect

a ceramic 1µF capacitor close to the pins of the IC.

4

FLASH

Logic input to toggle operation between FLASH and

TORCH mode. In TORCH mode FB is regulated to the

internal 50mV reference. In FLASH mode FB reference

voltage can be adjusted by changing the resistor from

resistor (R

SENSE

) based on desired current in TORCH

mode. This pin does not have an internal pull-up/pull-

down; do not leave this pin floating.

5EN

operation, connect to ground for shutdown. This pin

does not have an internal pull-up/pull-down; do not

leave this pin floating.

Connect a resistor from this pin to ground. When in

FLASH mode (FLASH = High) this resistor sets the

7FB

Feedback input for the current control loop. Connect

directly to the current sense resistor.

Internal ground pin. Control circuitry returns current to

this pin.

Power ground pin.

Flying capacitor current returns

through this pin.

10

Charge Pump Output Voltage.

Decouple with an

external capacitor.

At least 1µF is recommended.

Higher capacitor values reduce output ripple