sp7685 Exar Corporation, sp7685 Datasheet - Page 3

• Manufacturer Part Number: sp7685
• Description: 1.2a Buck/boost Charge Pump Led Driver
• Manufacturer: Exar Corporation

Date: 6/20/06 Rev T
NUMBER
PIN
10
1
2
3
4
5
6
7
8
9
PIN NAME
V
C1
C2
FLASH
EN
R
FB
S
P
V
IN
SET
GND
GND
OUT
Input Voltage for the charge pump. Decouple with
4.7µF ceramic capacitor close to the pins of the IC.
Positive input for the external flying capacitor. Connect
a ceramic 1µF capacitor close to the pins of the IC.
Negative input for the external flying capacitor. Connect
a ceramic 1µF capacitor close to the pins of the IC.
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
R
resistor (R
mode. This pin does not have an internal pull-up/pull-
down; do not leave this pin floating.
Shutdown control input. Connect to V
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
current regulation point according to the following: V
R
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.
Charge Pump Output Voltage.
external capacitor. At least 1µF is recommended.
Higher capacitor values reduce output ripple
SP7685, 1.2A Buck/BoostCharge Pump LED Driver
SET
SET
*14uA/5 (Flash Mode)
pin to ground. Choose the external current sense
SENSE
3
) based on desired current in TORCH
DESCRIPTION
Decouple with an
PIN DESCRIPTION
IN
© 2006 Sipex Corporation
for normal
FB
=