EUP2571
Typical Application Circuit (continued)
Figure 2.
5V to 9V/300mA Step-Up Application
Pin Configurations
Package Type
Pin Configurations
Package Type
Pin Configurations
SOT23-5
SOT23-6
Pin Description
PIN
LX
GND
FB
EN
IN
OUT
SOT23-5
1
2
3
4
5
-
SOT23-6
1
2
3
4
6
5
DESCRIPTION
Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to
reduce EMI.
Common Ground
Feedback Pin. Reference voltage is 0.25V. Connect cathode of lowest LED
and resistor here. Calculate resistor value according to the formula:
R
FB
=0.25/I
LED
Chip Enable Pin. Connect to 1.4V or higher to enable device, 0.4V or less to
disable device.
Input Supply Voltage
Overvoltage Sense. When V
OUT
is greater than 27V, the internal N-channel
MOSFET turns off until V
OUT
drops below 25V, then the IC reenters start.
Connect a 1uF capacitor from OUT to GND.
DS2571 Ver1.1 May. 2007
2
EUTECH [ EUTECH MICROELECTRONICS INC ]
