LP3390 Datasheet, PDF (2/8 Pages) Lowpower Semiconductor inc – 1.2MHzFixed-Frequency PWM Operation

Preliminary Datasheet
LP3390
Functional Pin Description
Pin Number
Pin Name
Pin Function
1
GND
Ground Pin
2
VIN2
Supply Input Voltage Pin. Bypass 1uF capacitor to GND to reduce the input
noise.
3
EN2
Chip Enable (Active High). Voltage sensing input to trigger the function of over
voltage protection. Note that this pin is high impedance. There should be a pull
low 100kΩ resistor connected to GND when the control signal is floating.
4
FB1
Feedback Reference Voltage Pin. Series connect a resistor between WLED and
ground as a current sense. Sense the current feedback voltage to set the
current rating. FB voltage is 200mV.
5
SW1
Switch Pin. Connect this Pin to inductor and catch diode. Minimize the track
area to reduce EMI.
6
VIN1
Supply Input Voltage Pin. Bypass 1uF capacitor to GND to reduce the input
noise.
7
OVP
OVP Pin. Overvoltage Sense. When VOUT is greater than 29V, the internal
N-channel MOSFET turns off until VOUT drops below 29V, then the IC reenters
start. Connect a 1uF capacitor from OUT to GND
8
EN1
Chip Enable (Active High). Voltage sensing input to trigger the function of over
voltage protection. Note that this pin is high impedance. There should be a pull
low 100kΩ resistor connected to GND when the control signal is floating.
9
FB2
Feedback Reference Voltage Pin. Series connect a resistor between WLED and
ground as a current sense. Sense the current feedback voltage to set the
current rating. FB voltage is 1250mV.
10
SW2
Switch Pin. Connect this Pin to inductor and catch diode. Minimize the track
area to reduce EMI.
LP3390 Version 1.0 Datasheet
NOV.-2013 www.lowpowersemi.com
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