LM3402 Reference Design - 1 InGaN or AlInGaP LED, 160 mA

Design Specifications

Inputs	Outputs #1
VinMin=9	Vout1=3.5
VinMax=9	Iout1=0.160

Design Resources

LM3402 Reference Design

Additional Resources

•	LM3402 Product Folder
•	LM3402EVAL Evaluation Board

Bill Of Materials

Part	Manufacturer	Part#	Attributes
Cb	Vishay	VJ0805Y103KXXAT	10n F
Cf	Vishay	VJ0805Y104KXXAT	100n F
Cin	TDK	C3225X7R1H225M	NumCaps=1, 2.2u F
D1	Central Semiconductor	CMHSH5-2L	0.5 V
L1	Coilcraft	MSS5131-223ML	22u H, 0.16 Ohms
Ron	Vishay	CRCW08052942F	29.4k Ohms
Rsns	Panasonic	ERJ6BQFR56V	0.56 Ohms
U1	National Semiconductor	LM3402

Design Description

This demonstration circuit is designed to drive a single LED (InGaN or AlInGaP, Vf = 2.5V to 3.5V) at a forward current of 375 mA +- 5% with a peak-to-peak ripple current of 160 mA or less. The input is a 9V alkaline battery. Switching frequency is 800 kHz +-10%.

Schematic

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