# LED Driver LM3410X not functioning

I am testing below LED Driver Circuitry on breadboard using LM3410X.

Input Specs:

Vin & DMM = 5V,

L = 20 uH

R=2 Ohm

Only thing is I have'nt connected LED ( I am testing with 10k resistor as dummy load) But somehow I am getting 4.86 V at o/p ( across 10K load resistor )

Can anybody help me to figure out. Do I need to connect LED string?

So you have set a current of 95mA using R1 = 2$\Omega$ (190mV typical reference) and are thusexpecting a voltage of 950V (95mA * 10K) at the output.. this will can damage the chip.
• A reasonable dummy load would be an 8.2V 1W Zener diode. This supply is a constant current type so I took the current you picked (190mV/2$\Omega$ = 95mA) and multiplied it by the 10K to get the output voltage (not counting the 190mV across the resistor). The 190mV VFB reference voltage is straight from the datasheet. – Spehro Pefhany Jan 4 '16 at 16:47