i m using ir2110 for my dc motor driver.whenever the input to lin goes floating the output of ir2110 remains high. please help..

 

According to their datasheet the 2110 has a pull-down resistor at the LIN input built-in. Anyway I would not leave it open when unused (floating). Use an external pull-down resistor, whatever value reasonably low but not so low to be a burden for your signal source. For example 10k.

 

i tried it. but when the power from the microcontroller(for pwm) goes low the output at lo is still high.also i have inserted a pull down(33k ohm) at lo ,but the problem remains. i have shown the changes in pdf in following attachment

 

Ok then try to connect the input LIN directly to Ground. What happens at the output?

 

Depending on how fast your switching your PWM the 1k gate resistor is way too big. A gate resistor should be in the 4.7ohm to 50ohm range. If your PWM is high the gate never has time to shut off using the high ohm resistor.