LM3914 Battery Monitor problem..

[cheewooi]

Hey guys, need some help from pro. Juz build my 7.2 Volt Lithium Ion Battery monitor using LM3914 Led Driver. I build the circuit based on the datasheet typical application circuit. Pin 5 is the input voltage sensing. Before I connect the Pin 5, all the LED lit. Anyone knows the problem?

BTW, anyone have 7.2V battery monitor examples?

Thank you

 

[audioguru]

Hi Cheewooi,
The LM3914's input pin 5 has a tiny input bias current coming out of it to ground, so if you let the pin 5 float without having a resistor to ground, it will pull pin 5 high and read full scale.