I am using following: Identical resistance of 1k ohms. For 3 bit flash adc we have (2^3)-1=7; which means we have to use 7 opamps, and 8 resistance. Opamp LM324 (V+ is applied directly form 9V battery and V- form the negative terminal of battery), Priority encoder: 74LS148 (8 line to 3 line) Analog signal form 9 volt battery which is being varied by using 5k potentiometer form 0 to 6 volt, Reference voltage is 6V.
Issue which i am having is that when analog signal is below reference voltage none of Led is on and when it exceed reference voltage all led goes in on state. Need help with this issue.