hi ... i'm looking for a 4 bit adc ic that should not have a strobe or clock pin.if u know about such ics or cites which holds information , plese tell me

 

I don't know if such a device exists.
The ADC process takes a finite time so you need the strobe to tell the sample/hold circuit in the ADC when to sample the input and hold that value till the conversion is done.
The conversion from analogue to digital needs to be controlled by some sort of clock so either the chip has to supplied with an external clock or it must generate its own internal clock.

 

now i'm trying to design a 4 bit adc using op amps and resistors that can perform instantaneous convertion.
i like that quote.........

 

Why not use the 4 lowest bits on an 8-bit A-to-D chip? You just need to set the reference to give an appropriate span for the 1111 condition.

 

You might look at an LN3914. There are more comparators than you need, but the output is immediate.