thanks to every one over here,
Raghunathan thanks man i got your points, i,m trying to check my sensors is it working or not using the same circuit that i posted befor. its working well.

i have used IN0, as the address bits are low. the output it fine.

but i got lost with sensors, currently i,m using photodiode and the output is variable dc line, when there is any reflecting surface so the output goes low beyond 0.15 v, and when there is no any surface the O/P is 4.5v

but when i applied this dc line as analog input though IN0, the result is dc variable dc line.

so any one can tell me, is the output variable dc line from ADC is an digital signals.
and does the microcontroller can accept that dc variable??

REgards
ALbarkani