ADC0808 clock

Does the ADC 0808 require an external clock thru a uC or 555 in astable mode?
Or does it have an inbuilt internal clock? If yes, what is the default frequency?

elexhobby said:

Does the ADC 0808 require an external clock thru a uC or 555 in astable mode?
Or does it have an inbuilt internal clock? If yes, what is the default frequency?

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Going from memory?, it requires an external clock, the spec for it will be listed in the datasheet.

However, if you're using a micro-controller to control it, why not just choose a micro-controller with in-built A2D?.

Yes u r right.
But I am doing this as an exercise to learn the 8051 instruction set.
I have used PIC16F877A just once b4 & it has an in-built ADC.
BTW, Do u know any inexpensive 8051 IC that has an inbuilt ADC. (Atmel 89c52 costs just Rs.60/- (approx $1.5))
I referred the data sheet, but couldn't make out much. I tried running ADC0808 in free running mode with LEDs connected to o/p & without clock, but the digital o/p seemed to be varying randomly.