ADC0808 clock

[elexhobby]

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?

 

[Nigel Goodwin]

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?

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?.

 

[elexhobby]

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.