Discuss how the Discrete ADC circuit operates Your discussio

Discuss how the Discrete ADC circuit operates. Your discussion should include, at the minimum: What is the function of the R1 - R8 block? When does the Latch signal change? What functions does this signal perform? Why is U5 necessary? What is the relationship between input voltage and conversion time?

Solution

What is the function of R1-R8 block? : R1 -R8 creates R-2R resistive ladder network which takes digital binary input to generate stepped single output according to the binary value fed

When does the Latch signal change? What function does this signal perform? : U1A comparator has two inputs. One is external analog signal & another is internal analog signal generated by R-2R resistive ladder network.When the ‘internal’ analog the signal rose above the ‘external’ analog input the latch signal change. It triggers to pass the current digital value of the ‘internal’ signal from one side of the D flip-flops to the output digital lines.

Why is U5 nessasary? : U5 is nessasary to output the digital values at the reference trigger.

What is the relation between input voltage & Conversation time?: Conversation time is not dependant on input voltage. It is dependant on the resolution of ADC & Clock rate.