Flash Analog to Digital Converter

Flash analog-to-digital converters, also known as parallel ADCs, are the fastest way to convert an analog signal to a digital signal. Flash ADCs are ideal for applications requiring very large bandwidth, but they consume more power and much bigger in size than other ADC architectures. A Flash converter requires a huge number of comparators compared to other ADCs, especially as the resolution increases. A Flash converter requires 2n-1 comparators for an n-bit conversion.


  • Circuit shown is a 3 bit flash converter
  • Reference ladder consists of 2n (23 = 8) equal size resistors
  • Input voltage is compared to 2n-1 reference voltages using 2n-1 comparators. The reference voltages can be calculated using KVL.
  • A Priority Encoder is used to transform the comparator outputs to the correct digital binary output.
  • Change the input voltage and observe the comparators and the priority encoder digital outputs.

With advertising revenues falling despite increasing numbers of learners, we need your help to maintain and improve this site, which takes time, money and hard work. Thanks to the generosity of our learners who gave earlier, you are able to use this site at no charge.

If you have benefited from this site and are able, please give via Paypal. It will allow us to continue into the future. It only takes a minute. Thanks!

US$ 2 US$ 5 US$ 10