2022-11-01 10:19 Tags: # Flash ADC Conceptually simple. ## Circuit Reference voltage is divided down to $2^N$ voltages in a resistor string. These then input to comparators along with the input voltage. The output is a [thermometer encoded](thermometer%20encoding.md) version of the input voltage. Thus you will need a thermometer to binary decoder in digital logic.  ## Avoiding Systematic Offset Need the transition points to occur at half an LSB  To do this, make the bottom resistor 1/2 the other values and the top 3/2.  ## Disadvantages - Very complex and large due to number of comparators. - Limited to 3-7 bits (127 comparators is as many as you want) ## Advantages - Very fast - output code is available in a single clock cycle (no algorithm involved) - Could run as a combinational circuit [^1] --- # References [^1]: [vr-4602-wk07-sc05-adcflash](../../Spaces/University/ELEC4602%20–%20Microelectronics%20Design%20and%20Technology/Lectures/W7/vr-4602-wk07-sc05-adcflash.mp4)