Fast and Efficient Encoder with concurrent Bubble error correction for Flash ADC

Encoder used in Flash ADC converts Thermometer code to Binary code. It is the bottleneck in terms of speed in an ADC. The proposed encoder provides high speed with concurrent bubble error correction. It consists of two encoding blocks. First is a 1 - out of - N coder circuit and second is encoder block consisting of NAND and NOR gates. It can be used in Flash ADCs for very high speed applications. There are many encoders available like ROM encoder, Wallace tree encoder, Multiplexer based decoder, Priority encoder but in terms of performance and speed Fat tree encoder is better. The proposed encoder is the modified Fat tree encoder. The encoder doesn't require any clock like in case of ROM and has fewer components as compared to other encoders. The 1 - out of - N coder circuit selects one out of the N number of inputs and the other part of the encoder block converts the outputs to binary code by using combinational circuits. Keywords-Fat tree encoder; Flash ADC; Bubble Error; ROM encoder; Priority encoder.