Analysis & Comparison of Digital to Analog Converter in Different CMOS Technology

We investigated and compared DAC (Digital to Analog Converter) in various CMOS process technologies like 180 nm, 65 nm and 55 nm. DAC is used to provide the analog voltage converted from the digital input. The circuit under consideration is a simpler circuit of DAC for CUWB (Cognitive ultra-wide band) network. To achieve simpler design the resolution is limited to 4 bits only. The design is realized in standard 180 nm, 65 nm & 55 nm CMOS technology. The design comprises of deglitcher, current switches and current sources. Current switches are the output analog parts of the design. Deglitcher is used to reduce the unwanted glitches introduced in the circuit. Current sources are designed in the binary implementation which reduces the hardware area and complexity. Deglitcher circuit is made from the David - Goliath inverter and a pair of the of source followers to tackle the unwanted noise in the circuit. Current switches are introduced so as to convert the analog voltage according to the input from the deglitcher output. The results suggest that with the downscaling or advancement in process technology node, higher frequencies can be achieved. INL and DNL of the circuit is so adjusted with relation of output impedance of the circuit.