A rectifier is an electronic circuit which can convert an AC voltage into DC voltage. In half-wave rectifier, only a positive cycle is rectified. A circuit, which can rectify both positive and negative cycle is known as a full-wave rectifier.
R-2R ladder DAC is the most widely used circuit for converting the digital signal into the analog signal. For implementing R-2R DAC we require only two different values of resistors, one is R and other is 2R.