BIST scheme for DAC testing

A low-cost, built-in self-test (BIST) scheme for a digital-to-analogue converter (DAC) is presented. The basic idea is to convert the DAC output voltages corresponding to different input codes into different oscillation frequencies through a voltage controlled oscillator (VCO), and further transfer these frequencies to different digital codes using a counter. According to the input and output codes, performances of a DAC, such as offset error, gain error, differential nonlinearity (DNL), integral nonlinearity (INL), could be effectively detected by simply using digital circuits rather than complex analogue ones. In addition, the annoying DAC output noise could be naturally filtered out by this BIST method.