Multiple ramp procedure with higher order noise shaping

摘要

An analog-to-digital converter operates according to the multiple ramp procedure with continuous integration of the input signal in a charge storage or charge summation circuit, whereby downward integration is performed at periodically recurrent time intervals with the aid of a comparator circuit at the output of the charge storage or charge summation circuit, a logic circuit, a clock oscillator, a switching circuit, a first reference signal and a second reference signal. Hereby the duration of the switched-on state of one of the reference signals is a measure for the input signal. The transfer function of the quantization noise Hq(z) with an n-th order (n=1,2,3, . . . ) high pass filter characteristic can be derived from a transfer function H(z) describing the specified configuration.