Delta modulator comparing delayed analog signal - uses sum of staged reference volts and second derivative of analog signals

摘要

The delta modulator compares (VS) a reference voltage with the analog input signal and uses the result to switch the reference voltage in stages. At each point in time the first of the signals being compared has a value equal to the instantaneous value of the analog signal delayed by a given amount and the second of the signals is equal to the sum (V2) of the output of the reference voltage source (VQ) and a signal proportional to the instantaneous value of the second derivative (D1, D2) of the undelayed analog signal (E). - The advantage lies in reducing tracking errors.