Delaying analogue quadrature signals in Sin/ Cos encoders

Various measurement and control systems use magnetic or optical encoders that transform linear displacement and other physical quantities to an analogue quadrature signal. In this paper, we study the problem of, how to accurately delay the analogue quadrature signals in the Sin/Cos encoders within the range of ±10° with the circuit that is potentially integrable on a single chip. Such precision is needed for the efficient phase shift compensation. The typical analogue delay circuit comprises a summing amplifier and a digitally controlled variable resistor that is used to set a delay. We propose a new circuit based on the voltage divider with better linearity and a completely symmetrical range. The design procedure for the delay circuit is also presented.