PWM-A/D conversion: a flexible and low-cost solution for transducer linearization

This paper proposes a linearization technique based on a pulse width modulated (PWM) analog-to-digital (A/D) converter. The hardware and software associated with the converter are specially tailored to linearize transducer characteristics by varying the duty cycle of the PWM signal in each of the input range sub-intervals (IRS) that are considered for a given application. The proposed solution can also provide an automatic variable range selection and continuous auto-calibration capabilities that can be used to correct offset and gain errors. Simulation and experimental results are used to confirm the theoretical expectations of the proposed solution for nonlinear transducer interfacing.