Design Of A 14 Bits S/RDC

In this thesis, the algorithm of a 14 bits synchro/resolver to digital signal converter (S/DRC) has been studied. Nowadays in the modern servo system for industry, it is very popular to use an alternative current servo system, especially when high-performances, such as high accuracy and high resolution, are required. There are two kinds of servo system drivers: IM (induction motor) and PMSM (permanent magnet synchronous motor). If synchro or resolver, two kinds of PMSM location sensors, is used to be the location sensor of servo system, then an S/DRC is necessary to convert the analog sin/cos angular signal to digital signal. So in a servo system, the S/RDC is employed as an interface of the location detector module and digital signal processor module. The developing tendency of S/RDC is high accuracy, high resolution and multi-channel.Up to now, all kinds of single chip S/RDC can perform as either SDC or RDC, even those latest announced products. But the chip proposed in this thesis is a special S/RDC, which can not only perform as both SDC and RDC and can also identify the modes of input signal automatically. This S/RDC can convert high voltage(±120V_max + 26V_ac) synchro mode input signal and resolver mode input signal into 14 bits binary digital signal. In addition, a built-in-test facility is used in failsafe system to provide an indication of whether the converter is tracking accurately. Generally, this chip is mainly consisted of three modules: signal pre-process module, signal converting module and built-in-test module. In the signal pre-process module, a differential circuit has been adopted to isolate and step down the input signal, and also, a solution of employing a peak detector circuit to identify the modes of input signal has been proposed. In the chapter four, the structure of a...