摘要 |
<p>An analog-to-digital converter for use with such instruments as two-wire vortex flowmeters. The converter's input terminal, adder, integrator, comparator and flip-flop circuit are connected in series, the output signal of the flip-flop circuit is connected to the converter's output terminal, and the output signal is fed back to the adder through a digital-to-analog converter. Thus the converter outputs a pulse density signal corresponding to the given input signal, serving as a sigma-delta analog-to-digital converter. The comparator's output is isolated from the input of the flip-flop circuit and the output of the flip-flop circuit is isolated from the digital-to-analog converter's input in order to reduce current consumption. <IMAGE></p> |