Fast response digital interface apparatus and method.

摘要

The digital interface divides a digital number (N0) representing the sensor reading into a most significant part (MSB) and a least significant part (LSB). The most significant part is used to determine the pulse width of a sequence of pulses and the least significant part is used to selectively modify the pulses by increasing the pulse width of selected ones of the pulses. A lookup table (54) is used to evenly distribute the lengthened pulses throughout the pulse train. The resulting waveform has a DC component representative of the original digital number which is extracted by low pass filtering. The energy in the non-DC spectral components is appreciably attenuated as compared to the spectrum of a standard pulse width modulated waveform. This makes it possible to use a filter (28) with considerably higher cutoff frequency and with considerably improved response time for a given resolution. <IMAGE>