Circuit arrangement including digital-to-analog current converters

摘要

A circuit checks the value and the existence of an external load of a digital-to-analog current converter. A first comparator compares a digital word to be converted, with a comparison data word. The output signal of the first converter indicates during which periods the digital data word is greater and during which periods it is smaller than the comparison data word. A second comparator compares the voltage at the output of the converter with a reference voltage. The output signal of the second converter indicates during which periods the output voltage is greater and during which periods it is smaller than the reference voltage. A comparison circuit checks the existence and the value of the output load by comparing the time periods indicated by the output signals of the two converters. Thus, a conclusion about the existence and the value of the output load is possible at any time.