NEW LEAKAGE-COMPENSATION TECHNIQUE FOR SUPERIOR CURRENT-TO-FREQUENCY CONVERSION (10-15A TO 10-8A)

We present a new technique to be used with ultra-low-level current-to-frequency converters (CFC) to enlarge their dynamic range of measurement (by a factor of ten). This technique also enables one to realize a more sensitive (by a factor of ten) CFC (lmin=10-15 A) than all previously relaized one (lmin=10-14 A). This technique is based on the carrier-heating phenomenon in short-channel MOSFETs. Our experimental work showed that this technique permits efficient compensation of CFC leakage current. Additional circuitry may be introduced to provide automatic leakage-current compensation. © 1990 Taylor & Francis Ltd.