Fig. 4.

Temperature-dependent and time-dependent voltage-clamp measurements. A 1-GΩ resistor was voltage clamped at 100 mV, producing a set current of 100 pA (dashed line). A: correction of temperature-dependent voltage-clamp measurements. The uncorrected current measurements (squares) vary predictably with temperature. A second-order polynomial (solid line) is used to correct the measurements based on the reading from the on-chip temperature sensor. The corrected measurements (circles) lie within ±3% of the true current over a temperature change of 21°C. B: time drift of voltage-clamp measurements. Over a period of 120 min, the measured current deviated by less than ±3% (circles) from the set current (dashed line).