A sensitive analog comparator

A strobed, sensitive analog comparator has been developed for use in the NBS Data Converter Test Facility. The comparator has a sensitivity of 1.5 μV and a response time of 30 μs to within 10 μV, following input steps up to 20 V. Signal voltages up to ±10 V are compared with reference voltage levels of opposite polarity, using a precision resistive divider. The input offset has a temperature coefficient of -1 μV/°C and changes less than ±5 μV under worst case dynamic conditions. Following a strobe pulse, the digital output is retained until the next strobe pulse. Optical isolators provide isolation between the analog and digital circuits.