Current Mode Preamplifiers convert the current output of a photovoltaic Ge, InAs, or InSb detector into a voltage output. They amplify the signal for subsequent use with oscilloscopes, lock-in amplifiers, or A-to-D converters. Three different preamp models each offer specific advantages, depending on detector type and bandwidth requirements. All units (except multi-channel models) have switch-selectable gain.
The PA-7 is an excellent general purpose preamplifier for most high shunt resistance (RD > 25Kohm) detectors, including small area J16 Series Ge and all J16TE2 Series cooled Ge. It has extremely low current noise and current offset. For most applications, the PA-7-70 with high gain of 107 V/A offers best performance and versatility. However, for applications where 107 V/A gain is unusable (due to bandwidth or DC saturation), the PA-7-60 or PA-7-50 are suitable alternatives.