These high gain (10E13V/A) modules amplify the very small signals from charge generators such as the ‘tuning-fork’ quartz crystal output form atomic force microscopes, pyro- and piezoelectric detectors, and charged particle beam monitoring, for example. The HQA series is optimised for sinewave signals from AC coupled charge sources.
These charge amplifiers convert the current (charge per unit time) to voltage. The HQA-15M-10T is designed for AC modulated charge sources with an amplifier gain of 10 V/pC and bandwidth 250 Hz to 15 MHz, however, custom amplifiers are available. Often a charge amplifier needs a reset mechanism to avoid an overload of the amplification stage. Designed for AC modulated signal sources with no average DC background current, the charge in these applications is alternating positive and negative and therefore no separate reset is required since the average current is zero.
With extremely low input noise (40E-21C/√Hz and 700pV/√Hz) these modules are ideal for AC coupled charge sources, for applications that include; pre-amplifiers for Pyroelectric (Pyros) and Piezoelectric detectors, Atomic Force Microscopy (AFM / SFM), nanoscopes, charged particle beam alignment using the charge amplifier as a pre-amp for ion detectors such as a Faraday cup or other ion detector.