Low Noise | High Stability I to V Converter
The LNHS I to V Converter combines low input voltage noise with high stability and low drift input voltage (< ±0.2 μV/K). This combination is very important for measurements on samples at temperatures near the absolute zero. Other available I to V converters suffer from higher input voltage noise or lower input voltage stability over temperature. The gain can be selected in decades from 10^5 up to 10^9 V/A and the low-pass filter can be adjusted between 30 Hz and 100 kHz. These settings can also be done remotely by using the Remote Control Interface. At the maximum gain (10^9 V/A) the bandwidth is typical 1.6 kHz and at the minimum gain (10^5 V/A) reaches 600 kHz. By applying an external voltage the input offset voltage can be varied within ±100 mV. The externally applied input offset voltage is internally subtracted and does not go on top of the output signal.
Output ground isolated from case and computer interface (ground provided by shield of cable coming from experiment) makes it easy to avoid ground loops even without use of batteries and to use the instrument in a low noise setup.
The device can be equipped with two different J-FETs in the input stage:
PRO: Lower input current noise (significant in the 10^8 and 10^9 V/A ranges)
PRO: Slightly lower input voltage noise. Lager gain-bandwidth-product (600 MHz) makes output noise significant smaller at large input-capacitances.