Electronics Lab

 
 

Low Noise | High Stability I to V Converter (SP 983)

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. Commercial available I/V converters suffer from higher input voltage noise or lower input voltage stability over temperature. The gain can be selected in decades from 105 up to 109 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 (SP 983a). At the maximum gain (109 V/A) the bandwidth is typical 1.6 kHz and at the minimum gain (10V/A) reaches 600 kHz. By applying an external voltage the input offset voltage can be varied within ±100 mV.

The device can be equipped with two different J-FETs in the input stage:

1) STANDARD: LSK389A

PRO: Lower input current noise (significant in the 108 and 109 V/A ranges) CON: Slightly higher input voltage noise. Smaller gain-bandwidth-product (68 MHz) increases output noise at large input-capacitances. 

Data Sheet STANDARD 

2) HIGH-GBWP: IF3602

PRO: Slightly lower input voltage noise. Lager gain-bandwidth-product (620 MHz) makes output noise significant smaller at large input-capacitances. CON: Higher input current noise (significant in the 108 and 109 V/A ranges) 

Data Sheet HIGH-GBWP

 

Low Noise | High Stability I to V Converter (SP 983c)

The version SP 983c of the "LNHS I to V Converter" is completely the same as the SP 983 above, only that the external applied input offset voltage is internally subtracted and is no longer on top of the output signal.
This option was demanded by users sweeping or altering the input offset voltage of the "LNHS I to V Converter".

The device can be equipped with two different J-FETs in the input stage:

1) STANDARD: LSK389A

PRO: Lower input current noise (significant in the 108 and 109 V/A ranges)CON: Slightly higher input voltage noise. Smaller gain-bandwidth-product (68 MHz) increases output noise at large input-capacitances.

Data Sheet STANDARD (SP 983c)

2) HIGH-GBWP: IF3602

PRO: Slightly lower input voltage noise. Lager gain-bandwidth-product (600 MHz) makes output noise significant smaller at large input-capacitances.
CON: Higher input current noise (significant in the 108 and 109 V/A ranges)

Data Sheet HIGH-GBWP (SP 983c)