Precision low-level resistance measurements in the most demanding conditions

The AMS220 Voltage Controlled Current Source with Active Common Mode Rejection brings a unique possibility for researchers to perform low-level electrical measurements requiring precise current excitation at the negligible level of common mode voltage. The AMS220 is preferentially designed for low-noise resistance  measurements using a lock-in amplifier, where in combination with the high-sensitivity lock-in amplifier measurements of very low resistances (less than 1 mOhm) become a routine even in the most demanding conditions (e.g., temperatures below 500 mK). This is feasible due to the combination of the lock-in technique, which enables to perform very-low voltage measurements also in the background of significant disturbance signals, and the unique (patented) AMS220 architecture, which ensures active rejection of common mode voltage that arises at current excitation of the load. In this sense, the AMS220 opens new experimental possibilities especially for researchers working in the field of superconductivity and electrical transport phenomena.

Alternatively, the AMS220 can be also used in combination with DAQ devices in many types of DC or AC electrical measurements, where well defined current excitation of D.U.T. is required. Applications include e.g., resistance measurements, thermometry, or I-V curves measurements.
AMS220 Voltage Controlled Current Source
with Active Common Mode Rejection
Patented common mode rejection technology
(U.S. #9,285,809 March 2016
Output current to ±50 mA
Voltage-to-current conversion ranges from
1µA/V to 10 mA/V
± 5 V control voltage input range
Low-noise, all analog design
Optimized for use with lock-in amplifiers
Replacement for AC resistance bridges when used with lock-in amplifiers
• Very low resistance masurements down to mK  
   - Superconductivity research
   - Hall effect phenomena
• Higher harmonic detection in resistance
• Thermometry/calorimetry
• Mutual inductance measurements
AC and DC electrical measurements with DAQ devices
• Cost-effective solution for resistance measurements and  thermometry
I-V curves measurements
Replaces floating current sources in resistance measurements