Pluto Instruments

PCS series

PCS series is a specialized version that can cover the regime where PCG-380F might not reach. Their circuit topologies are not fixed and are flexible to reflect our customers' extraordinary requests. Basically, PCS series has three categories of low noise (LN), precise (P), and fast (F). Though all the categories would be balanced to reach our customers' satisfaction. We need to know what you do and what you need very clearly for this line of amplifiers. PCS series are designed individually and handcrafted one by one. We may not guarantee we always solve your problems.

PCS-LN

low noise

Low noise is essential for a high-performance current preamplifier.
Unless it is an ultimate noiseless current preamplifier, the best way to demonstrate noise performance is to compare it with a widely used time-proven market-leading one. The figure below shows shielded open input-referred total current noise density acquired from our PCS-LN (red) and the market reference (blue) at the same sensitivity of 1 nA/V (1 GΩ feedback resistor). To match the signal bandwidth ~5 kHz of the market reference at the sensitivity, PCS-LN's bandwidth is also reduced to ~5 kHz from its ~40 kHz full bandwidth by using a 1 pole low pass filter. The input voltage noise, which makes a significant noise contribution at the high-frequency range by coupling with the input capacitance, is typically tuned to be below 2 nV/√Hz at 1 kHz. It can be below 1 nV/√Hz if necessary. Since the input capacitance due to cold cables and thermal anchoring capacitors cannot be avoided by locating the preamplifier close to the signal source, the input voltage noise density may need to be as low as possible.

PCS-P

precise

Applying a voltage across isolated quantum states as shown in the above figure may be tricky. Though a precise 20bit (1ppm) DAC is available in the market, the input offset voltage of the current preamplifier could spoil the precision over time due to its drift. Observing the quantum states at 100 mK at which the level spacing of the states might be in the range of 10 μV, the offset drift should be less than that.

PCS-P features a low input offset voltage and its drift over time as shown below regardless of your laboratory temperature.

PCS-F

fast

PCS-F(with a 1GΩ feedback resistor) can make ~100kHz bandwidth. The figure below demonstrates its frequency response. From the rise time(10%-90%)of the output wave, the -3dB signal bandwidth has '0.35 / rise time' relation for the Gaussian response oscilloscope.

Adding an extra 1nF capacitance between the input and the ground of the PCS-F, it can still make ~100 kHz bandwidth. Pluto Instruments can deal with higher sensitivities(up to 10GΩ) for high speed and heavy input capacitance burden.