Ultra Low Noise Current Amplifier Series LCA

Ultra Low Noise
Current Amplifier
Series LCA

Why Use a Preamplifier Module?
Unlike desktop amplifiers, preamplifier modules provide gain close to the detector before the signal-to-noise ratio significantly decreases due to cable capacitance and noise pickup. Signal processing and measuring after pre-amplifying has no effect on the signal/noise performance.
Gain and Noise
In order to achieve an extremely low noise performance very high gains were chosen, while nevertheless minimizing the associated bandwidth reduction. Thus, as a result of our sophisticated development efforts we can offer a professional "High-End" Current Amplifier line. The noise performance of our products surpasses by far that of conventionally designed OpAmp current-to-voltage converters at the corresponding bandwidth.
Bandwidth and Frequency Response
FEMTO Current Amplifiers show almost ideal behavior without the need for special adaptations or frequency compensations. Bandwidth and frequency response are independent of source capacitance up to 10 nF. No gain peaking will occur.
Preamplifier for Lock-Ins
Lock-In-Amplifiers usually have a special current input. By using instead a low noise preamplifier in noise limited experiments even the sensitivity and speed of a DSP Lock-In is strongly increased. Femtoampere currents can then be measured within a few milliseconds.
Applications
Photodetection with PMTs and Photodiodes Spectroscopy Scanning Tunneling Microscopy Ionization Detectors Pyro- and Piezoelectric Detectors

Model	3-dB Bandwidth (DC ...)	Noise Current [/√Hz]	Transimpedance (Gain)	Rise/Fall Time	View and Download Datasheet
LCA-2-10T	2 Hz	0.18 fA	10¹² and 10¹³ V/A	200 ms	80 kB
LCA-30-1T	30 Hz	0.5 fA	1 x 10¹² V/A	12 ms	261 kB
LCA-30-200G	30 Hz	0.5 fA	2 x 10¹¹ V/A	12 ms	261 kB
LCA-200-100G	200 Hz	1.5 fA	1 x 10¹¹ V/A	2 ms	261 kB
LCA-200-10G	200 Hz	1.5 fA	1 x 10¹⁰ V/A	2 ms	261 kB
LCA-1K-5G	1 kHz	3 fA	5 x 10⁹ V/A	400 µs	125 kB
LCA-2K-2G	2 kHz	4.5 fA	2 x 10⁹ V/A	200 µs	125 kB
LCA-4K-1G	4 kHz	6.5 fA	1 x 10⁹ V/A	100 µs	261 kB
LCA-10K-500M	10 kHz	10 fA	5 x 10⁸ V/A	40 µs	261 kB
LCA-20K-200M	20 kHz	14 fA	2 x 10⁸ V/A	20 µs	261 kB
LCA-40K-100M	40 kHz	19 fA	1 x 10⁸ V/A	10 µs	261 kB
LCA-100K-50M	100 kHz	30 fA	5 x 10⁷ V/A	4 µs	261 kB
LCA-200K-20M	200 kHz	40 fA	2 x 10⁷ V/A	2 µs	261 kB
LCA-400K-10M	400 kHz	65 fA	1 x 10⁷ V/A	1 µs	261 kB
NOTE: Bandwidth and frequency response are absolutely independent of Detector Capacitance. Guaranteed and 100 % tested up to 10 nF for each amplifier (up to 1 nF for LCA-400K-10M).
Output voltage ± 10 V @ >10 kΩ load. Offset adjustable by trimpot. AC coupling optionally available as customized version. Output short-circuit protected. Power supply via 3-pin LEMO socket. A mating connector is provided with the device. Optional power supply PS-15 available. For further information please view the datasheet or contact FEMTO.