Features

• Input noise down to 180 aA/√Hz
• Bandwidth up to 400 kHz
• Gain up to 10¹³ V/A
• Flat frequency response
• EMI-shielded case

 

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

• Photodetector amplifier
• Spectroscopy
• Scanning tunneling microscopy
• Ionization detectors
• Pyro- and piezoelectric detectors

 

Model	3-dB Bandwidth (DC ...)	Noise Current [/√Hz]	Transimpedance (Gain)	Rise/Fall Time	Datasheet
LCA-2-10T	2 Hz	0.18 fA	1012 and 1013 V/A	200 ms	212 kB
LCA-30-1T	30 Hz	0.5 fA	1 x 1012 V/A	12 ms	259 kB
LCA-30-200G	30 Hz	0.5 fA	2 x 1011 V/A	12 ms	259 kB
LCA-200-100G	200 Hz	1.5 fA	1 x 1011 V/A	2 ms	258 kB
LCA-200-10G	200 Hz	1.5 fA	1 x 1010 V/A	2 ms	258 kB
LCA-1K-5G	1 kHz	3 fA	5 x 109 V/A	400 µs	257 kB
LCA-2K-2G	2 kHz	4.5 fA	2 x 109 V/A	200 µs	259 kB
LCA-4K-1G	4 kHz	6.5 fA	1 x 109 V/A	100 µs	259 kB
LCA-10K-500M	10 kHz	10 fA	5 x 108 V/A	40 µs	260 kB
LCA-20K-200M	20 kHz	14 fA	2 x 108 V/A	20 µs	260 kB
LCA-40K-100M	40 kHz	19 fA	1 x 108 V/A	10 µs	259 kB
LCA-100K-50M	100 kHz	30 fA	5 x 107 V/A	4 µs	260 kB
LCA-200K-20M	200 kHz	40 fA	2 x 107 V/A	2 µs	260 kB
LCA-400K-10M	400 kHz	65 fA	1 x 107 V/A	1 µs	258 kB

 

NOTE: Bandwidth and frequency response are 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. 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.