Users of high frequency components are often confronted with problems including unwanted oscillation, poor ground shielding, nonlinearities, gain peaking and bandwidth reduction caused by poorly designed amplifiers. FEMTO High Frequency Amplifiers have been designed to eliminate such unwanted problems. Insensitive to signal source parameters and input wiring, FEMTO High Frequency Amplifiers perform meticulously within their specifications. No gain peaking, oscillation or significant bandwidth reduction will occur, even for source capacitances up to maximum 2 nF (for the HCA-1M-1M-C).
Merely a few picofarads of source capacitance can drastically decrease the bandwidth of high frequency current amplifiers. However, FEMTO Current Amplifiers do not have this limitation and are not influenced by a wide range of source capacitances. No frequency compensation or special adaptation is needed and the bandwidth and gain are constant up to the maximum source capacitance specified for each model*.
Amplifier models shown with an additional "C" are optimized for handling very large source capacitances up to nanofarads. They are very useful for measuring fast signals down to nanoseconds with large area detectors. For detectors with even more than 2 nF capacitance we offer custom designed models. Please contact us for details.
For a high degree of flexibility FEMTO's HCA Current Amplifiers offer precise offset and bias control by two trimpots. The wide range of the adjustable input offset current compensation preserves full dynamics even for signals with large DC-components. The voltage at the bias-output can be adjusted precisely from -12 to +12 Volts using the multi turn bias-trimpot.
Model |
3-dB Bandwidth (DC ...) |
Noise Current [/√Hz] |
Transimpedance (Gain) |
Rise/Fall Time |
Max. Source Capacitance |
View and Download Datasheet |
HCA-1M-1M | 1 MHz | 270 fA | 1 x 106 V/A | 350 ns | 50 pF | 273 kB |
HCA-1M-1M-C | 1 MHz | 3.5 pA | 1 x 106 V/A | 350 ns | 2 nF | 273 kB |
HCA-2M-1M | 2 MHz | 340 fA | 1 x 106 V/A | 180 ns | 25 pF | 273 kB |
HCA-2M-1M-C | 2 MHz | 3.5 pA | 1 x 106 V/A | 180 ns | 1 nF | 273 kB |
HCA-4M-500K | 4 MHz | 490 fA | 5 x 105 V/A | 90 ns | 15 pF | 273 kB |
HCA-4M-500K-C | 4 MHz | 3.5 pA | 5 x 105 V/A | 90 ns | 500 pF | 273 kB |
HCA-10M-100K | 10 MHz | 1.1 pA | 1 x 105 V/A | 35 ns | 15 pF | 273 kB |
HCA-10M-100K-C | 10 MHz | 3.5 pA | 1 x 105 V/A | 35 ns | 150 pF | 273 kB |
HCA-20M-100K-C | 20 MHz | 3.5 pA | 1 x 105 V/A | 18 ns | 50 pF | 273 kB |
HCA-40M-100K-C | 40 MHz | 3.7 pA | 1 x 105 V/A | 10 ns | 30 pF | 273 kB |
HCA-100M-50K-C | 100 MHz | 3.9 pA | 5 x 104 V/A | 3.5 ns | 20 pF* | 241 kB |
HCA-200M-20K-C | 200 MHz | 5.3 pA | 2 x 104 V/A | 1.9 ns | 8 pF* | 236 kB |
HCA-400M-5K-C | 400 MHz | 20 pA | 5 x 103 V/A | 1 ns | 10 pF* | 257 kB |
Output voltage ±1.5 V, @ 50 Ω load. Offset adjustable by trimpot. AC-coupling optional. Output short-circuit protected. Adjustable bias-output (-12 V ... +12 V) for biasing photodetectors. 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.
NOTE: The maximum detector capacitance listed above means that up to this value the specified 3dB-bandwidth (±15 %) is guaranteed. Larger capacitances are also possible, but will slightly influence the bandwidth and frequency response.
* For the ultra fast models HCA-100M-50K-C, HCA-200M-20K-C and HCA-400M-5K-C a reduction in bandwidth up to 25 % of the nominal values might occur if the source capacitance reaches the above noted maximum source capacitance values. Especially for these models short cables at the input and the use of low capacitance sources is of major importance. For further information please view the datasheet or contact FEMTO.
Meet us at the DPG-Spring-Meeting 2019 at TU Rostock from March 13 to 15. You will find us in the Institute of Physics, booth 34.
All FEMTO photoreceivers offered with FS input (round flange with 25 mm diameter) are now also available with 1.035″-40 threaded flange (FST) input – for even more flexibility on the optical bench!
FEMTO® Messtechnik GmbH
Klosterstraße 64
10179 Berlin
Germany
Phone: +49-(0)30-280 4711-0
Fax: +49-(0)30-280 4711-11
Email: info@femto.de
© FEMTO 2019