4 MHz Low Noise Gain High-Speed Weak Current Signal Amplifier HCA-4M-500K-C

High Frequency

Component users often encounter issues caused by poor amplifier design, such as unwanted oscillations, poor grounding, nonlinearity, and loss of gain and bandwidth. FEMTO high-frequency amplifiers are designed to address these problems. FEMTO high-frequency amplifiers are insensitive to source parameters and input wiring, strictly adhering to their specifications. Even with source capacitances as low as 2 nF (applicable to HCA-1M-1M-C), there are no unwanted oscillations, gain, or bandwidth losses.

Bandwidth Unaffected by Source Capacitance

Just a few picofarads of source capacitance can significantly reduce the bandwidth of high-frequency current amplifiers. However, FEMTO current amplifiers do not have this limitation and are unaffected by source capacitance. No frequency tuning is required; bandwidth and gain remain constant within the maximum source capacitance range specified for each model.

"C" Models

Amplifier models marked with the additional letter "C" are optimized for extremely high-capacitance sources (down to nanofarads). Their larger sensitive layer area allows for recording fast signals as low as nanoseconds. For detectors with capacitances greater than 2 nF, FEMTO offers custom models.

Transimpedance Amplifiers with Adjustable Bias Current and Delay

FEMTO HCA transimpedance amplifiers offer high flexibility and allow precise adjustment of bias voltage and delay via potentiometers. The wide range of adjustable input current delay maintains dynamic range even for signals with large DC components. The output offset voltage can be precisely adjusted via a potentiometer in the range of -12 V to +12 V.

Key Features:

Input noise as low as 270 fA/√Hz;

Bandwidth up to 400 kHz;

Gain up to 10^6 V/A;

Flat frequency response;

Stable and adjustable bias voltage output for biasing external photodiodes;

Housing with electromagnetic interference protection.

Key Applications:

Spectroscopy;

Scanning tunneling spectroscopy;

Ionizing radiation detectors;

Pyroelectric and piezoelectric receivers.

Output voltage ±1.5 V, impedance 50 ohms. Offset adjustable via potentiometer. Output short-circuit protection. Adjustable offset output (-12 V ... +12 V) for offsetting photodetectors. Power supply via 3-pin Lemo® connector. Power cable included. Optional PS-15 power supply available. For more information, refer to the datasheet.

Note: The maximum detector capacitance value indicates that the specified 3 dB (±15%) bandwidth is guaranteed within this range. Larger capacitance values are also feasible but have minimal impact on bandwidth and frequency response.

*For high-frequency models HCA-100M-50K-C, HCA-200M-20K-C, and HCA-400M-5K-C, if the source capacitance reaches the above values, the bandwidth may decrease to 25% of the nominal value. The maximum source capacitance values are specified. For these models, short input cables and the use of low-capacitance signal sources are crucial. For more information, refer to the datasheet or contact us.