Can be remotely controlled via RS232 interface, with operating modes including high-speed mode and low-noise mode. Gain is adjustable from 1×10^3 to 1×10^11, with a maximum bandwidth of 500 kHz.

Transimpedance gain ranges from 10^3 to 10^11 V/A
Input noise as low as 4.3 fA/√Hz
Bandwidth up to 500 kHz
Fall time as fast as 700 ns
Adjustable bias voltage
Manual and remote control

9-stage variable gain: 10^3 to 10^11 V/A, ultra-low noise down to 4 fA/√Hz, bandwidth DC-500 kHz, adjustable bias and offset, variable AC/DC coupling, 10 Hz low-pass filter for convenient DC measurements, digital computer interface or remote control. Suitable for photodiodes, scanning tunneling microscopy, particle detectors, pre-amplification for lock-in amplifiers, and A/D conversion.

Low-noise current amplifier
The DLPCA-200 variable gain transimpedance amplifier offers numerous features for a wide range of applications requiring the conversion of small currents into usable voltages. It is ideal for time-resolved current and charge measurements (down to the microsecond range) and serves as a preamplifier for photodiodes or lock-in systems. The DLPCA-200 provides variable transimpedance gain from 10^3 to 10^11 V/A, enabling sensitive measurements of currents from sub-picoamperes to milliamperes. Its switchable AC/DC coupling, 10 Hz low-pass filter, and adjustable offset control allow the amplifier to adapt to varying measurement tasks and signal conditions. An adjustable bias voltage, connected to the shield layer of the input socket, optimizes the speed and noise performance of external photodiodes connected to the amplifier input.

All functions can be set manually via switches or remotely via an optically isolated interface. All of this is housed in a robust, compact EMI-shielded enclosure designed with user needs in mind, ensuring trouble-free operation even in very harsh and noisy environments.
Bandwidth and frequency response are independent of source capacitance
Unlike other available amplifiers, the DLPCA-200 does not require special adjustments, such as frequency compensation for different signal sources. Even for high source capacitances up to 1 nF, the gain remains constant, and the frequency response is exceptionally flat. The carefully designed amplifier and thorough testing of each unit before shipment avoid common issues such as gain peaking or even oscillation.
Additionally, the DLPCA-200 delivers high speed even at high gain settings. At the maximum gain setting of 10^11 V/A, it provides a 3 dB bandwidth of 1.1 kHz and a rise time of 300 μs. For low-frequency applications that do not require full bandwidth, the device features a switchable 10 Hz low-pass filter that eliminates broadband noise, enabling accurate, ultra-low-noise DC current measurements down to the nanoampere range.
Application Areas
Photodiode and photomultiplier amplification
Scanning tunneling microscopy (STM)
Spectroscopy
Beam monitoring in particle accelerators/synchrotrons
Ionization detectors
Preamplifiers for lock-in amplifiers, A/D converters, etc.