Packed with features the Femto DLPCA-200 variable gain transimpedance amplifier is designed for a wide range of applications that require the conversion of small currents into usable voltages. It is ideally suited, for example, for time resolved current and charge measurements down to the µs region and as preamplifier for photodiodes or lock-in systems.

The DLPCA-200 offers variable transimpedance gain from 10³ to 10¹¹ V/A allowing the sensitive measurement of currents in the sub-pico to milli amp range. Its switchable AC/DC coupling, 10 Hz low pass filter and adjustable offset control can be used to adapt the amplifier to varying measurement tasks and signal conditions. An adjustable bias voltage connected to the shield of the input socket is provided to optimize the speed and noise performance of external photodiodes connected to the amplifier input.

FEATURES

• Transimpedance gain from 10^3 to 10^11 V/A

• Input noise down to 4.3 fA/√Hz

• Bandwidth up to 500 kHz

• Rise time down to 700 ns

• Adjustable bias voltage

• Manual and remote control

THE ULTIMATE LOW NOISE CURRENT AMPLIFIER

All functions can be set either manually by switches or through the opto-isolated interface by remote control. All this in a rugged and compact EMI shielded case designed with the user in mind and built to guarantee trouble-free operation even in very rough and noisy environments.

BANDWIDTH AND FREQUENCY RESPONSE INDEPENDENT OF SOURCE CAPACITANCE

Unlike other amplifiers available the DLPCA-200 requires no particular adaptation such as frequency compensation for different sources. The gain stays constant and the frequency response is nicely flat even for high source capacitances up to 1 nF. Common issues such as gain peaking or even oscillations are avoided by the careful amplifier design and thorough testing of the units prior to shipment.

In addition the DLPCA-200 provides high speed even for large gain settings. At the highest gain setting of 10¹¹ V/A it provides a 3 dB bandwidth of 1.1 kHz and a 300 µs rise time. For low frequency applications not requiring the full bandwidth the unit has a switchable 10 Hz low pass filter to eliminate wideband noise and thus allowing accurate and ultra low noise DC current measurements down to femto amps.

APPLICATIONS

• Photodiode and photomultiplier amplifier

• Scanning tunneling microscopy (STM)

• Spectroscopy

• Beam monitoring for particle accelerators / synchrotrons

• Ionization detectors

• Preamplifier for lock-ins, A/D converters etc.

Offset adjustable by trimpot or external control voltage. LED overload indication. Input protected against ±3 kV transients. 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.