德国FEMTO可变增益电流放大器DDPCA-300

DDPCA-300可变增益电流放大器
***大峰值噪声0.4 fA
9级可变增益：104~1011 V/A
240 dB Dynamic Range for Sub-fA to mA Measurements
Adjustable Voltage on Input for DUT Biasing
Compact Housing for Use Close to the Signal Source
Manual and Remote Control
Sub Femto Ampere Sensitivity  

The variable gain sub femto ampere amplifier DDPCA-300 is the latest addition to FEMTO's broad range of low noise transimpedance amplifiers. Its exceptional design achieves input noise values down to 0.2 fA/√Hz and 0.4 fA peak-peak. The gain can be set over a very wide range from 104 up to 1013 V/A either manually or by a remote interface. Thus, the amplifier covers a large dynamic range of more than 240 dB for the measurement of currents from sub femto amps up to milli amps by simply switching the gain range. The compact housing is optimized for use close to the ** source avoiding ** perturbations or noise pick-up due to long cables. Various filters are integrated to adapt the amplifier bandwidth to varying ** conditions. Thus, the ** to noise ratio and measurement speed can be optimized by selecting the proper filter setting for a specific application. And even in the highest gain settings the measurement speed is sufficient to measure femto amp currents in real-time without the need for external averaging or long test periods (see figure 1 below). 

 
Low Drift for Stable Long-Term Performance  

At the femto ampere level drift and offset currents can easily cause measurement errors and shifting baselines. The design of the DDPCA-300 is optimized for long-term stability and extremely low drift. The below figure shows the amplifier's baseline drift of less than 0.5 fA measured over a period of more than 7 hours. In case of inevitable (e.g. temperature related) offsets an trimpot is provided for cancelling unwanted offset currents and for nulling of the baseline. 

 
Device Characterization by Source Biasing  

The very high sensitivity of the DDPCA-300 can be utilized in low current applications like characterization of high resistance semiconductors (e.g. MOS or JFETs) or quantum-dot devices. An adjustable voltage is supplied directly at the amplifier input for biasing the device under test (DUT). Changing the bias voltage manually or through the remote interface in the range of +/- 10 V allows the characterization of the DUT for different bias voltages in spectroscopic measurements. For applications not requiring a bias voltage like photocurrent measurements or beam monitoring in particle physics the bias voltage can be easily disabled.

 
Applications 
Photo and Ionization Detector Amplifier
I/V Characterization of MOS and JFET Structures 
DC Measurement of Ultra Low Currents 


Quantum and Biotech Experiments 
Spectroscopy 
High Resistance Measurements 
Easy to Use Femto Amp Add-on to Existing Digital Voltmeter or A/D Converter