Apian current amplifier DDPCA-300 - Features

1. Low noise: minimum 0.4fA peak-to-peak value

2. The adjustable gain is from 10 4 to 10 13 V/A

3. 240 dB dynamic range for sub-FA to mA measurements

4. Pretension adjustable tension of the test object

5. Compact design, can be used directly at the signal source

6. It can be set manually or through a digital interface

The adjustable apF amplifier DDPCA-300 is the newest member of a variety of low noise transimpedance amplifiers. The extraordinary design achieves excellent input noise figures as low as 0.2 fA/√Hz and 0.4 fA peak-to-peak.

A wide range of 0 4 to 10 13 for manual or interface V/A can be set. As a result, the amplifier has a dynamic range of more than 240 dB and allows measuring currents from subfemtopicals to milliamps by simply switching the measurement range. The compact design can be used directly at the signal source, thus avoiding signal impairments caused by long cables. To optimize the SNR, the device can be adapted to various measurement conditions using integrated signal filters. Even at the highest gain levels, the bandwidth is suitable for directly measuring individual femtoampas without external averaging (see FIG. 1).

Drift and offset currents cause measurement errors and baseline shifts, especially in the flight safety range. Therefore, the design of DDPCA-300 is optimized for high long-term stability and very low drift. Figure 2 below shows the drift behavior of the amplifier over a long period of time. A drift value of less than 0.5 fA was achieved over 7 hours. If the baseline offset cannot be avoided, for example due to strong temperature variations, the resulting error current can be compensated by a built-in offset setting.

The high measurement sensitivity of the DDPCA-300 can be used to characterize high-impedance semiconductors, such as MOS and JFETs, and quantum dots. An adjustable bias voltage directly at the input of the amplifier can be used to bring the sample to the correct operating point. The bias voltage was set manually on the amplifier or in the range of ±10 V through the interface. For applications such as photocurrent or charge measurements that do not require a bias voltage, simply turn it off.

* The bandwidth, rise time, and integrated input noise values in the table above apply to the "full bandwidth" signal filter setting. Low peak-to-peak noise values can be achieved by setting "0.7 Hz" or "0.1 Hz" through the filter. A minimum input noise of 0.4 fA peak-to-peak is achieved for gain ranges of 10 12 and 10 13 V/A with the filter set to 0.1 Hz.

The offset can be adjusted by the trimmer. LED overload indicator. The input is protected from transients up to ±2 kV. Output short circuit protection. Supply voltage ±15 V, through 3 pins Lemo ® Socket. Includes a matching connector. Optional PS-15 series power supply. See the datasheet for more details.