The CA5350 programmable current amplifier is a variable gain type, current-input, voltage-output amplifier. Gain can be set from 104 V/A to a maximum of 1011 V/A. In addition, the included current suppression function enables the canceling of the dark current that cannot be avoided with photoelectric conversion elements such as photo-diodes. BNC connectors are used for input and output, so special cables or an external power supply are not required. The various settings, including gain, are easy to perform using the dial and keys on the front panel, and the set values are displayed on the screen. Since the GPIB and USB interfaces make remote control also possible, gain and other settings can be performed from a personal computer, making it easy to configure an automatic measurement system. With its performance, functions and operational ability, this programmable current amplifier supports the current amplification of signals from a variety of current output sensors.
The CA5350 realizes unprecedented high gain and broad bandwidth support from DC to 14 kHz at 1010 V/A, and from DC to 70 kHz at 109 V/A. In addition, it also supports high-speed signals from DC to 500 kHz at 106 V/A or less.
Gain can be set in seven ranges of 104, 105, 106, 107, 108, 109, 1010 (V/A), in x10 increments. This enables the optimal gain setting to match the current and sensor values that vary depending on the measurement conditions. In addition, if an output amplifier gain of x10 is used, a maximum gain setting of 1011 V/A is possible
The fast response of 0.7 µs at 106 V/A gain enables support for fast pulse response signal processing in optical systems. Our unique circuit design technology enables stable operations even with the capacitance of the connecting cables and sensors, eliminating any concerns about oscillation. In addition, overshoot and ringing do not occur even for pulse responses. By achieving both fast response and broad bandwidth, as well as stable operation even with additional capacitance on the input side, the CA5350 supports a variety of sensor types.
For photodiodes and photo transistors, in the absence of incident light, a weak current called a dark current will flow. In a current amplifier with high gain, a small DC current input becomes a large voltage when output, and the amplifier is saturated and measurement becomes impossible. The built-in suppression current source is adjustable to cancel the input of such dark current. The current suppression setting can be selected in six ranges from ±8 nA to ±800 µA. In addition, the auto-suppression function can be used to automatically set the range and current value required to suppress the dark current.
Built-in filters and DC power supply The CA5350 achieves an ultra-low noise with an input-referred noise of 2.5 fA/vHz (at 1010 V/A, 55 Hz). In addition, in order to remove noise components and to improve the signal-to-noise ratio (SN ratio), the built-in filter can be set to a response speed in the range of 1 µs to 300 ms to optimize the SN ratio and response speed depending on the application. And furthermore, in our pursuit of the low noise operation that is essential to the amplification of a weak current, we have adopted a low noise DC power supply in the power supply section using our own unique technology.
Interfaces, input and output terminals The standard-equipped USB and GPIB interfaces support remote control and integration of the CA5350 into an automatic measurement system. Since input and output terminals are provided on both the front and rear panels, you can choose the terminals depending on how you are connecting to sensors or other equipment. In addition, the half-rack size makes the integration of multiple units easy.