Lock-in Amplifier/Preamplifier

Programmable Current Amplifier

CA5351

Features

 

High Gain · Wide Bandwidth

1010 V/A: DC to 14 kHz, 109 V/A : DC to 70 kHz
The model CA5351 achieves a measurement system with both high gain and wide bandwidth, that cannot be found anywhere else. The bandwidth is from DC to 500kHz with a response time of 0.7 μs (gain: 106 V/A or less), so high-speed signal amplification is possible.

 

 

Adjustable Gains 103 to 1010 V/A

103/104/105/106/107/108/109/1010 (V/A) 8 selectable amplification ranges in decade increments, which allows the most suitable gain setting according to the sensor used and measurement environment.

 

Fast Response · Stable Operation

A high-speed response of 0.7 μs is possible with a gain of 106 V/A.
Model CA5351 can process fast pulse signals in optical system measurements.
Resonance does not occur even in the presence of cable or sensor capacitance becaue of its unique input circuit design and technology.
Also there is no overshoot or ringing in the response of pulse input.
Fast response, wide bandwidth and stability towards input capacitance makes this model suitable for various types of sensors.

 

 

Fast Response

When gain is 106 V/A, the rise time is 0.480 μs.

 

 

 

Pulse Response

Gain: 109 V/A, Cs: Input-GND capacitance

 

 

 

Wide Input Current Range Coverage For Various Types of Sensors

■ Input current range of CA5351 (S/N ratio: 20dB or more)

 

Current Suppression ±8 nA to ±8 mA

In photoelectric conversion elements such as photodiode and phototransistor, a small current called dark current flows through even when there is no incident light.
In high-gain current amplifiers, when a small DC current input is amplified to a large voltage output, the amplifier becomes saturated, which makes the measurement impossible.
The model CA5351 also incorporates a stable and low noise suppression current supply with high resolution. This current supply can add or offset the input current.
For example, by eliminating dark current or leakage current, it can cause higher SN ratio to make the signals detectable. The "Auto Suppression" function automatically changes the current suppression range even if unwanted DC current fluctuates.

 

Example: When 10μA DC current superimposed on the signal

● No Current Suppression

Output saturates when the gain is more than 106 V/A

 

● With Current Suppression

By eliminating 10μA of the current, the gain can be set to 106 V/A, therefore it becomes possible to measure more detailed fluctuations of signals.

 

 

Low Noise Built-in Variable Filter and Low Noise DC Power Supply

The Model CA5351 has achieved the ultimate low noise value with an equivalent input noise of 2.5 fA/√Hz (at 1010 V/A, 55 Hz)
In addition, a built-in filter is incorporated with 12 settings in 1 to 3 sequences within the response speed of 1μs to 300 ms, which eliminates the noise and improves the SN ratio.
The optimum SN ratio and response speed can be used for different applications.
Furthermore, the incorporated DC low noise power supply utilizes NF's very unique technology in order to pursue and qualify the required low noise level for small current amplifications.

 

 

 

High-quality Performance Supported with Data

The Model CA5351 offers wide bandwidth, high gain and low noise all at the same time, which allows the greatest performance in making tradeoffs.
In the below graph, it shows the comparison data of the Model CA5351 vs. products of other manufacturers.
Horizontal axis shows the higher the cutoff frequency is, the wider the bandwidth is.

( Data by NF, September 2020)

 

Other Functions

 

 

Display Backlight Brightness

4 levels of brightness adjustable or OFF
It can be used in experiments that are sensitive to light.

 

 

Up to 10 savable settings

 

 

Overdetection

Detects excessive signals and displays the conditions.
Detects current-voltage converted signals (input overdetection) and output connector signals (output overdetection) and displays them separately.

Features

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