• Fast
  • Wide dynamic range
  • Compact

The transimpedance amplifier TZA400 is designed for precise measurement of current, from pA to mA. The output is a voltage linearly proportional to the input current. 

The gain of the TZA400 is controlled via a hard-wire interface on the back panel.

  • Interface: Hard-wire (DB25)
  • Rise time: 1µs (G≤5×105); 4µs (higher gains)
  • Noise equivalent current: 500 p(ARMS) 
  • Gain control: 16 gain ranges in 1-2-5 pattern or
    4 gain ranges in decade spacing

PRINCIPLES OF OPERATION

The TZA400 measures small currents e.g. optical power via a photodiode. Photodiodes are useful for power measurement in the visible and near infra-red due to their inherent sensitivity and speed of measurement.

Photodiodes produce a current which is proportional to the incident light power over a wide dynamic range.

The current is converted to a voltage through a precise transimpedance amplifier. This amplifier is very linear over the full measurement range of the device. The TZA400 has optionally 4 or 16 gain ranges. The switch is a semiconductor device, free from degradation.
The analogue output signal is available at the BNC connector on the front panel an on the appropriate line on the interface port on the back panel.

FIELDS OF APPLICATION

These transimpedance amplifiers are particularly useful for the measurement of current from photodiodes. The output is a voltage linearly proportional to input current and thus, to input power in photodiode monitoring applications. The fast response time at high signal-noise ratio makes the TZA400 series particularly useful in systems control feedback loops.

These amplifiers have a particularly high sensitivity and large dynamic range. There are 16 gain ranges covering 5 decades of gain in a 1-2-5 pattern. The gain-to-gain accuracy of <1% allows confident measurements of power curves over the full range of sensitivity of the device: 6½ decades of measurement range. Thus even very demanding measurements such as the accurate and high speed, real-time determination of polarization extinction ratio becomes a simple task.

The TZA400 series is insensitive to electromagnetic interference by design, an important factor when working in „dirty“ industrial environments. These units are provided in a modular 19“ rack mount system.

ParameterConditionsMinTypMaxUnits
Input
Current ranges (full scale)Maximum range3.7mA
Minimum range37nA
Noise equivalent current (NEPRMS)Range: 3.7mA

2.5

µA
Range: 37nA

500

pA
ConnectorsBNC (Adapters for other connector systems available)
Output03.7V
FunctionLinear analogue : Vout = scale factor x Iin
ConnectorsBNC (Adapters for other connector systems available) und DB25
Output scale with 16 range option, range:3.7mA
1.85mA
740µA
370µA
185µA
74µA
37µA
18.5µA
7.4µA
3.7µA
1.85µA
740nA
370nA
185nA
74nA
37nA
1
2
5
0.01
0.02
0.05
0.1
0.2
0.5
1
2
5
0.01
0.02
0.05
0.1
V / mA
V / mA
V / mA
V / µA
V / µA
V / µA
V / µA
V / µA
V / µA
V / µA
V / µA
V / µA
V / nA
V / nA
V / nA
V / nA
Output scale with 4 range option, range:3.7mA
370µA
37µA
3.7µA
1
0.01
0.1
1
V / mA
V / µA
V / µA
V / µA
Output range (full scale)10V
Rise / Fall time (10% – 90%)Source capacitance < 100pF1µs
Setting time (1%)Source capacitance < 100pF2µs
Accuracy± 1%
Output impedance50Ω
Logic
Current required for switchingHI = 5V
LO = 0V
-1005
0
100nA
Dead time during change of range2 (Limited by setting time. The logical switch is complete within 20ns.)µs
Power supply
TypeWall plug (supplied)
Dimensions
1 channel103 x 45 x 116 (w x h x l)mm
4 channels103 x 106 x 116 (w x h x l)mm
19″- rack modules3U

  • Number of gains: 4, 16
  • Case: gull wing, 19″ rack module
  • Number of channels: 1, 2, 3, 4

None.

Transimpedance Amplifier TZA400 1

Artifex Software Development Kit

The SDK is a fixed, free component when purchasing a device.

It comes with the source code of the application program (in VB.net) and a LabView VI with the basic functions of the instrument. A description of the communication with the devices and a list of the commands used is also included.

For some devices (currently LDD100, LIV120 in preparation) there is a dll file (library file) with documentation and exemplary applications in VB.net and LabView.

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