OPA855 transimpedance amplifier is a high-speed and high-bandwidth IV conversion circuit. The chip has a nominal gain bandwidth product of 8GHz. It is usually used in pulsed light conversion and some weak current detection places. The minimum current resolution of the module is 0.1uA. The module has an analog signal bandwidth better than 200M, compatible and adaptable to most photodiodes PD and avalanche Hz diodes APD. The main chip of the module is TI's high-bandwidth chip OPA855. The operational amplifier has the characteristics of extremely high bandwidth and low bias current. Modules are usually used for high-speed photodetection, light pulse detection and fluorescent substance detection, etc.
Parameters：
Module model: 0PA855 transimpedance amplifier
Module type: current to voltage amplifier
Module power supply voltage: ±2.5V (TYP), ±2.75V (MAX)
Module power supply current: ± 20mA
Input signal form: single-ended current
Input current range: 3mA (MAX) (different feedback resistors correspond to different maximum currents)
Minimum resolution of input current: 0.1uA
Input frequency range: DC- 200MHz (large feedback resistance means smaller bandwidth)
Input impedance: 1K ohm
Output voltage range: 3Vpp (MAX) (the output voltage is within the power supply)
Output current: ±5mA (MAX)
Module output voltage: Vout=-Iin*R1
Module protection: power reverse connection protection
Module specification: 41*37*7mm (length * width * height-PCB size)
Module heating: no heat sink (no heat dissipation required for normal operation)
Module heating factor: excessive supply voltage damages the chip or the module is damaged
Module working temperature: 25C--+75C (industrial grade)
Module features: output positive and negative power LED indication, low bias current
Application range: photoelectric detector, data acquisition front end, weak signal detection, etc.
Module interface type: SMA signal signal input and output, 3. 81-3PIM power card socket
Precautions:
Precautions
(1) The power supply of the module is a positive and negative dual power supply, and the voltage cannot exceed 2.75V.
(2) Since the module is a high-precision device and high-bandwidth module, in order to ensure the signal quality, it is recommended to use our precision linear power supply.
(3) For output signal, it is recommended to use good wire to input and output signals to ensure good grounding. You can use an oscilloscope or a voltmeter to observe the effect. Poor contact or poor quality wires may cause signal attenuation or excessive noise.
(4) Due to the wide signal bandwidth of the module, power supply noise and wiring problems may cause the module to output self-excitation. When the module outputs self-excitation, a 50 ohm load can be used to reduce self-excitation.
Module test chart:
OPA855 transimpedance amplifier is powered by our ultra-low ripple precision linear power supply (±2.5V) to test the photoelectric conversion of PD and APD respectively. The first test method uses our 2CU8300 photodiode PD as the current input of the OPA855 transimpedance amplifier, as the light receiving device, the desktop function signal generator generates a 1MHz sine wave signal to directly drive the light emitting diode to generate an alternating light signal. Then use a photodiode to convert the changing photocurrent into a voltage signal, and then the laser communication effect can be achieved, as shown in Figure 1. Since the module is positive and negative power supply, the direction of the photocurrent can be positive and negative
The second test method uses AD500-8 avalanche diodes from our shop, matched with APD special bias power supply to provide APD bias voltage. The desktop function signal generator generates a 1MHz AC sine wave signal and directly drives the LED to generate an alternating light signal, avalanche The diode converts the alternating light signal into a current signal input module, and the module converts the photocurrent into a voltage signal. The effect is as shown in Figure 2. Since the APD is an active drive, the driving voltage noise is easily amplified, so the signal-to-noise ratio of the output signal will decrease and the waveform noise will increase. But the response speed of the avalanche tube is beyond the reach of ordinary PD.
Photocell adapter board:
Module application: PD, PIN, APD, photocell, photoelectric tube with pigtail, can be adapted to most of our shop
Number photocell
Module weight: 5.9g
Module size: 22*22mm
Positioning hole size: 3mm
The adapter board provides schematic diagrams and PCB files.
Buyers need to weld by themselves according to their own usage, and the default delivery is empty board parts.
