Transimpedance amplifier (TIA) is a current to voltage converter, it is useful for the requirement to convert the low-level current of a sensor to a voltage. The TIA can be used to amplify the current output of Photodiode, photo multiplier tubes/PMT, Avalanche photodiode/APD, laser power meter, conductivity, tunneling current/STM and other types of sensors to a usable voltage. In its simplest form a TIA has just a large valued feedback resistor, Rf. The gain of the amplifer is set by this resistor.
The performance, in terms of response or bandwidth, in terms of peaking or overshoot, and in terms of noise or SNR, is an extremely complicated, nonlinear, and highly interacting function of:
- the feedback resistor
- the source capacitance
- the desire bandwidth, gain factor and noise level /SNR
- the selection of op amp (Voltage/Current noise, input capacitance, GBP, offset)
- the selection of component
- the PCB design
Some useful information:
- Jerald Graeme, Photodiode Amplifiers—Op Amp Solutions
- Bob Pease, Waht’s all this transimpedance amplifer stuff, Anyhow
- Application Note from AD/Linear, TI, etc.
Here are two examples developed in our lab, to pushing the limits of performance for our home-built setup.
Example 1, Special TIA design for home-built high performance CE-C4D:
Example 2, Special TIA design for home-built high performance PHI:
Update time: 2021-11-20