Transimpedance amplifier

Home  ⇒  Overview Courses   ⇒  ElectronicsOperational amplifier ⇒ Transimpedance amplifier

Transimpedance amplifier

The following circuit, which is referred to as a current-voltage converter or transimpedance converter (TIA), converts an input current IIN into a defined output voltage VOUT:

Transimpedance amplifier

Transimpedance amplifier

The basis of the current-voltage converter is the inverting amplifier. Since the input current of the OP-Amp is negligibly small, we derive from the node rule:

IIN = - If

Applying the law of Ohm:

VOUT = Vf = If × Rf = - IIN × R

This makes it clear that the output voltage is proportional to the input current. The ratio of input current to output voltage is determined by the resistance Rf.


Exercise Op-Amp as Transimpedance Amplifier

Below you can see an Op-Amp circuit that converts a sensor signal of 4 ... 20 mA into a voltage signal of 0 to 10 V.

Op-Amp as Transimpedance amplifier - exercise

Op-Amp as Transimpedance amplifier - exercise

  1. What tasks do these two Op-Amp´s have in this circuit?
  2. What advantage does a sensor with a current signal of 4 to 20 mA offer compared to a sensor with a voltage signal of 0 to 10 V?
  3. In the diagram below, add the characteristic curve V1 depending on the sensor signal!
Op-Amp as Transimpedance amplifier - diagrams

Op-Amp as Transimpedance amplifier - diagrams

 

Ads Blocker Image Powered by Code Help Pro

Ads Blocker Detected!!!

We have detected that you are using extensions to block ads. Please support us by disabling these ads blocker.

Powered By
100% Free SEO Tools - Tool Kits PRO