Stable Logarithminc Amplifier

[Analog_man]

Hi,
I need a design description document or white paper regarding logarithmic Amplifer.
My application need to be able to work with couple of hundred volts also very accurate over temperature.

Thanks,

 

[FvM]

Logarithmitic amplifier may designate very different circuits, basic parameters as bandwidth, dynamic range and required accuracy should be given to clarify which flavour is meant.

 

[spark68]

To identify the right Logarithmic amplifier we need to have a better understanding of the application, like: Bandwidth, Dynamic Range in dB, operation Voltage range.
Logarithmic Amplifier are not very accurate if you have variable temperatures, these is a nice article that tries to improve the accuracy of Logarithmic Amplifier below:

**broken link removed**

You also may Google search for more possible info.

 

[FvM]

Logarithmic Amplifier are not very accurate if you have variable temperatures, these is a nice article that tries to improve the accuracy of Logarithmic Amplifier

Temperature compensation as presented in the article is used since decades in any commercial logarithmic amplifier (see e.g the TI, former Burr Brown LOGxxx IC) and can be found in example circuits for discrete log amps with differential pairs as well. They achieve a considerable accuracy, in so far I would contradict the above statement. It's not clear however, if this kind of analog computional circuit or a logarithmic IF detector (as used in a spectrum analyzer or a Radar) is requested.