[SOLVED] Normalized Gain and Input Common Mode Voltage range

[jovin555]

I would like to know what does Normalized Gain mean.I am going through LMH6554 and there are lot of graphs showing Frequency vs Normalized gain(page 7 on datasheet). The Normalized Gain is 0dB for different voltage gain.What does this actually means?

Also i would like to know what is input common mode voltage range.In LMH6554 datasheet, the value is +/-1.3V.What does this mean?

 

[KlausST]

Hi,

"Normalized" means that in the chart all graphs are shifted vertically to start at 0dB.
This makes them more compareable.
Indeed one line should start at 0dB (1V/V) and the other at 6dB (2V/V) and so on.
But then it is difficult to find out what's the overshot near cutoff frequency = passband flatness.

"Common mode input voltage"
In usual amplifying configuration both inputs have about the same voltage. Thisvoltage should be in the range of -1.3V ... +1.3V.
Don't make one or both inputs to be outside this range.

Klaus

 

[jovin555]

So what happens if a voltage above 1.3V or less than -1.3V is provided to the input?

 

[KlausST]

Hi,

So what happens if a voltage above 1.3V or less than -1.3V is provided to the input?

Maybe it does operate, but with additional errors
Maybe it refuses operation totally, for the time of overdriven input.
Maybe it dies.

Klaus

 

[FvM]

Maybe it dies.

Not before exceeding maximum ratings.