LMH6882 shutdown behaviour

Guenther Klenner1

Other Parts Discussed in Thread: LMH6882, LMH6881

Hi,
We like to use LMH6882 as baseband amplifier. We need to split and combine various signal paths. LMH6882's datsheet does not describe input, output and coupling performance on shutdown. Is some description available?

Is the Tina-Spice Model valid for this case?

Regards
Guenther

over 10 years ago

0 Loren Siebert 1 over 10 years ago

TI__Genius 13935 points

Hello Guenther,

The TINA model does not model shutdown behavior. I will have to look into this, I don't have the data available.

Regards,

Loren

0 Loren Siebert 1 over 10 years ago in reply to Loren Siebert 1

TI__Genius 13935 points

Hello Guenther,

Because the LMH6881 and LMH6882 use differential amplifier stages with feedback, there are always feedback resistors connected to the inputs and outputs.

I measured more than -60dBc of input to output isolation when the part is disabled, but because of the feedback network there is not a high impedance state when the part is disabled. This is around 400 Ohms differential with an unknown common mode component. I don't think that the LMH688x parts will work well in a MUX configuration.

Regards,

Loren

0 Guenther Klenner1 over 10 years ago in reply to Loren Siebert 1

Prodigy 20 points

Hello Loren,
Thank you for the effort and detailed results. They are very useful for us. We'll do a testboard and keep you updated.

Regards
Guenther

Amplifiers

Amplifiers forum

LMH6882 shutdown behaviour