LMH6401: When the input differential signal of LMH6401 is attenuated, the common-mode voltage will also attenuate simultaneously.

chaoqiang chen

Part Number: LMH6401

Lmh6401 was used in my design, Now during the simulation, I found that the common-mode voltage at the input end of P&N is being attenuated.

Now I have two questions:

1.Is my simulation result correct?

2.2. What is the block diagram of the input stage of LMH6401? Why is the common-mode voltage at the PN end being attenuated Description.pdf ?

1 个月前

0 Taylor 1 个月前

TI__Mastermind 45135 points

Hi,

We have received your post and the investigation will take some time. Thank you for your patience.

0 Taylor 1 个月前回复 Taylor

TI__Mastermind 45135 points

Hi,

Can you please share the tina file which you used for simulation?

0 chaoqiang chen 1 个月前回复 Taylor

Prodigy 80 points

LMH6401 Common.TSC this is my simulation

+1 Taylor 1 个月前回复 chaoqiang chen

TI__Mastermind 45135 points

Hi,

The input stage of the LMH6401 looks something like below:-

If VOCM is zero like in your case, the single ended input impedance will be 50ohm and hence you input common mode voltage will get attenuated by a factor of 5 (resistive divider formed by 200ohm (R4+R5 for INM) and 50hm internal to device).

0 chaoqiang chen 1 个月前回复 Taylor

Prodigy 80 points

Thanks

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LMH6401: When the input differential signal of LMH6401 is attenuated, the common-mode voltage will also attenuate simultaneously.