LMH0324: LMH0324+LMH0302 1 input 4 output SDI no output

boer.deng

Expert 1085 points

Part Number: LMH0324
Other Parts Discussed in Thread: LMH0302

LMH0324 configuration parameters are as follows

0x00=0x08

0x27=0x04

0x30=0xA3

0x31=0x63

0x32=0x00

0x33=0x00

over 5 years ago

0 Nasser Mohammadi over 5 years ago

TI__Guru* 88905 points

Hi Boer,

I reviewed your schematic and it looks fine. I am assuming you have LMH0324 data sheet. Please follow pcb layout guidelines.

Regards,,nasser

0 boer.deng over 5 years ago in reply to Nasser Mohammadi

Expert 1085 points

The layout diagram is as follows: the difference line is processed by 100 euros, and the SDI line is processed by 75 euros.

0 Nasser Mohammadi over 5 years ago in reply to boer.deng

TI__Guru* 88905 points

Hi Boer,
A couple of comments:
1). Please put R20 in parallel with R21 and move them to in between your 75-ohm traces. Move C19 next to them as well. Do the same for R11, R12, and C13. These outputs are differential and this way magnetically they are coupled to one another and you would get a better eye diagram.
2). To improve return loss, please void or no ground or VCC under passive components or pins that connect to either 75-ohm or 100-ohm controlled impedance.
Regards,,nasser

0 boer.deng over 5 years ago in reply to Nasser Mohammadi

Expert 1085 points

These reasons seem to be only a multi-distance impact, but not without waveform output?We have been mass producing LMH0302. LMH0302 should be ok

0 Nasser Mohammadi over 5 years ago in reply to boer.deng

TI__Guru* 88905 points

Hi Boer,
These recommendations were given to provide optimum eye opening. If you are happy with what you have, then you can disregard these. I am going to close this case and please re-open this case if there is a new update.
Regards,,nasser

Interface

Interface forum

LMH0324: LMH0324+LMH0302 1 input 4 output SDI no output