Hi,
Nice PCB
The horizontal cut placed above the front end decoupling caps. I like that move.
Only place for one single zener at each gate. I'd like the provision for two devices in series. Zener at gate, not preceding the gate resistor?
Provision for resistors in series with D1 and D2.
Do you have any RC RF-filter at the input?
All above can of course be patched in anyway ...
Nice PCB
The horizontal cut placed above the front end decoupling caps. I like that move.
Only place for one single zener at each gate. I'd like the provision for two devices in series. Zener at gate, not preceding the gate resistor?
Provision for resistors in series with D1 and D2.
Do you have any RC RF-filter at the input?
All above can of course be patched in anyway ...
Aha, I didn't think of dual zeners.
Thanks for the RC provision. RF filtering is mandatory in my world (a life long decease I got after EMC-studies).
Edit: What is your opinion about R in series with D1 and D2? Series R will smooth the charging pulses and damp out eventual diod ringing. And finally, reduction of pulse currents into front end ground plane.
I'm looking forward to the PCB's
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Aha, I didn't think of dual zeners.
Thanks for the RC provision. RF filtering is mandatory in my world (a life long decease I got after EMC-studies).
Edit: What is your opinion about R in series with D1 and D2? Series R will smooth the charging pulses and damp out eventual diod ringing. And finally, reduction of pulse currents into front end ground plane.
I'm looking forward to the PCB's
I just read your PM though I would reply to this here instead.
The LME pulls a constant current and so there are no high current transients due to the FETs having such a high input impedance. So a constant 10mA or so will flow into the cap and out of it hence also a constant current through the diode so there won't be any other noise from it.
I have separated the GND planes and added a 1206 pad linking them so you have the option of what you put there whether it be a 0R link, low value R or a choke or something.
I believe one can always have an input serial cap directly at the input terminal...
Also what is your opinion on the sink/source tracks followin close parallel to the power tracks? Same with the feedback? Is it OK?
Sink and source can follow each other really close together as long as possible and separate just before the output transistors... IMHO
Edit:
Could the chips reservoir caps be on the bottom side of the chip? Maybe better to trace the power tracks to the chip from that side and get rid of all possible interference between those and the sensitive stages of the pcb???
Also makes the sinc/source and feedback shorter - which should be nice?
Then keep signal input on the left side and power caps on the right...
IMHO...
Also what is your opinion on the sink/source tracks followin close parallel to the power tracks? Same with the feedback? Is it OK?
Sink and source can follow each other really close together as long as possible and separate just before the output transistors... IMHO
Edit:
Could the chips reservoir caps be on the bottom side of the chip? Maybe better to trace the power tracks to the chip from that side and get rid of all possible interference between those and the sensitive stages of the pcb???
Also makes the sinc/source and feedback shorter - which should be nice?
Then keep signal input on the left side and power caps on the right...
IMHO...
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Hi Boscoe & others,
I ? in your design and mine for that matter, if the zobel ground return path should be a separate wire back to common point ground?
I looked at OPC's original "wire" design & he had no zobel network on the pcb, so if used, it would have probably been at the speaker connector and possibly share the speaker return to the common point ground, which I assume is fine.
Rick
I ? in your design and mine for that matter, if the zobel ground return path should be a separate wire back to common point ground?
I looked at OPC's original "wire" design & he had no zobel network on the pcb, so if used, it would have probably been at the speaker connector and possibly share the speaker return to the common point ground, which I assume is fine.
Rick
The boards were sent off yesterday so it's too late to correct anything now.
I haven't been using any caps in those positions for the several boards I have made before and had minimal offset.
There's no point in running the sink/source traces together, have a look at the internal block diagram.
There will be very minimal crosstalk between these, also, the current drawn by the LME is constant.
The feedback path is tiny as they go it's about 40mm.
I haven't been using any caps in those positions for the several boards I have made before and had minimal offset.
There's no point in running the sink/source traces together, have a look at the internal block diagram.
There will be very minimal crosstalk between these, also, the current drawn by the LME is constant.
The feedback path is tiny as they go it's about 40mm.
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