im making a PCBs for a bridged/parallel dual LM4780 setup. Class project. question is, can the NC pins on the LM4780 be in contact with GND? it makes routing the power to the chip much easier if this isnt an issue.
thanks for your time.
rmr
thanks for your time.
rmr
Hi!🙂
Have a look at this page:
http://home.pacific.net.au/~gnb/audio/lm4780.html
I think this answers your question.
Regards
Tor Martin
Have a look at this page:
http://home.pacific.net.au/~gnb/audio/lm4780.html
I think this answers your question.
Regards
Tor Martin
"LM4780 is a dual LM3886
The LM4780 package contains two LMP3886AT silicon dice. This is the same die as used in the LM3886.
LM3886 design procedure and schematics may be applied to the LM4780, with a slight derating of 0.5 dB in the nominal output power, from 68 Watts down to 60 Watts per channel."
heh, that helps alot. the schematic i used to design the PCB is from a national semiconductor bridged/parallel LM3886 application notes pdf. kinda saves a bit of worrying if the schhematic would be compatible.
i was going to cut the NC pins like suggested on another thread, but the idea kinda bothered me.
thanks alot =D
The LM4780 package contains two LMP3886AT silicon dice. This is the same die as used in the LM3886.
LM3886 design procedure and schematics may be applied to the LM4780, with a slight derating of 0.5 dB in the nominal output power, from 68 Watts down to 60 Watts per channel."
heh, that helps alot. the schematic i used to design the PCB is from a national semiconductor bridged/parallel LM3886 application notes pdf. kinda saves a bit of worrying if the schhematic would be compatible.
i was going to cut the NC pins like suggested on another thread, but the idea kinda bothered me.
thanks alot =D
Perhaps you should have read ALL the way through the referenced URL to the answer to your question:
The "NC" pins are truely "No Connection"
Pins 1, 3, 6, 13, 23, 24 and 26 are designated as "NC" or "No Connection". In existing published designs and the reference design in the National Semiconductor data sheet, these pins are variously connected to V+, GND and nothing. There is actually no particular electronic design requirement for them to be connected to anything at all, as the pins are independently mounted in the insulated packaging and have no internal connection.
They may be safely connected to any other pin or left unconnected.
As a design aid, they can be connected to adjacent pins to make PCB tracks wider for the power supply rails, or used as a "via" to carry PCB tracks from one row of pins through the second row of pins to other components.
The "NC" pins are truely "No Connection"
Pins 1, 3, 6, 13, 23, 24 and 26 are designated as "NC" or "No Connection". In existing published designs and the reference design in the National Semiconductor data sheet, these pins are variously connected to V+, GND and nothing. There is actually no particular electronic design requirement for them to be connected to anything at all, as the pins are independently mounted in the insulated packaging and have no internal connection.
They may be safely connected to any other pin or left unconnected.
As a design aid, they can be connected to adjacent pins to make PCB tracks wider for the power supply rails, or used as a "via" to carry PCB tracks from one row of pins through the second row of pins to other components.
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