PCB Audio AMP current draw???

[John_Smith]

Hi all! As much as the "How many amps does my PCB draw in the 5v rail" question has been posed any number of times on these boards, I want to know if some tech extraordinaire can measure the current draw for the audio amp's on some of the thirstier board sets around. Not sure which ones would have the most current hungry amps, but if someone can help out on this that would be great!!

A lot of PCB owners manuals will report a required 1Ah on the 12volt rail (-5v rail too for that matter) but assumedly there's a bit of included head room here. Anyone have the equipment to measure the audio hardware current draw on a range of PCB's????

Cheers!

 

[ttooddddyy]

It will vary of course depending on how it is driven.

To get get a "ball park" figure, check out the data sheet of the audio output IC, take the HA13001 as used in MVS for example.

in stereo mode 2 x 5.5 W (rms) = 11 Watts

current = 11/12 = 0.92 amps.


Edit:This does assume the output stage is designed for max efficiency into the given load (why would you design it any other way) also heat dissipation needs to be taken into account.

 

[John_Smith]

LOL dude that didn't take ya long Toddy!! I had a funny feeling you'd jump aboard this thread with some insightful tid-bits!

Thanks man, that's really helpful.

 

[ttooddddyy]

Its interesting that with the HA13001 in mono mode (17 W BTL) it is 1.46 amps.

One would be forgiven for thinking the mono config would result in less max current draw, but thats not the case