[sdiy] LM3900 Sub ( more info then you'd ever wanted! )

[Gene Stopp]

Newly graduated engineer's first layout?
First cut rushed into production?
Experiment turned into product?
Grumpy employee making a statement?
Chip designed on January 2nd?

- Gene (never worked for a chip company, but in hi-tech for 26 years)



-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Phil Harbison
Sent: Tuesday, January 04, 2005 5:35 PM
To: synth-diy at dropmix.xs4all.nl
Subject: Re: [sdiy] LM3900 Sub ( more info then you'd ever wanted! )


Scott Gravenhorst wrote:

> In one of those email exchanges discussing the LM3900, someone else also
> pointed out, and I just looked to confirm that the pinout is one of the
> stupidest for a 4 amplifier package ever.

That is indeed a strange layout. Perhaps the designer thought
it would be useful to tie the (+) inputs of two amps together
and therefore made those pins adjacent. I cannot think of any
other rationale for this layout.