ECL: Why'd they use negative voltages?

Demasiados Dolares :-)

But seriously, what would be the problem driving the two subwoofers 180 degrees out of phase and reverse the connections for one of them? To the end customer it'll be the same tchk tchk *BOOM* sound.

In the rare case of music that is highly asymmetrical down there a simple limiter could kick in. So far I've not encountered H-bridges in lower-end class-D amps but then again I don't deal with audio much, I typically re-purpose this stuff.

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I was the young buck, right out of school, joined Motorola, working for Narud, at the very beginnings of MECL. I forgot Norm Miller and Art Capon in my list above. ...Jim Thompson

The subwoofer is usually only one. As for the channel pairs, yes, you are right, they are often made out of phase. The only problem with that is getting it wired properly in the different configurations.

H-bridge outputs are typical for the low end single IC solutions.

Vladimir Vassilevsky DSP and Mixed Signal Design Consultant

I meant the really low-cost chips such as this one, the things you find in TV sets, boom boxes and other consumer gear:

Dave Berning used that at some point.

Tim

Joel Koltner schrieb:

Hello,

I saw a design using ECL and TTL logic together. For easier interface between ECL and TTL they used +5,2 and 0 V for ECL ICs. Only very few ECL logic was used.

Bye

There used to be a translator chip, ECL (on -5.2V) to TTL (on +5V)... really easy to do if you do it all with currents.

My MC4024 "TTL" Multivibrator actually has an ECL current-mode cross-coupled oscillator that is level-shifted to TTL. Some data sheets still show the schematic (see my website for a schematic from a