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Op-amp design: Bipolar or Cmos

J

Jim Thompson

Jan 1, 1970
0
Without saying too much to break my NDA with the fab, the target
voltage is 15V. So, no point in going more than 18V to 20V.

By the way, what's the best way to make 5 to 10pF capacitors?

Absolute best quality and pF/u^2 is MOM... metal-oxide-metal, but
poly-poly (poly-oxide-poly) are pretty good, when there is a thin
oxide step included in the process for capacitors.

Until I have time to ruminate, go ahead and talk to the folks at
Polarfab about their capabilities. Tell them I sent you ;-)

...Jim Thompson
 
J

Joerg

Jan 1, 1970
0
linnix said:
Without saying too much to break my NDA with the fab, the target
voltage is 15V. So, no point in going more than 18V to 20V.

18V would be a white-knuckle ride IMHO. 20V, maybe.
 
L

linnix

Jan 1, 1970
0
18V would be a white-knuckle ride IMHO. 20V, maybe.

OK, we will probably boost from 6V (batteries) to 24V and regulate it
down to 20V. The device is a second order closed loop system with
damping, using op amp integrations on MEMS. Any more descriptions
will need a 5 years NDA! After that, you can write a book if you
wish.
 
J

Joerg

Jan 1, 1970
0
linnix said:
OK, we will probably boost from 6V (batteries) to 24V and regulate it
down to 20V. The device is a second order closed loop system with
damping, using op amp integrations on MEMS. Any more descriptions
will need a 5 years NDA! After that, you can write a book if you
wish.

I just wouldn't do that on a 20V process. Bzzt ... poof ;-)
 
J

Jim Thompson

Jan 1, 1970
0
18V would be a white-knuckle ride IMHO. 20V, maybe.

OK, we will probably boost from 6V (batteries) to 24V and regulate it
down to 20V. The device is a second order closed loop system with
damping, using op amp integrations on MEMS. Any more descriptions
will need a 5 years NDA! After that, you can write a book if you
wish.

You need a custom circuit, NOT just an OpAmp.

...Jim Thompson
 
J

Joerg

Jan 1, 1970
0
Jim said:
OK, we will probably boost from 6V (batteries) to 24V and regulate it
down to 20V. The device is a second order closed loop system with
damping, using op amp integrations on MEMS. Any more descriptions
will need a 5 years NDA! After that, you can write a book if you
wish.


You need a custom circuit, NOT just an OpAmp.

Sure sounds like it. Opamps became all the rage when I got my degree.
Even back then anyone designing on the transistor level was considered
an old fart. So I started my career as an old fart and might as well
leave it as an old fart some day, although transistors are considered
more fashionable again, at least by the accountants.
 
L

linnix

Jan 1, 1970
0
OK, we will probably boost from 6V (batteries) to 24V and regulate it
down to 20V. The device is a second order closed loop system with
damping, using op amp integrations on MEMS. Any more descriptions
will need a 5 years NDA! After that, you can write a book if you
wish.

You need a custom circuit, NOT just an OpAmp.

Yes, I know. The op-amps are just the building blocks. Initially,
the op-amps will be wire-bonded out for external RCs adjustments. To
complicate things further, even our initially targeted MEMS process
might not meet the full spec; but we need to start somewhere.
 
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