To CMOS or Not

[West]

I know the main advantages of using CMOS ICs are to reduce power supply
requirements and to provide a higher noise immunity.
What I don't know is when CMOS ICs are not called for. What are the
advantages of non-CMOS chips? Thank you.

west

 

[Jim Thompson]

I know the main advantages of using CMOS ICs are to reduce power supply
requirements and to provide a higher noise immunity.
What I don't know is when CMOS ICs are not called for. What are the
advantages of non-CMOS chips? Thank you.

west

Bipolar: Low noise amplification, high bandwidth, low offsets,
precision...

But the best of both worlds is BiCMOS.

...Jim Thompson

 

[John Larkin]

I know the main advantages of using CMOS ICs are to reduce power supply
requirements and to provide a higher noise immunity.
What I don't know is when CMOS ICs are not called for. What are the
advantages of non-CMOS chips? Thank you.

west

Bipolar ECL, or better yet SiGe, when you want to go faster. See the
OnSemi Eclips Lite and GigaComm parts, or the Analog Devices
comparators. 40 ps edges! TI has a 5 GHz opamp, maybe SiGe.

InGaAs when you want to go really fast. Hittite and W-J and such.

Bipolar for high voltage swings, too, like voltage regulators.

John

 

[Tim Williams]

Bipolar for high voltage swings, too, like voltage regulators.

Er, second breakdown? MOSFETs..!?

Tim

 

[John Larkin]

Er, second breakdown? MOSFETs..!?

Tim

There aren't a lot of high-voltage cmos processes. Supertex has some
display drivers. AT&T used to have a 350 volt linear cmos process
(Apex used it) but I think it's gone.

There are those IR high-side mosfet drivers; I'm not sure how they
work inside.

John

 

[JosephKK]

John Larkin [email protected] posted to
sci.electronics.design:

Bipolar ECL, or better yet SiGe, when you want to go faster. See the
OnSemi Eclips Lite and GigaComm parts, or the Analog Devices
comparators. 40 ps edges! TI has a 5 GHz opamp, maybe SiGe.

InGaAs when you want to go really fast. Hittite and W-J and such.

Bipolar for high voltage swings, too, like voltage regulators.

John

There are also some special functions like log amps, and multipliers
that may not have a reasonable CMOS substitute.