THE TRUE POTENTIAL OF BiCMOS TECHNOLOGY FOR ANALOG IC DESIGN

M. Ismail

Ohio State University, USA

This course will introduce the audience to basic analog building blocks for
implementation in BiCMOS technology. These blocks include current mirrors, 
input stages, output stages, V-I converters, etc. The introduction of such 
blocks will follow a systematic approach that could eventually lead to the 
development of simple CAD tools to help, for example, identify transistors in an
all-MOS circuit which should be replaced by bipolar devices to achieve an 
optimum performance criterion. Furthermore a systematic design concept will be 
introduced and is based on connecting MOS and bipolar devices in such a way
that all internal nodes in the signal path have low impedance. This will help 
achieve excellent high frequency performance not achievable in MOS- or 
Bipolar-only designs. Finally, we will show that the cost of BiCMOS circuits
can be reduced significantly if a standard CMOS technology having an 
additional diffusion step to accommodate the base of a vertical npn is used.
Using such low cost BiCMOS technology with clever circuit design it is possible 
to achieve the same performance levels obtained from a full-fledged BiCMOS 
Process. Design examples at the system level, including an OTA-C IF Filter, A 
sigma-delta modulator, and a high frequency multiplier will be presented. These 
examples will show the true potential of BiCMOS technology for designing high 
performance analog circuits.

Course duration: 4 hours (half day).