I have experience with digital IC design. What should I study to design mixed-signal circuits? What books should I get? Is the transition a difficult one?
Re: Looking to get into mixed-signal IC design (analog-digit
Your question is not clear.
Whether you want to design mixed-signal project integratin some analog block those were designed by analog designer. In this case you need to study tools.
Or you want to design both analog and digital block by youself. In this case you need to study device physics and than analog circuitry itsels. After that you can start mixed signal design.