A new bipolar op-amp IC synthesis approach

Bipolar op-amp IC modules with a simple circuit structure are difficult to design for a wide range of design specifications, due to strong correlations between transistor parameters. As a result, bipolar op-amps are commonly designed resorting to complicated circuit structures which result in large chip area and high fabrication cost. We have developed a new synthesis approach which can generate bipolar op-amp IC modules for a wide range of design specifications with a simple structure. The approach incorporates two new methods which we have developed to predict Miller capacitance and to calculate transistor transconductance during transistor sizing. Differing from conventional methods, our methods consider the effect of device parasitics during the synthesis and hence are accurate. The approach has been implemented in our bipolar op-amp IC synthesis package.