Bipolar IC Voltage Extender
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Bipolar integrated circuits (ICs) require bias voltages on certain diffusions to properly isolate the circuit components from each other. Typically, the most negative voltage applied to the bipolar IC is connected to the P-type substrate. Therefore, all N-type devices diffused into the substrate (Fig. 1) are necessarily at an equal or higher voltage, which provides the necessary isolation for the individual transistors. Resistors are isolated in a similar fashion. This arrangement, however, has a limit on how large the voltage difference may be across this P-N junction. This limit is called the EPI to isolation breakdown voltage. Heretofore, this EPI to isolation voltage limit was used as a limit to the difference between the most positive and the most negative voltage a bipolar integrated circuit might use, i.e.