TTL COMPATIBLE INPUT FOR BIMOS CIRCUITS
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2001-Oct-15
It is often desired to develop the input threshold voltage of Transistor-Transistor-Logic (TTL) of two bass-emitter voltages (V,,) on technologies other than TTL. Some technologies such as Power SIMOS which combine bipolar and MOS devices do not allow the bipolar devices to be referenced to ground, thereby making it difficult to achieve the TTL input voltage. This restriction is the result of a P type substrate serving as the output of the circuit, thereby limiting all epitaxial regions (PNP bases and NPN collectors) to a voltage level at or near the positive supply voltage.