Dv/Dt Controlled Three-State Driver
Original Publication Date: 1985-Oct-01
Included in the Prior Art Database: 2005-Feb-19
An on-chip driver circuit is described which can deliver push-pull type AC performance while limiting output dv/dt to less than 1 volt/nsec without the use of a feedback capacitor. Standard push-pull drivers without some form of transition control circuitry will switch with worst-case dv/dt's well in excess of 1 volt/ nsec. Control of dv/dt is necessary in order to control di/dt which in turn will allow an increase in the simultaneous switching of circuits on the chip. The circuit shown is potentially faster than one employing capacitive feedback, requires less chip area, and contributes to better second level wiring ability by achieving a greater reduction in dv/dt. It operates as follows: When node B is allowed to rise, transistor T1 begins to conduct, thereby limiting the base drive available to transistors T2 and T3.