Dynamic Output Control (DOC) Circuitry Technology And Applications (Rev. B)

Texas Instruments (TI[TM]) next-generation logic is called the Advanced Very-low-voltage CMOS (AVC) family. The AVC family features TI?s Dynamic Output Control (DOC[TM]) circuit (patent pending). DOC circuitry automatically lowers the output impedance of the circuit at the beginning of a signal transition, providing enough current to achieve high signaling speeds, then subsequently raises the impedance to limit the overshoot and undershoot noise inherent in high-speed, high-current devices. This allows a single device to have characteristics similar to both series-damping-resistor outputs during static conditions and to high-current outputs during dynamic conditions, eliminating the need for series damping resistors. Due to the characteristics of the DOC output, the dc drive-current specifications for DOC devices are not useable as a relative indicator of the dynamic performance. A thorough understanding of static and dynamic drive-current conditions is required to design with the DOC feature of AVC logic.