Patent ID: 6051995
Filing Date: 2000-04-18
Classification: H03K

Abstract:
A low noise CMOS circuit to provide a constant impedance load and linear ramped current waveforms at the circuit output in response to receiving an input signal at a circuit input, the circuit comprising:a first pair of driver transistors, including a first PMOS pullup and a first NMOS pulldown transistor, with the circuit output operatively connected to the drain of said first PMOS driver and the drain of said first NMOS driver;a second pair of driver transistors, including a second PMOS pullup and a second NMOS pulldown transistor, with the sources and drains of said PMOS pullup transistors operatively connected in parallel and the sources and drains of said NMOS pulldown transistors operatively connected in parallel;four pre-driver circuits of pullup and pulldown transistors, with the gates of each pre-driver circuit operatively connected to the CMOS circuit input, and with each said pre-driver circuit operatively connected to the gate of a corresponding driver transistor;a first source-follower NMOS pullup transistor, with the source operatively connected to the gate of said second PMOS driver, and the gate of said first source-follower pullup operatively connected to the gate of said first NMOS driver;a first source-follower PMOS pulldown transistor, with the source operatively connected to the gate of said second NMOS driver, and the gate of said first source-follower pulldown operatively connected to the gate of said first NMOS driver.