To: Dave B who wrote (12619 ) 1/8/1999 1:35:00 AM From: Dave B Respond to of 93625
Uncle, Just to close out the patent question, I did a search on Rambus patents through the patent office web site, and the one in question sounded exactly like another patent they had already been granted. I've copied a little of each below to see that they already had the same basic technology patented. You'll also notice the filing dates. Definitely takes a while to get one of these through. Here's the original: United States Patent 5,736,892 Lee April 7, 1998 Differential charge pump circuit with high differential impedance and low common mode impedance Abstract A high gain, low voltage differential amplifier exhibiting extremely low common mode sensitivities includes a load element exhibiting a high differential resistance, but a low common mode resistance. The load element contains a positive differential load resistance and a negative differential load resistance, which offsets the positive differential load resistance. The output common mode level of the differential amplifier is one p-channel source to gate voltage drop below the power supply voltage prohibiting the common mode output voltage from drifting far from an active level. The differential amplifier also has application for use in a differential charge pump circuit. The high differential impedance of the differential amplifier allows the attainment of extremely small leakage, while a low common-mode impedance results in simplified biasing. Inventors: Lee; Thomas H. (Cupertino, CA) Assignee: Rambus, Inc. (Mountain View, CA) Appl. No.: 415602 Filed: April 3, 1995 And here's the one granted on 12/29/98: United States Patent RE36,013 Lee December 29, 1998 Differential charge pump circuit with high differential and low common mode impedance Abstract A high gain, low voltage differential amplifier exhibiting extremely low common mode sensitivities includes a load element exhibiting a high differential resistance, but a low common mode resistance. The load element contains a positive differential load resistance and a negative differential load resistance, which offsets the positive differential load resistance. The output common mode level of the differential amplifier is one p-channel source to gate voltage drop below the power supply voltage prohibiting the common mode output voltage from drifting far from an active level. The differential amplifier also has application for use in a differential charge pump circuit. The high differential impedance of the differential amplifier allows the attainment of extremely small leakage, while a low common-mode impedance results in simplified biasing. Inventors: Lee; Thomas H. (Cupertino, CA) Assignee: Rambus, Inc. (Mountain View, CA) Appl. No.: 870638 Filed: June 6, 1997