Impedance compensation in a buffer circuit
US8159262B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Feb 18, 2011 |
| Grant date | Apr 17, 2012 |
| Priority date | — |
| Expiry date | Feb 18, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K19/00384
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A compensation circuit for controlling a variation in output impedance of at least one buffer circuit includes a monitor circuit having a pull-up portion comprising at least one PMOS transistor and a pull-down portion comprising at least one NMOS transistor. The monitor circuit is configured to track an operation of an output stage in the buffer circuit and is operative to generate a first control signal indicating a status of at least one characteristic of corresponding pull-up and pull-down portions in the output stage over variations in PVT conditions to which the buffer circuit may be subjected. The compensation circuit further includes a control circuit generating first and second sets of digital control bits for compensating the pull-up and pull-down portions in the output stage over prescribed variations in PVT conditions. The second set of digital control bits is generated based at least on the first set of digital control bits and the first control signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.