Output driver with DLL control of output driver strength
US6417705B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 16, 2000 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Aug 16, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/0816
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An output driver includes an adjustable main output stage and a control circuit with a digital delay locked loop (digital DLL) circuit and an adjustable scaled output stage. The main output stage and the scaled output stage are both configured to adjust their strengths in response to a control signal generated by the control circuit. The control circuit receives a clock signal and propagates a transition through the scaled output stage. The DLL circuit compares the propagation time through the scaled output stage with a reference signal (that is dependent on the clock signal frequency) and generates the control signal as a function of comparison. The main output stage, receiving the same control signal, adjusts its strength in a corresponding manner.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.