Precise and programmable duty cycle generator
US6593789B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 14, 2001 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Dec 14, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2005/00039
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A precise and programmable duty cycle generator which can produce a user definable duty cycle clock signal with precision. This circuit is comprised of a number of generally known circuit elements such as a digital to analog converter (DAC), low pass filter (LPF) and operational transconductance amplifier (OTA), as well as a unique voltage controlled duty cycle generator (VCDCG). The circuit has the ability to produce a user programmable duty cycle clock signal with precision over a broad range of operational frequencies. The VCDCG circuit is unique and employs a number of stages, each of which has a current starved inverter which is immediately followed by a conventional inverter to allow duty cycle corrections to be either additive or subtractive. The current starved inverters are controlled by a single voltage, which causes the current starved inverter's delay to degrade/improve on only one transition to effect a change in the duty cycle. For improved precision, a differential embodiment employs the same VCDCG.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.