Voltage-controlled variable duty-cycle oscillator
US6600379B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 21, 2001 |
| Grant date | Jul 29, 2003 |
| Priority date | — |
| Expiry date | Mar 5, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K7/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A voltage-controlled variable duty-cycle oscillator includes a current generator whose current Iref mirrored in three one-shots that each include two pair of series-coupled MOS transistors and a timing capacitor. The timing capacitor is precharged to Vcc in the first two one-shots, and to a lesser voltage Vcon in the third one-shot. The oscillator also includes pre and a post-NOR-gate logic. Output signals from the two one-shots are coupled to the pre NOR-gate logic to generate an intermediate oscillator signal whose duty cycle is determined by Iref and by the first two timing capacitors. The intermediate oscillator signal and output from the third one-shot are combined in the post NOR-gate logic to yield a VCO output signal whose duty cycle is determined by the ratio of the timing capacitor in the third one-shot compared to the sum of the timing capacitors in the first and second one-shots. VCO output signal duty cycle is a fairly linear function of Vcon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.