Gallium arsenide voltage-controlled oscillator and oscillator delay cell
US6034570A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 14, 1999 |
| Grant date | Mar 7, 2000 |
| Priority date | — |
| Expiry date | Jan 14, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03L7/183
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A single-gate SCFL delay cell is disclosed for implementation in a common ring oscillator VCO. The delay cell has a differential input stage the output current from which is fixed by two resistors. The differential input stage drives a source follower output stage providing an output capable of driving the differential input of the next stage of the oscillator. The current sources typically used in the source follower output stage have been replaced by voltage-to-current converters. The voltage-to-current converters are comprised of two MESFET devices the gates of which are coupled to a differential control voltage. The source of each of the two devices is coupled to a current source the value of the two current sources being equal. The resistor couples the two sources together such that the voltage drop across the resistor governs how much current is conducted by each of the two devices. The drain of one of the devices is coupled to the supply while the drain of the other device is coupled to the source of the source follower output stage. Thus, the output current of the source follower will be dictated by the difference between the voltage drop across the resistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.