Electrically controllable oscillator circuit, and electrically controllable filter arrangement comprising said circuits
US5117205A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 12, 1991 |
| Grant date | May 26, 1992 |
| Priority date | — |
| Expiry date | Apr 12, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B2201/02
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electrically controllable oscillator circuit (30) comprises two balanced transconductance circuits (G1, G2), each including transistor pairs arranged as inverters (Inv14) and as resistors (Inv5-6). The oscillation frequency (f) and the quality factor (Q) of the oscillator circuit (30) are controlled by means of a single control signal provided by a combined control circuit (Inv7, Dif, IM1, IM2). The current mirror circuit (IM1, IM2) and a differential pair (Dif) derived the control signal for adjusting the quality factor (Q) from a resistor-connected further transistor pair (Inv7) connected to the control signal for adjusting the frequency (f). The quality factor of an electrically controllable filter arangement including similar transconductance circuits (G-3-9) is adjusted by means of the control signal generated by the control circuit via a buffer circuit (B) and a low-pass circuit (C3).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.