Apparatus and method for generating clock pulses having a stable duty ratio
US5202647A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 1992 |
| Grant date | Apr 13, 1993 |
| Priority date | — |
| Expiry date | Mar 11, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/03
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An apparatus for generating clock pulses comprises a Colpitts-type quartz crystal oscillator having an inverter composed of a C-MOS integrated circuit, and a quartz-crystal resonator connected with said inverter, and an amplifying circuit for amplifying the output of said quartz-crystal oscillator and delivering clock pulses as output. A first resistor is provided between the input terminal of the inverter and the quartz-crystal resonator, and the input terminal of the inverter is connected with the input terminal of the amplifying circuit. The amplifying circuit is for connection with a load composed of TTL circuits. This amplifying circuit includes a capacitor for suppressing a direct-current bias voltage from the output of the oscillator, an inverter composed of a C-MOS integrated circuit for providing the clock pulses as output, and a negative feedback circuit which utilizes negative feedback to the inverter as a direct-current bias voltage corresponding to the duty ratio of the clock pulses. This apparatus may further comprise a power supply for supplying operation voltage to the amplifying circuit which matches that of the load.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.