US 5,517,158 AGranted

Self-timed oscillator circuit including starting and stopping circuitry

AssigneeAT&T Corp.

InventorThaddeus J. Gabara

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Abstract

A relatively simple low-power-dissipation oscillator circuit comprises an inductor in series with a capacitor. Self-timing circuitry connected to an output node point between the inductor and the capacitor compensates for resistive losses in the circuit and thereby insures generation of a constant-amplitude output sine wave suitable for driving PPS CMOS circuitry. The oscillator circuit also includes starting and stopping circuitry connected to the inductor. To conserve power during so-called data inactive periods, the oscillator circuit can be abruptly stopped in a manner that preserves stored states in the CMOS circuitry and provides an output voltage suitable for powering conventional (non-PPS) CMOS circuitry while establishing a reliable basis for subsequently reinitiating oscillations.

Claims8

Dependent claims

An oscillator circuit comprising

an inductor having first and second terminals,
a capacitor having first and second terminals,
means adapted to connect said first inductor terminal to a first direct-current power source,
an output node point,
means connecting said second inductor terminal to said output node point,
means connecting said output node point to said first capacitor terminal,
means adapted to connect said second capacitor terminal to a point of reference potential,
said inductor and said capacitor constituting a series-resonant oscillatory path designed to oscillate at a specified frequency to provide a sine wave at said output node point,
and self-timing means connected to said output node point and responsive to each positive-going excursion of said sine wave for supplying energy to compensate for resistive losses in said path thereby to insure that each positive-going excursion of the sine wave extends to a prespecified maximum value and responsive to each negative-going excursion of said sine wave for supplying energy to compensate for resistive losses in said path thereby to insure that each negative-going excursion of the sine wave extends to a prespecified minimum value,
further including starting means connected to said output node point for initially and momemtarily applying to said node point a second direct-current power source whose voltage has a value that differs from that provided by said first source, thereby to initiate oscillations in said path.

7 more elements

An oscillator circuit comprising

an inductor having first and second terminals,
a capacitor having first and second terminals,
means adapted to connect said first inductor terminal to a first direct-current power source,
an output node point,
means connecting said second inductor terminal to said output node point,
means connecting said output node point to said first capacitor terminal,
means adapted to connect said second capacitor terminal to a point of reference potential,
said inductor and said capacitor constituting a series-resonant oscillatory path designed to oscillate at a specified frequency to provide a sine wave at said output node point
and self-timing means connected to said output node point and responsive to each positive-going excursion of said sine wave for supplying energy to compensate for resistive losses in said path thereby to insure that each positive-going excursion of the sine wave extends to a prespecified maximum value and responsive to each negative-going excursion of said sine wave for supplying energy to compensate for resistive losses in said path thereby to insure that each negative-going excursion of the sine wave extends to a prespecified minimum value,
wherein said self-timing means comprises
an inverter having input and output terminals,
a p-channel MOS transistor device having gate, source and drain electrodes,
an n-channel MOS transistor device having gate, source and drain electrodes,
means directly connecting together the drain electrodes of said p-channel and n-channel devices,
means directly connecting together the gate electrodes of said p-channel and n-channel devices,
means connecting the output terminal of said inverter to said connected-together gate electrodes,
means connecting the input terminal of said inverter to said connected-together drain electrodes and to said output node point,
means adapted to connect the source electrode of said p-channel device to a direct-current power source whose output voltage has a value that exceeds that provided by said first source,
and means adapted to connect the source electrode of said n-channel device to a point of reference potential.

16 more elements

Dependencies are inferred from the claim text.