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US 2006/0049880 A1Published application
Voltage controlled oscillator (vco) with output buffer
AssigneeInfineon Technologies AG
InventorsHans-Martin Rein, Hao Li
Life of this patent
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Abstract
An oscillator system is disclosed and includes an oscillator circuit having a differential output producing a differential output signal thereat having a frequency that is a function of an input voltage. The oscillator system further includes an output buffer coupled to the differential output of the oscillator circuit. The output buffer includes an inductive voltage divider circuit configured to weaken a loading at the oscillator differential output and it increases the output power.
Claims51
An oscillator system, comprising:
- an oscillator circuit comprising a differential output having a differential output signal thereat having a frequency that is a function of an input voltage;
- and
- an output buffer coupled to the differential output of the oscillator circuit, the output buffer comprising an inductive voltage divider circuit configured to weaken a loading at the oscillator differential output.
An oscillator system, comprising:
- an oscillating means operable to output a differential output signal having a frequency that is a function of an input voltage;
- and
- an output buffer means coupled to the oscillating means, and operable to decouple the oscillating means from an external load and to amplify signal amplitude, the output buffer means comprising a loading manipulation means operable to reduce a loading at an output of the oscillating means.
An oscillator system, comprising:
- an oscillator circuit comprising a differential output having a differential output signal thereat having a frequency that is a function of an input voltage;
- and
- an output buffer coupled to the differential output of the oscillator circuit, the output buffer comprising:
- an emitter follower circuit configured to provide a substantially high input impedance at an input thereof, and provide a substantially low output impedance at an output thereof;
- an emitter coupled pair circuit coupled to an output of the emitter follower circuit, wherein the emitter coupled pair circuit is configured to amplify the signal and further isolate the oscillator circuit from an external load;
- a base-grounded transistor circuit coupled to the emitter coupled pair circuit, wherein the cascode stage is configured to reduce a load resistance at an output of the emitter coupled pair circuit, thereby improving a speed thereof;
- and
- a bias current circuit coupled to the base-grounded transistor circuit, and configured to provide a DC bias current to keep transistors in the base-grounded transistor circuit from turning off when transistors in the emitter coupled pair circuit turn off, thereby improving a speed, linearity, and an output signal amplitude of the output buffer.
5 more elements
Dependencies are inferred from the claim text.