163results about How to "Increase the oscillation frequency" patented technology

A voltage controlled oscillator (VCO) includes a voltage controlled current source (VCCS), a negative resistance circuit (NRC), a first transformer, a second transformer, a first transistor and a second transistor. A current terminal of the VCCS receives a control voltage. First terminals of first and second current paths in the NRC are coupled to a current terminal of the VCCS. Primary sides of the first and the second transformers are respectively coupled to second terminals of the first and the second current paths. Secondary sides of the first and the second transformers are first and second output terminals of the VCO, respectively. First terminals of the first and the second transistor are respectively coupled to the secondary sides of the first and the second transformers. Control terminals of the first and the second transformers are respectively coupled to the primary sides of the first and the second transformers.

In a crystal oscillator having a crystal blank, and an IC chip having integrated therein an oscillation circuit, the crystal blank has a first excitation electrode disposed on its first principal surface, and an extension electrode extended from the first excitation electrode to a peripheral region of the crystal blank, and folded back to the second principal surface. A first and a second crystal connection terminal are disposed on a first principal surface of the IC chip, and the second crystal connection terminal extends to a central region on the first principal surface of the IC chip to constitute a second excitation electrode. The extension electrode is secured to the first crystal connection terminal through a bump, such that the second principal surface of the crystal blank opposes the first principal surface of the IC chip, thereby holding the crystal blank in parallel with the first principal surface of the IC chip. The crystal blank is excited by the first and the second excitation electrodes.

The invention discloses a phase-locked acceleration circuit based on level width extraction and a phase-locked loop system. The phase-locked acceleration circuit comprises a level extraction control circuit and a current injection switch module. The control output end of the level extraction control circuit is connected with the current injection control end of the current injection switch module;meanwhile, a current stepping control end of the current injection switch module and a driving input end of the level extraction control circuit are connected to a preset control signal output end ofthe phase frequency detector, which is used for controlling the current injection switch module to inject charges according to the level width change condition of the output signal of the preset control signal output end until the phase of the reference clock signal input by the phase frequency detector is synchronous with the phase of the feedback clock signal. The low-pass filter receives charges injected by the current injection switch module under the control on-off action of the phase-locked accelerating circuit, the charges are rapidly injected into the low-pass filter until the chargesare close to be stable, meanwhile, oscillation can be avoided through stepping charge injection, and the phase-locked time is shortened.