公开(公告)号：US10027280B1

公开(公告)日：2018-07-17

申请号：US15653519

申请日：2017-07-18

Applicant: Novatek Microelectronics Corp.

Inventor： Cheng-Dao Su ,  Chih-Hung Chen ,  Tzu-Cheng Yang ,  Yi-Ming Wu

IPC: H03K5/14 ,  H03B5/12 ,  H03K23/40 ,  H03K21/10 ,  H04B17/10

Abstract: An inductor-less local oscillator (LO) signal generation apparatus configured to generate one or more output signals which reduce a frequency pulling effect. The LO signal generation apparatus includes a multi-phase signal generation circuit, a phase signal generation circuit and one or more output circuits. The multi-phase signal generation circuit receives an input clock signal having a first frequency to generate a multi-phase clock signal. The multi-phase clock signal includes a plurality of clock signals each having the first frequency and different phases. The phase signal generation circuit is coupled to the multi-phase signal generation circuit to receive the multi-phase clock signal and output a plurality of phase signals indicating the phases of the clock signals. The one or more output circuits output the one or more output signals according to the clock signals and the phase signals without receiving feedback of any of the one or more output signals.

公开(公告)号：US11245358B1

公开(公告)日：2022-02-08

申请号：US17105454

申请日：2020-11-25

Applicant: NOVATEK Microelectronics Corp.

Inventor： Cheng-Dao Su ,  Tzu-Cheng Yang ,  Chih-Hung Chen

IPC: H03L1/00 ,  G05F3/26 ,  H03B5/04 ,  H03K3/011 ,  H03K3/013 ,  H03B5/12

Abstract: A voltage controlled oscillator is provided. The voltage controlled oscillator includes a current controlled oscillator, a voltage to current conversion circuit and a noise cancellation circuit. The current controlled oscillator is configured to receive a bias current and generate an oscillating signal with an oscillating frequency according to the bias current. The voltage to current conversion circuit is coupled to a power supply voltage and configured to generate a supply current according to an input voltage. The noise cancellation circuit is configured to receive a bias voltage and the supply current from the voltage to current conversion circuit, and configured to generate a noise cancellation current in response to power supply voltage variation and cancel the noise cancellation current from the supply current to generate the bias current. The bias voltage of the noise cancellation circuit is coupled to an internal voltage of the voltage to current conversion circuit.