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公开(公告)号：JPH1022733A
公开(公告)日：1998-01-23
申请号：JP5979797
申请日：1997-02-26
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W
Abstract: PROBLEM TO BE SOLVED: To provide a method and device for switching a crystal via a bus while keeping one external pin for each one crystal design. SOLUTION: A multi crystal control oscillator 10 and its method is provided with a 1st crystal resonator 11, a 2nd crystal resonator 14, an oscillator circuit 23 and a switch 29. The switch 29 is connected between the 1st crystal resonator 11 and the oscillator circuit 23 and between the 2nd crystal resonator 14 and the oscillator circuit 23. The oscillator 10 is provided with a 1st pull down FET(field effect transistor) connected between the 1st crystal resonator 11 and an electric ground point 18 and a 2nd pull down FET connected between the 2nd crystal resonator 14 and the electric ground point 18.
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公开(公告)号：GB2227136A
公开(公告)日：1990-07-18
申请号：GB8926995
申请日：1989-11-29
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W
Abstract: A system for automatically tracking and locking to an applied scanning input signal the frequency of which may vary over a range of frequencies includes a PLL comprising a VCO and phase detector as well as a digital frequency counting section which forms a closed loop with the VCO. The VCO is operated preferably at 32 times the frequency of the applied input signal and provides a clock signal to the digital section which also receives the input signal. The digital section includes a counter and decoder-latch wherein the clock signal that is supplied to the counter is used to measure the frequency of the applied input signal. Counting and decoding result on alternating periods of the applied input signal such that the decoder-latch decides if the count is too low, too high or within the range of the PLL and controls the operating frequency of the VCO to find and maintain phase lock.
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公开(公告)号：DE3380511D1
公开(公告)日：1989-10-05
申请号：DE3380511
申请日：1983-05-02
Applicant: MOTOROLA INC
Inventor： NEWTON ANTHONY D , PERKINS GEOFFREY W
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4.发明专利
公开(公告)号：CA1204889A
公开(公告)日：1986-05-20
申请号：CA427137
申请日：1983-05-02
Applicant: MOTOROLA INC
Inventor： NEWTON ANTHONY D , PERKINS GEOFFREY W
Abstract: VIDEO DRIVER CIRCUIT AND METHOD FOR AUTOMATIC GRAY SCALE ADJUSTMENT AND ELIMINATION OF CONTRAST TRACKING ERRORS An apparatus and method for the automatic setup of a CRT operating point, or dc signal level (black), as well as the contrast, or gain level (gray), of a video display by sampling the CRT signal level of the individual cathodes and locking the dc signal level to a common dc setup reference and gain level to a value determined by a common contrast control signal and gain reference. An apparatus and method in which a common brightness control signal is modulated by a common contrast control signal such that a brightness control pedestal is added to each video signal path of a video display whereby picture black level does not change with contrast.
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公开(公告)号：HK56689A
公开(公告)日：1989-07-21
申请号：HK56689
申请日：1989-07-13
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W
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Patent Agency Ranking
公开(公告)号：GB2227136B
公开(公告)日：1992-10-28
申请号：GB8926995
申请日：1989-11-29
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W
Abstract: A system for automatically tracking and locking to an applied scanning input signal the frequency of which may vary over a range of frequencies includes a PLL comprising a VCO and phase detector as well as a digital frequency counting section which forms a closed loop with the VCO. The VCO is operated preferably at 32 times the frequency of the applied input signal and provides a clock signal to the digital section which also receives the input signal. The digital section includes a counter and decoder-latch wherein the clock signal that is supplied to the counter is used to measure the frequency of the applied input signal. Counting and decoding result on alternating periods of the applied input signal such that the decoder-latch decides if the count is too low, too high or within the range of the PLL and controls the operating frequency of the VCO to find and maintain phase lock.
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公开(公告)号：HK56589A
公开(公告)日：1989-07-21
申请号：HK56589
申请日：1989-07-13
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W , LUNN GERALD K
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公开(公告)号：DE3071937D1
公开(公告)日：1987-04-30
申请号：DE3071937
申请日：1980-10-14
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W
Abstract: A peak beam current leveler for use in a television receiver system which is responsive to the magnitude of the beam current supplied to the cathode of the cathode ray tube (CRT) exceeding a predetermined peak level to adjust the cathode peak beam current accordingly. The cathode beam current is supplied by a gain controlled video amplifier to the cathode through the base-emitter junction of a transistor. The collector electrode of the transistor is connected with a resistor for providing a voltage level proportional to the peak beam cathode current. A comparator circuit is utilized to provide a gain control signal that controls the gain of the gain controlled video amplifier such that the higher the beam current the more gain reduction that occurs. Thus, the level of the peak current is automatically reduced to maintain good focusing of the display on the CRT.
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公开(公告)号：EP0041554A4
公开(公告)日：1985-03-08
申请号：EP81900158
申请日：1980-10-14
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W
CPC classification number: H04N5/141
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公开(公告)号：EP0126097A4
公开(公告)日：1986-02-20
申请号：EP83903454
申请日：1983-09-30
Applicant: MOTOROLA INC
Inventor： PERKINS GEOFFREY W , LUNN GERALD K
CPC classification number: H04N5/10
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