Invention Grant
- Patent Title: Automatic gain control circuit
- Patent Title (中): 自动增益控制电路
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Application No.: US12293810Application Date: 2007-03-21
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Publication No.: US09225927B2Publication Date: 2015-12-29
- Inventor: Luca Lococo , Francois Pichon , Jan Van Sinderen
- Applicant: Luca Lococo , Francois Pichon , Jan Van Sinderen
- Applicant Address: NL Eindhoven
- Assignee: NXP, B.V.
- Current Assignee: NXP, B.V.
- Current Assignee Address: NL Eindhoven
- Priority: EP06300282 20060324
- International Application: PCT/IB2007/050996 WO 20070321
- International Announcement: WO2007/110816 WO 20071004
- Main IPC: H04N5/44
- IPC: H04N5/44 ; H04N5/52 ; H03G3/00

Abstract:
An automatic gain control (AGC) circuit based on a cascade of a step automatic gain control unit and a second automatic gain control unit connected to adjust their gain in a synchronized manner to result in a combined impulsive gain variation. Hereby it is possible, e.g. to use a step automatic gain control unit instead of a continuous automatic gain control unit in an RF part of a TV tuner without resulting in visual artifacts—this applies both for digital and analog TV tuners. According to a preferred embodiment, the synchronization between the two automatic gain control units may be achieved by the first automatic gain control unit generating a control signal upon gain adjustment, this control signal serving to speed up a loop bandwidth controlling gain change of the second automatic gain control unit. In another embodiment, the control signal generated by the first automatic gain control unit is used to control a gain step of the second automatic gain control unit. In addition, the invention provides a tuner with an automatic gain control unit as mentioned, and a device, e.g. a TV or a hard disc recorder with such tuner.
Public/Granted literature
- US20100231801A1 AUTOMATIC GAIN CONTROL CIRCUIT Public/Granted day:2010-09-16
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