摘要 |
A linear channel select filter having a simple structure is used for an IF selector of a satellite broadcasting tuner, linearly changes a desired frequency by adjusting an output current, and includes a GM current cell unit determining a control voltage according to a select signal, generating an output current according to an differential input voltage, linearly controlling the output current according to the control voltage, and providing a linearly variable resistance according to the linearly controlled output current, and a capacitor circuit coupled to the GM cell unit to provide a capacitance to generate a cutoff frequency voltage according to the output current and the variable resistance. An occupying area and a size of the filter is reduced.
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