Linear tuning circuit and tuning method thereof
AssigneeWinbond Electronics Corp.
InventorChih-Hao Lai
Life of this patent
Estimating the term…
Abstract
A linear tuning varactor circuit has the first single-end varactor circuit, the second single-end varactor circuit and a voltage divider. The first single-end varactor circuit has tuning terminal receiving the tuning voltage to change the capacitance thereof The second single-end varactor circuit has a reference voltage terminal receiving the reference with constant voltage. The first single-end varactor circuit and the second single-end varactor circuit are coupled to each other in series and have a node. The voltage divider is coupled to the tuning terminal, the reference voltage terminal and the node. The node has a divided voltage, which results from dividing a voltage difference between the tuning voltage and the reference voltage by the voltage divider with a pre-set voltage dividing ratio.
Claims4
A linear tuning varactor circuit, comprising:
- a plurality of single-end varactor circuits, each having a tuning terminal and a reference voltage terminal, the single-end varactor circuits coupled in series, a tuning terminal of a first single-end varactor circuit adapted to receive a tuning voltage for tuning a capacitance of the varactor circuit, a reference voltage terminal of a last single-end varactor circuit adapted to receive a reference voltage as a reference level;
- and
- a voltage divider, having a first terminal, a plurality of voltage dividing terminals and a second terminal, the first terminal coupled to the tuning terminal of the first single-end varactor circuit, the second terminal coupled to the reference voltage terminal of the last single-end varactor circuit, wherein the voltage dividing terminals of the voltage divider are coupled to nodes of the single-end varactor circuits, and each of the voltage dividing terminals has a divided voltage, which results from dividing a voltage difference between the tuning voltage and the reference voltage by the voltage divider with a pre-set voltage dividing ratio.
Dependencies are inferred from the claim text.