CR oscillation circuit
AssigneeSeiko Epson Corporation
InventorAkira Shirao
Life of this patent
Estimating the term…
Abstract
A CR oscillation circuit includes inverters forming a loop for circulation of a signal, CR time constant circuits inserted into the loop for delaying the signal, each circuit having a capacitor, a plurality of resistance elements, and a transmission gate that selects an arbitrary resistance element of the plurality of resistance elements as a charge and discharge path of the capacitor, and a gate voltage generation circuit as means for outputting a gate voltage for controlling ON/OFF of each transmission gate that outputs a constant voltage in conjunction of a threshold voltage of a field-effect transistor as a gate voltage for turning ON the transmission gate.
Claims9
A CR oscillation circuit comprising:
- at least one switching gate forming a loop for circulation of a signal;
- a CR time constant circuit inserted into the loop for delaying the signal, the circuit having a capacitor, a plurality of resistance elements, and a selection part that selects an arbitrary resistance element of the plurality of resistance elements as a charge and discharge path of the capacitor;
- and
- a control section that controls ON/OFF of the selection part and controls the selection part so that temperature characteristics of a resistance value of the selection part may be constant when the selection part is turned ON,
- the selection part including a transmission gate, and
- the control section having a gate voltage generation unit that outputs a gate voltage for controlling ON/OFF of the transmission gate and outputs a constant voltage in conjunction with a threshold voltage of a field-effect transistor as a gate voltage for turning ON the transmission gate.
Dependencies are inferred from the claim text.