Semiconductor device and capacitance sensor circuit
AssigneeLAPIS Technology Co., Ltd.
InventorMasayuki Otsuka
Life of this patent
Estimating the term…
Abstract
A semiconductor device comprises a control unit, a semiconductor memory, a reference capacitance unit, a determination capacitance unit, a calibration circuit configured to supply a selection signal to the reference capacitance unit to selectively connect capacitors to differing potentials, and a determination circuit configured to charge a capacitance of the reference capacitance unit, to charge a capacitance of the determination capacitance unit, and to attain a comparison result by comparing the differing potentials. The control unit is configured to control rewriting of the semiconductor memory on the basis of a determination result of the determination circuit.
Claims9
A semiconductor device, comprising:
- a semiconductor memory constituted of a capacitance element;
- a control unit that is configured to control a rewrite voltage for the semiconductor memory;
- a reference capacitance unit including a plurality of capacitors, each of which has a reference capacitance, and each of which is connected between a first line and a line of a prescribed potential via a switch element;
- a determination capacitance unit, one end of which is connected to a second line and another end of which is grounded, the determination capacitance unit being constituted of a capacitance element having a same structure as the capacitance element constituting the semiconductor memory;
- a calibration circuit that is configured to supply, to the reference capacitance unit, a selection signal that is configured to selectively connect, on the basis of a signal level of the selection signal, any of the plurality of capacitors to between the first line and the line of the prescribed potential by controlling the switch element connected to each of the plurality of capacitors to be ON or OFF;
- and
- a determination circuit that is configured to charge a capacitance of the reference capacitance unit by transmitting a charge current to the first line, to charge a capacitance of the determination capacitance unit by transmitting a charge current to the second line, and to attain a comparison result by comparing a potential of the first line to a potential of the second line,
- wherein the control unit is configured to control rewriting of the semiconductor memory on the basis of a determination result of the determination circuit.
A capacitance sensor circuit that is formed on a same chip as a semiconductor memory constituted of a capacitance element, and that detects a capacitance of the capacitance element, the capacitance sensor circuit comprising:
- a reference capacitance unit including a plurality of capacitors, each of which has a reference capacitance, and each of which is connected between a first line and a line of a prescribed potential via a switch element;
- a determination capacitance unit, one end of which is connected to a second line and another end of which is grounded, the determination capacitance unit being constituted of a capacitance element having a same structure as the capacitance element constituting the semiconductor memory;
- a calibration circuit that is configured to supply, to the reference capacitance unit, a selection signal that is configured to selectively connect, on the basis of a signal level of the selection signal, any of the plurality of capacitors to between the first line and the line of the prescribed potential by controlling the switch element connected to each of the plurality of capacitors to be ON or OFF;
- and
- a determination circuit that is configured to charge a capacitance of the reference capacitance unit by transmitting a charge current to the first line, to charge a capacitance of the determination capacitance unit by transmitting a charge current to the second line, and to attain a comparison result by comparing a potential of the first line to a potential of the second line.
Dependencies are inferred from the claim text.