| 摘要 |
PROBLEM TO BE SOLVED: To provide a signal modulation circuit capable of generating a feedback signal to a delta sigma modulation part without increasing electric power consumption and reducing a switching speed at the time of generating the feedback signal.SOLUTION: A signal modulation circuit comprises: a subtractor 10 that calculates a difference between an input signal and a feedback signal; an integrator 12; a phase inversion circuit 14; a monovalent and three value waveform generation circuit 16; a driver circuit 18; and a pulse synthesis circuit 22 that generates the feedback signal that feedbacks a driving signal from the driver circuit 18 to the input signal. The pulse synthesis circuit 22 comprises: a first resistor and a second resistor which are serially connected to each other; and a capacitor and a voltage limit diode which are connected in parallel with the first resistor, and generates the feedback signal from a connection point of the first resistor, the second resistor, and the voltage limit diode.SELECTED DRAWING: Figure 1 |
