PROBLEM TO BE SOLVED: To perform load modulation communication with only a small loss.SOLUTION: A communication circuit 400 transmits AC power from a power transmission circuit 100 to a power reception circuit 200 using a coil link. The power reception circuit 200 of the communication circuit 400 includes a rectification circuit 220 for converting the received AC power to rectification output which is DC power, a charge pump circuit 230 having a first current passage P1 and a second current passage P2 for keeping constant a voltage ratio of a first voltage V1 of the first current passage P1 to a second voltage V2 of the second current passage P2, and a switching circuit 240 for, according to a signal indicating the information to be transmitted from the power reception circuit 200 to the power transmission circuit 100, switching between a first input state in which the rectification output is input to the first current passage P1 and a second input state in which the rectification output is input to the second current passage P2. The communication circuit further includes a data reception circuit for acquiring the information on the signal based on a change in load resistance in the power transmission circuit 100 accompanying the switching between the first input state and the second input state.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2017,JPO&INPIT【課題】損失の少ない負荷変調通信を行うこと。【解決手段】 通信回路400は、コイルリンクを用いて交流電力を電力送信回路100から電力受信回路200へ伝送する。また、通信回路400の受信回路200は、受信する交流電力を、直流電力である整流出力に変換する整流回路220と、第1電流経路P1と、第2電流経路P2とを有し、第1電流経路P1の第1電圧V1と,第2電流経路P2の第2電圧V2と,の電圧比を一定に維持するチャージポンプ回路230と、電力受信回路200から電力送信回路100へ伝送すべき情報を示す信号に応じて、第1電流経路P1へ整流出力を入力させる第1入力状態と、第2電流経路P2へ整流出力を入力させる第2入力状態と、に切換えるスイッチング回路240と、を備え、更に、第1入力状態と第2入力状態との切換に伴う電力送信回路100での負荷抵抗の変化に基づいて、信号に関する情報を得るデータ受信回路を備える。【選択図】 図4
