Abstract: A noncontact transmission device 100 is provided with a driver 106 for driving a coil 102; a system clock oscillator 110 for outputting a system clock; a monitoring clock oscillator 112 for outputting a monitoring clock LF0 having a frequency lower than that of the system clock CK0; and a control circuit 108. The control circuit 108 outputs a system clock oscillating control signal S60 based on the monitoring clock LF0 while being in a standby state and makes the system clock oscillator 110 intermittently output a system clock CK0 in synchronization with the control signal S60. In a period when the system clock CK0 is being outputted, the coil 102 is driven by a driver control signal SD and whether the device 200 to which data is to be transmitted is arranged or not is detected.

Abstract: A noncontact transmission device (100) is provided with a monitoring clock oscillator (112) for outputting a monitoring clock (LF0) having a frequency lower than that of a system clock (CK0); a control circuit (108); a memory (114) having information (D) stored to be used by the control circuit (108); and a reset circuit (116). The control circuit (108) includes an internal storage circuit for storing the information (D) read out from the memory (114). The control circuit (108) reads out and updates the information (D) stored in the internal storage circuit from the memory (114) with an update period based on the monitoring clock (LF0). Furthermore, the control circuit (108) is reset with a reset period longer than the update period based on the monitoring clock (LF0), and, each time the control circuit (108) is reset, reads out the information (D) from the memory (114) and updates the information (D) stored in the internal storage circuit.

Abstract: A noncontact transmission device (100) is provided with a monitoring clock oscillator (112) for outputting a monitoring clock (LF0) having a frequency lower than that of a system clock (CK0); a control circuit (108); a memory (114) having information (D) stored to be used by the control circuit (108); and a reset circuit (116). The control circuit (108) includes an internal storage circuit for storing the information (D) read out from the memory (114). The control circuit (108) reads out and updates the information (D) stored in the internal storage circuit from the memory (114) with an update period based on the monitoring clock (LF0). Furthermore, the control circuit (108) is reset with a reset period longer than the update period based on the monitoring clock (LF0), and, each time the control circuit (108) is reset, reads out the information (D) from the memory (114) and updates the information (D) stored in the internal storage circuit.

Abstract: A noncontact transmission device 100 is provided with a driver 106 for driving a coil 102; a system clock oscillator 110 for outputting a system clock; a monitoring clock oscillator 112 for outputting a monitoring clock LF0 having a frequency lower than that of the system clock CK0; and a control circuit 108. The control circuit 108 outputs a system clock oscillating control signal S60 based on the monitoring clock LF0 while being in a standby state and makes the system clock oscillator 110 intermittently output a system clock CK0 in synchronization with the control signal S60. In a period when the system clock CK0 is being outputted, the coil 102 is driven by a driver control signal SD and whether the device 200 to which data is to be transmitted is arranged or not is detected.