WIRELESS POWER TRANSMITTER, CONTROL CIRCUIT THEREOF, CHARGER, AND CALIBRATION METHOD OF FOREIGN OBJECT DETECTION BY POWER LOSS METHOD

摘要

A wireless power transmitter transmitting a power signal to a wireless power receiver, includes: a transmission antenna; an inverter circuit applying an AC driving signal to the transmission antenna; and a control circuit controlling the inverter circuit. The control circuit includes: a demodulator demodulating a control signal received by the transmission antenna from the wireless power receiver; a transmission power measurement part measuring transmission power to generate transmission power data; and a logic circuit that controls the inverter circuit based on power control data included in the control signal to change the transmission power, control the inverter circuit based on the control signal to be transmitted to the wireless power receiver to modulate the power signal, and perform foreign object detection by a power loss method based on transmission power data and reception power data included in the control signal. The logic circuit is configured to perform a calibration sequence.

主权项

1. A wireless power transmitter for transmitting a power signal to a wireless power receiver, comprising:
a transmission antenna including a transmission coil; an inverter circuit configured to apply an AC driving signal to the transmission antenna; and a control circuit configured to control the inverter circuit, wherein the control circuit comprises: a demodulator configured to demodulate a control signal received by the transmission antenna from the wireless power receiver; a transmission power measurement part configured to measure a transmission power to generate a transmission power data; and a logic circuit configured to (1) control the inverter circuit based on the power control data included in the control signal to change the transmission power, (2) control the inverter circuit based on the control signal to be transmitted to the wireless power receiver to modulate the power signal, and (3) perform foreign object detection by a power loss method based on the transmission power data and a reception power data included in the control signal, wherein the logic circuit is configured to perform a calibration sequence including: a first step of controlling the transmission power based on the power control data when the wireless power receiver is in a first load state; a second step of modulating the power signal and transmitting an acknowledgement (ACK) to the wireless receiver when first reception power data received in the first load state satisfies a first condition, and modulating the power signal and transmitting a non-acknowledgement (NACK) to the wireless receiver when the first reception power data does not satisfy the first condition; a third step of controlling the transmission power based on the power control data when the wireless receiver is in a second load state which is heavier than the first load state; a fourth step of modulating the power signal and transmitting an ACK to the wireless receiver when second reception power data received in the second load state satisfies a second condition, and modulating the power signal and transmitting a NACK to the wireless receiver when the second reception power data does not satisfy the second condition; and a fifth step of generating a data required for calibration based on at least the first reception power data the second reception power data, wherein the logic circuit is further configured to perform: a sixth step of forcibly transmitting an ACK even though the second reception power data does not satisfy the second condition when a first predetermined period of time has elapsed since the calibration sequence started, and of continuously waiting for the second reception power data satisfying the second condition; and a seventh step of generating data required for calibration when the second reception power data satisfying the second condition is received.