Rohm Co., Ltd.

Takeshi Nozawa

Tatsuya Iwasaki

Daisuke Uchimoto

Shingo Haruta

Kazuyoshi Yasuoka

Xun He

Isao Yamamoto

Masatoshi Watanabe

Manabu Miyata

Hideharu Hayashida

A rectifier circuit includes an H-bridge circuit, and rectifies an AC current that flows through a reception antenna. A smoothing capacitor smoothes the output of the rectifier circuit. A demodulator demodulates an FSK-modulated electric power signal. A first comparator compares a voltage Vat a first AC input terminal with a first threshold voltage V, and generates a first detection signal. A second comparator compares a voltage Vat a second AC input terminal with a second threshold voltage V, and generates a second detection signal. A clock generating circuit generates a frequency detection clock CLK_OUT that transits according to a predetermined edge type of the first detection signal and a predetermined edge type of the second detection signal. A frequency detection circuit detects the frequency of the frequency detection clock.

Wireless power receiving apparatus

The position misalignment detection device includes: a comparator configured to compare an electric current induced by a receiving coil in a receiver (RX) to which an electric power is transmitted from a transmitter (TX) with a non-contact power supply transmitter method; a frequency counter connected to the comparator, the frequency counter configured to count transmit frequency fi transmitted from the transmitter; and a register configured to store a counted value Fcounted by the frequency counter. There is provided the position misalignment detection device which can detect a position misalignment of the receiver on the transmitter during electric charging.

Position misalignment detection device and electronic apparatus

A control circuit is provided for a power receiver apparatus. A target voltage range setting unit sets an upper limit voltage Vand a lower limit voltage Vthat define a target voltage range REF to be set for a rectified voltage Vthat develops across a smoothing capacitor. An electric power control unit compares the rectified voltage Vwith each of the upper limit voltage Vand the lower limit voltage V, and generates a power control signal Dbased on the comparison result. A modulator modulates the power control signal D, and transmits the modulated signal to a wireless power transmitter apparatus via a reception coil. Upon detection of an oscillation state in the rectified voltage V, the target voltage range setting unit expands the target voltage range REF.

Power receiver control circuit for wireless power receiver apparatus

A first oscillator is configured to be switchable between a disabled state and an oscillation state in which a first clock signal CLKhaving a first frequency is generated. A second oscillator oscillates at a second frequency that is lower than the first frequency, so as to generate a second clock signal. In (i) a power transfer phase in which electric power is transmitted to a wireless power receiving apparatus, a controller instructs the first oscillator to oscillate, and generates a first pulse signal for controlling a driver according to the first clock signal. In (ii) a selection phase in which the presence or absence of the wireless power receiving apparatus is detected, the controller generates a second pulse signal for controlling the driver at a predetermined time interval, which is measured based on the second clock signal, and during which the first oscillator is set to the disabled state.

Wireless power transmitter

A control circuit of a wireless power receiver where the wireless power receiver includes a reception coil, a rectification circuit that rectifies a current of the reception coil, and a smoothing capacitor connected to an output of the rectification circuit. The control circuit includes a frequency detecting part configured to determine a frequency of a signal received by the reception coil in a detection period after a lapse of predetermined first time from a predetermined start timing before a lapse of predetermined second time; a modulation detecting part configured to determine whether the signal received by the reception coil is subjected to FSK (Frequency Shift Keying); and a standard determining part configured to determine a standard that a wireless power transmitter complies with, depending on the frequency detected by the frequency detecting part and the presence or absence of FSK.

Power receiver control circuit, control method of wireless power receiver, and electronic apparatus

A control circuit of a driving circuit for supplying a driving current to a light source includes: a pulse width modulation (PWM) input terminal configured to receive an input dimming pulse having an input duty ratio corresponding to a target light quantity of the light source, the input dimming pulse being pulse-width modulated; and a dimming controller configured to convert a period and a pulse width of the input dimming pulse into digital values, reconvert the digital values into an output dimming pulse having an output duty ratio which is the same as or different from the input duty ratio, and control the driving current to be on and off based on the output dimming pulse.

Driving circuit of light source and control circuit thereof, driving method of light source, lighting apparatus, and electronic device

A current driver connected with light emitting diode (LED) bars of the maximum number N of channels and driving LED bars of M channels to be driven, includes: PWM input terminal configured to receive PWM-modulated external dimming pulse having duty cycle with a target light quantity common to the LED bars of the M channels; pulse measurement circuit configured to measure period and pulse width of the external dimming pulse and generate digital period data and pulse width data; interface circuit connected to external processor and configured to receive enable data and phase difference setting data; M current sources of the M channels to be driven and respectively connected with corresponding LED bars, and configured to be On-and-Off-switched in response to internal dimming pulse; and pulse generator configured to generate M internal dimming pulses and distribute the M internal dimming pulses to the M current sources.

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Kyoto, Japan

Takeshi Nozawa