Nxp Usa, Inc.

Freescale Semiconductor,inc.

Wanfu Ye

Xiang Gao

Chongli Wu

Lingling Wang

Xuwei Zhou

Kai-wen Cheng

Zhendong Fei

Dongpeng Hou

Shunan Li

A critical conduction mode (CRM) bridgeless PFC system includes a PFC converter connected to an Alternating Current (AC) source, a zero-current detection (ZCD) circuit for detecting a zero-current state of the PFC converter, a zero-voltage switching (ZVS) detection circuit, and a processor. Voltage divider circuits receive a first voltage and a supply voltage from the PFC converter and the AC source. The ZCD circuit receives divided voltages generated by the voltage divider circuits and generates a ZCD signal. The ZCD signal is used by the ZVS detection circuit to generate a ZVS flag, which is used by the processor to control switching of first through fourth transistors of the PFC converter.

Bridgeless power factor correction converter with zero current detection circuit

A switching controller circuit for a power converter includes analog and digital control circuits, a clock enable circuit, and a digital pulse width modulation (PWM) circuit. When the power converter is in a standby mode, the switching controller circuit operates in an analog control mode by activating the analog control circuit. When the power converter is not in standby mode, the switching controller circuit activates the digital control circuit and operates in a digital control mode. The switching controller circuit uses inexpensive electronic components and consumes less power in the analog control mode, thereby reducing standby mode power consumption.

Switching controller circuit

A system and method for demodulating a wireless power signal onto which binary data has been modulated involves processing the wireless power signal with analog circuitry to produce a modified power signal in accordance with the type of demodulation used, periodically capturing digital samples of the modified power signal to produce a series of digital samples, applying, with an MCU, at least two digital filtering algorithms to the digital samples to determine transitions associated with the modulation, and recovering, with the MCU, the binary data as a function of the determined transitions. The demodulator is applicable to bidirectional power transfer capable devices and includes algorithms that can be applied similarly to both ASK and FSK demodulations with little or no modification.

Bidirectional communication demodulation for wireless charging system

The embodiments described herein provide a power transmitter for wireless charging of an electronic device and methods of its operation. The power transmitter uses an inverter configured to generate a square wave from a potentially wide ranging DC input voltage. The inverter is configured to generate the square wave with a duty cycle that results in a desired equivalent voltage output, effectively independent of the DC input voltage that is provided. Thus, by generating a square wave with a selectable duty cycle the inverter provides the ability to facilitate wireless power transfer with a wide range of DC input voltages. Furthermore, in some embodiments the power transmitter may provide improved power transfer efficiency using a quasi-resonant phase shift control strategy with adjustable dead time and a matching network that is dynamically selectable to more effectively couple with the transmitter coil combination being used to transmit power to the electronic device.

Wireless power transmitters with wide input voltage range and methods of their operation

A system controlled by firmware includes a memory and a processor. The memory includes a first memory block for storing non-programmable code used for performing key functions, and second and third memory blocks for storing programmable code used for performing normal functions. During operation, one of the second and third memory blocks in which the programmable code is being executed is an active memory block. After receiving new programmable code, the processor identifies the inactive memory block, stores the new programmable code therein, and switches to execute the new programmable code while continuing to perform the key functions using the non-programmable code.

System and method for updating firmware in real-time

An apparatus for measuring movement of an object has a quadrature incremental encoder for providing first and second phases of encoder pulses corresponding to incremental displacements of the object. A first counter counts edges of the encoder pulses according to the sense of the displacement. Clock pulse counts are also made. Acquiring movement data at periodic speed processing moments includes the decoder adjusting encoder pulse data from the first counter using a clock pulse count that is a function of a lapse of time between when the most recent edge of the encoder pulses and the speed processing moment. The clock pulse counts are reset by edges of the first and second phases of the encoder pulses when the decoder acquires the movement data.

Counter based circuit for measuring movement of an object

A BASK demodulator includes a signal modifying circuit and a low pass filter (LPF) that couples an amplifier to an output of the modifying circuit. The modifying circuit includes a signal scaling circuit, a rectifying circuit and an AC coupling circuit. A signal shaping circuit couples an output of the amplifier to an output of the demodulator. The signal scaling circuit scales an input BASK modulated signal to provide an unclipped scaled and biased alternating signal that alternates about a bias voltage at a minimum carrier frequency. The rectifying circuit rectifies the unclipped signal to provide a partially rectified signal that is decoupled by the AC coupling circuit to provide a clipped scaled and biased alternating signal. The LPF removes the signal from the clipped scaled and biased alternating signal to provide a demodulated signal, which then is amplified by the amplifier and shaped by the shaping circuit.

Growing community of inventors

Shanghai, China

Wanfu Ye