Abstract: Third order distortion is reduced in a CMOS transconductor circuit that includes a first N-channel transistor and a first P-channel transistor, gates of the first N-channel transistor and the first P-channel transistor being coupled to receive an input signal. Drains of the first N-channel transistor and first P-channel transistor are coupled to an output conductor. A first degeneration resistor is coupled between a source of the first P-channel transistor and a first supply voltage and a second degeneration resistor is coupled between a source of the first N-channel transistor and a second supply voltage. A first low impedance bypass circuit is coupled between the sources of the first P-channel transistor and the first N-channel transistor.

Abstract: A relaxation oscillator reduces temperature sensitivity and phase noise at low offset frequency by periodically swapping a first current and a second current so that after the first current has been input to a first pair of circuits and the second current has been input to a second pair of circuits, the second current is input to the first pair of circuits and the first current is input to the second pair of circuits.

Abstract: In a wireless power transfer system with multiple receivers, receiver management may be necessary to effectively provide power to the multiple receivers. In one implementation, receiver management includes sweeping or stepping the transmitter resonant and/or operating frequency. In another implementation, receiver management includes receiver self-management, in which the receiver load current duty cycle is controlled to maintain receiver voltage even in the presence of multiple receivers. In another implementation, receiver management includes receiver self-management, in which one or more receivers use a time-sharing heuristic to identify when other receivers are charging and wait to begin receiving a transfer of power until another receiver has stopped receiving a transfer of power.

Abstract: A wireless charging system includes a transmitter with tunable reactive components (such as capacitance or inductance). A metric related to power transfer from the transmitter through a coil is used to determine an amount to modify a Parameter. One metric is equal to |Vs|·|Is|·cos(?)·(Vcoil_ref/Vcoil), where |Vs| is magnitude of the power source voltage, |Is| is magnitude of the power source current, ? is phase difference between the power source voltage and power source current, Vcoil_ref is a normalization value, and Vcoil is voltage across the coil. The transmitter can further include a phase tracking and adjustment loop (such as a phase-locked loop).

Abstract: A system includes a master device and multiple slave devices. The system also includes multiple bus interfaces forming a communication bus that couples the master and slave devices. Each bus interface includes a primary interface unit configured to communicate over first and second buses, where the first and second buses form a portion of the communication bus. Each bus interface also includes a secondary interface unit configured to communicate with the primary interface unit and to communicate with one of the slave devices over a third bus. Each bus interface further includes an isolator configured to electrically isolate the primary interface unit and the secondary interface unit. The primary interface unit is configured to receive multiple commands over the first bus, execute a first subset of commands, transmit a second subset of commands over the second bus, and transmit a third subset of commands over the third bus.

Abstract: In a wireless power transfer system with multiple receivers, receiver management may be necessary to effectively provide power to the multiple receivers. In one implementation, receiver management includes sweeping or stepping the transmitter resonant and/or operating frequency. In another implementation, receiver management includes receiver self-management, in which the receiver load current duty cycle is controlled to maintain receiver voltage even in the presence of multiple receivers. In another implementation, receiver management includes receiver self-management, in which one or more receivers use a time-sharing heuristic to identify when other receivers are charging and wait to begin receiving a transfer of power until another receiver has stopped receiving a transfer of power.

Abstract: A transmitter includes an alternating current power source with tunable parameters. A tunable parameter may be capacitance, inductance, or frequency. A metric related to power transfer from the transmitter through a coil is used to determine an amount to modify a parameter. One metric is equal to |Vs|·|Is|·cos(?), where |Vs| is magnitude of the power source voltage, |Is| is magnitude of the power source current, and ? is phase difference between the power source voltage and power source current. Another metric is equal to |Vs|·|Is|·cos(?)·(Vcoil_ref/Vcoil), where |Vs| is magnitude of the power source voltage, |Is| is magnitude of the power source current, ? is phase difference between the power source voltage and power source current, Vcoil_ref is a normalization value, and Vcoil is voltage across the coil. The transmitter may further include a phase tracking and adjustment loop; for example, a phase-locked loop (PLL).

Abstract: A system includes a master device and multiple slave devices. The system also includes multiple bus interfaces forming a communication bus that couples the master and slave devices. Each bus interface includes a primary interface unit configured to communicate over first and second buses, where the first and second buses form a portion of the communication bus. Each bus interface also includes a secondary interface unit configured to communicate with the primary interface unit and to communicate with one of the slave devices over a third bus. Each bus interface further includes an isolator configured to electrically isolate the primary interface unit and the secondary interface unit. The primary interface unit is configured to receive multiple commands over the first bus, execute a first subset of commands, transmit a second subset of commands over the second bus, and transmit a third subset of commands over the third bus.

Abstract: An oscillator, including amplifier circuitry and resonant circuitry, for providing an oscillation signal with a controllable frequency while maintaining a substantially constant steady state magnitude. Controllable reactive circuitry, included as part of the amplifier circuitry, has a reactance which can be controlled such that the resistive components of the amplifier circuitry and resonant circuitry impedances remain substantially equal. When in the form of serially coupled, controllable capacitances, the controllable reactive circuitry is controlled such that a ratio of changes in the controllable capacitances is approximately equal to a negative ratio of the capacitance values.

Abstract: Phase-locked loop (PLL) circuitry in which a sampling phase detector samples the output signal in accordance with the reference signal and a frequency detector detects the output signal frequency in accordance with the reference signal.

Abstract: A phase-frequency detection system and method for enhancing performance of the frequency detector in a phase-frequency detection system. Filtering of the frequency detector inputs makes operation of the frequency detector more robust in the presence of intersymbol interference within the incoming data signal and other non-ideal characteristics such as noise and crosstalk.

Abstract: A semiconductor device includes a semiconductor substrate, an electrode disposed on an upper surface of the substrate, and a set of one or more transistor element(s) disposed on the upper surface of the substrate. The set of transistor element(s) compactly surrounds the electrode with a threshold distance. In one embodiment, the set also compactly surrounds a via hole. In another, the element(s) comprises a bipolar junction transistor that has an aggregate emitter length of not less than 10 microns. In still another embodiment, the device is coupled to a RF circuit for power amplification.

Abstract: A semiconductor device includes a semiconductor substrate, an electrode disposed on an upper surface of the substrate, and a set of one or more transistor element(s) disposed on the upper surface of the substrate. The set of transistor element(s) compactly surrounds the electrode with a threshold distance. In one embodiment, the set also compactly surrounds a via hole. In another, the element(s) comprises a bipolar junction transistor that has an aggregate emitter length of not less than 10 microns. In still another embodiment, the device is coupled to a RF circuit for power amplification.