Tetsuo Tateishi

Bio: Tetsuo Tateishi is an academic researcher. The author has contributed to research in topics: Inductor & Switched-mode power supply. The author has an hindex of 1, co-authored 1 publications receiving 208 citations.

DC to DC converter with high efficiency for light loads

Abstract: A DC to DC converter which maintains high efficiency over broad current ranges in a current mode switching regulator circuit without changing operational mode. A low ripple voltage is maintained over the entire load range and good voltage regulation is maintained with high efficiency. This is possible because the switching frequency is adjusted in accordance with the load without changing operational states, thus making it unnecessary to define plural states of operation. The timing of turning on the switch(es) varies since the switch(es) is (are) turned on when two set (ready) signals both become ready. For fixed frequency switching applications, switching pulses from a fixed frequency oscillator as a first set signal are skipped when a second set signal is not ready. On the other hand, for a variable frequency switching scheme which is implemented by driving the switching with a one-shot having a constant OFF time, the switching pulse is created after both set signals become active. A low pass filter is also used to dynamically adjust the minimum peak inductor current and to minimize ripple voltage for low load conditions so that a smaller output capacitor may be used.

Bidirectional wireless power transmission

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transceiver and device comprise an antenna including a parallel resonator configured to resonate in response to a substantially unmodulated carrier frequency. The wireless power transceiver further comprises a bidirectional power conversion circuit coupled to the parallel resonator. The bidirectional power conversion circuit is reconfigurable to rectify an induced current received at the antenna into DC power and to induce resonance at the antenna in response to DC power.

Transmitters for wireless power transmission

Abstract: Exemplary embodiments are directed to wireless power transfer. A wireless power transmitter includes a transmit antenna configured as a resonant tank including a loop inductor and an antenna capacitance. The transmitter further includes an amplifier configured to drive the transmit antenna and a matching circuit operably coupled between the transmit antenna and the amplifier. The transmitter also includes a capacitor integrating the antenna capacitance and a matching circuit capacitance.

Voltage regulator compensation circuit and method

Abstract: A method and circuit enable a voltage regulator to employ the smallest possible output capacitor that allows the regulator's output voltage to be maintained within specified boundaries for large bidirectional step changes in load current. This is achieved with a technique referred to as “optimal voltage positioning”, which keeps the output voltage within the specified boundaries while employing an output capacitor which has a combination of the largest possible equivalent series resistance (ESR) and lowest possible capacitance that ensures that the peak voltage deviation for a step change in load current is no greater than the maximum allowed. The invention can be used with regulators subject to design requirements that specify a minimum time T min between load transients, and with those for which no T min is specified. When no T min is specified, optimal voltage positioning is achieved by compensating the regulator to ensure a response that is flat after the occurrence of the peak deviation, which enables the output voltage to remain within specified limits regardless of how quickly load transients occur. Another embodiment enables the power consumption of the device being powered by the regulator to be reduced under certain circumstances, while still employing the smallest possible output capacitor that allows the regulator's output voltage to be maintained within specified boundaries. The invention is applicable to both switching and linear voltage regulators.

Multiple bi-directional input/output power control system

Abstract: A multiple bi-directional input/output power control system includes a network of functional blocks housed in a single enclosure, providing DC power to one or more DC loads, and providing control and internal pathways, sharing one or more AC and/or DC power inputs. The system feeds back AC power from the DC power source into an AC input connection, and the fed-back AC power is shared by other AC loads. The system operates at least one alternative source of DC in a dynamic manner, allowing maximization of power generating capability at respective specific operating conditions of the moment. Power isolation may be handled by an AC isolation block right at a power input. Therefore all other blocks within a multi-function power control unit (MFPCU) are isolated from AC ground.

Method and apparatus providing a multi-function terminal for a power supply controller

Abstract: A power supply controller having a multi-function terminal. In one embodiment, a power supply controller for switched mode power supply includes a drain terminal, a source terminal, a control terminal and a multi-function terminal. The multi-function terminal may be configured in a plurality of ways providing any one or some of a plurality of functions including on/off control, external current limit adjustments, under-voltage detection, over-voltage detection and maximum duty cycle adjustment. The operation of the multi-function terminal varies depending on whether a positive or negative current flows through the multi-function terminal. A short-circuit to ground from the multi-function terminal enables the power supply controller. A short-circuit to a supply voltage from the multi-function terminal disables the power supply controller. The current limit of an internal power switch of the power supply controller may be adjusted by externally setting a negative current from the multi-function terminal. The multi-function terminal may also be coupled to the input DC line voltage of the power supply through a resistance to detect an under-voltage condition, an over-voltage condition and/or adjust the maximum duty cycle of power supply controller. Synchronization of the oscillator of the power supply controller may also be realized by switching the multi-function terminal to power or ground at the desired times.