Lucent Technologies Inc.

At+t Corp.

Zarlink Semiconductor Limited

John K Moriarty, Jr

James B Archibald

A power converter controller is operable to control power provided to a load circuit coupled between a first voltage supply terminal and a first switching element by controlling the first switching element and to control power provided to an energy storage element coupled to the first switching element. The energy storage element is operable to provide a power supply. A first control terminal couples to a control input of the first switching element. A first load terminal couples to the first switching element and the charge storing element. A second switching element couples between the first load terminal and a second voltage supply terminal. Timing logic is operable to selectively provide a control signal at the first control terminal to control the first switching element and to selectively control the second switching element to supply power to the load circuit during a load powering phase by enabling the first and second switching elements, charge the energy storage element during a bootstrap charging phase by enabling the first switching element and disabling the second switching element, and allowing the load circuit to operate in isolation during a passive phase by disabling at least the first switching element.

Bootstrap supply for switched mode power converter

A boost power converter for powering a load with an AC source is disclosed. The boost power converter comprises an AC to DC conversion circuit, a resonator, and a boost circuit. The resonator includes an energy storage device and a resonant circuit, and alternately applies energy from the energy storage device to the resonant circuit for powering the load. The AC to DC conversion circuit generates a DC signal in response to the AC source. The boost circuit includes a choke for receiving the DC signal, a rectifier for electrically coupling the choke to the energy storage device, and a switching device for selectively coupling the choke to the resonant circuit for charging and discharging the choke. The resonator operates in full resonant mode with zero voltage switching. The boost power converter is well-suited for ballast applications that drive a fluorescent lamp.

Boost power converter for powering a load from an AC source

The input branch of the current mirror is responsive to a single input signal current and each output branch of the current mirror mirrors the input signal current to produce an output current proportional to (e.g., substantially equal to) the input signal current. In one embodiment, the input branch has an input mirror MOS transistor connected to a threshold voltage generator, the output branch has an output mirror MOS transistor connected in cascode to an output cascode MOS transistor, and all of the transistors operate in saturation. The threshold voltage generator may be implemented in different ways, including using four MOS transistors forming two current paths, such that, in one current path, two transistors have channel constants of X and 4X, respectively, and, in another current path, two transistors both have channel constants of A, which may be different from X. In this implementation, the input and output mirror transistors have channel constants of B, which may be different from X and A, and the output cascode transistor has a channel constant of 4X+A.

Critically-biased MOS current mirror

A boost power converter for powering a load with an AC power source. The boost power converter has an energy storage device, a resonant circuit, a resonator switch circuit, a boost inductor circuit with a boost inductor, and a boost switch circuit. The resonator switch circuit alternately connects the resonant circuit to different sides of the energy storage device, where power from the energy storage device is transferred by the resonant circuit to the load. The boost switch circuit selectively connects the boost inductor to the resonator switch circuit, such that the boost inductor is charged in one of two different directions depending on the phase of the AC power source. The boost power converter is well-suited for ballast applications that drive a fluorescent lamp.

Quasiresonant boost power converter with bidirectional inductor current

A buck-boost power converter for powering a load from an AC power source having a full resonant circuit for applying an alternating voltage to the load. A choke is connected to the full resonant circuit and a switching device switches the choke in quasi-resonant manner to an input power rectifier to produce high power factor power conversion.

Power converter with high power factor

A transformer-less electronic ballast for a gas-discharge lighting system having a power amplifier, with an input, driving a gas-discharge lamp in combination with reactive elements to form a resonant load. The lighting system includes a resistor for sensing current flowing in the resonant load, a comparator having an output coupled to the input of the power amplifier, a non-inverting input coupled to the resistor, and an inverting input coupled to the output of a ramp generator, polarity of the ramp signal being dependent on the output of the comparator. The comparator generates a first signal that is amplified by the power amplifier and applied to the load. The ramp generator generates a ramp signal in response to the first signal. The first signal is asserted by the comparator when the sensed current flowing in the load differs from the ramp signal.

Transformer replacement for a solid-state lighting ballast

Two methods are disclosed for providing a warm-up or pre-heat period for a gas-discharge lighting system, such as a fluorescent light. One method provides current to the lamp for a predetermined period of time to heat the filaments therein without significant ionization of the lamp. The second method provides current to the lamp to heat the filaments without significant ionization of the lamp until the voltage across the filament reaches a predetermined voltage. After the lamp is pre-heated, the current is increased to ionize the lamp.

Method for pre-heating a gas-discharge lamp

A gas-discharge lighting system having an inductor and at least two capacitors in combination with a gas discharge lamp, the inductor and capacitors forming a resonant system, the resonant frequency thereof being dependent upon whether the lamp is nonionized or ionized. The lamp is operated by driving the lamp, inductor, and capacitor combination with a signal of a first polarity and inverting the polarity when the signal current transitions a predetermined current level. This repeated until the polarity of the signal remains of one polarity longer than a predetermined time, at which time the signal is inverted. This is repeated indefinitely. The predetermined length of time is one-half the inverse of a minimum frequency greater than the ionized resonant frequency. To protect the lighting system from overload, if the signal current exceeds a predetermined level, then the polarity of the signal is inverted, effectively moving the frequency of the signal up away from the ionized resonant frequency, thereby reducing the power delivered to the lamp. This method is applicable to fluorescence lighting and other gas-discharge lamps, such as mercury and sodium vapor lamps.

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Reading, PA, United States of America

John K Moriarty, Jr