Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The inverter uses a full bridge that is controlled to deliver energy to the CCFL using pulse width modulation (PWM). Additionally, during striking of the CCFL, a wider initial energy pulse is used. During normal operation, a lower energy pulse is used.

Abstract: An integrated circuit driver is disclosed. The driver comprises a high side transistor and a low side transistor connected in series. The output of the driver is taken from the source of the high side transistor and the drain of the low side transistor. A bootstrap contact pad is connected to the output node. Connected to the bootstrap contact pad is a bootstrap capacitor that is also connected to a high side gate drive that selectively controls the high side transistor.

Abstract: A full wave sense amplifier for sensing a periodic current flowing through a discharge lamp is disclosed. The full wave sense amplifier comprises a first circuit for sensing the positive going portion of the periodic current. The amplifier also includes a second circuit for sensing the negative going portion of the periodic current. Finally, an output circuit for combining the negative going portion and the positive going portion into a current flow signal is provided.

Abstract: A lateral high voltage transistor device is disclosed. The transistor includes a gate, a drain, and a source. The drain is located apart from the gate to form an intermediate drift region. The drift region has variable dopant concentration between the drain and the gate. In addition, a spiral resistor is placed over the drift region and is connected to the drain and either the gate or the source of the transistor.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: An LDMOS transistor formed in an N-type substrate. A polysilicon gate is formed atop the N-type substrate. A P-type well is formed in the N-type substrate extending from the source side to under the polysilicon gate. A N+ source region is formed in the P-type well and adjacent to the polysilicon gate. A N+ drain region is formed in the N-type substrate and in the drain side of the polysilicon gate. Finally, an N-type drift region is formed between the N+ drain region and the polysilicon gate, wherein the N-type drift region does not extend to said polysilicon gate.

Abstract: A Class D amplifier circuit performs audio signal processing and other signal processing by using a bang-bang controller and a noise-shaping feedback network. The bang-bang controller triggers generation of a rectangular waveform that corresponds to changes in a control signal derived from an input analog signal, with the generation of the rectangular waveform being based on a comparison of the control signal with another signal derived from hysteresis associated with an output of a comparator. A filter filters the rectangular waveform to obtain an amplified output analog signal substantially representative of the input analog signal. The feedback network noise shapes the output analog signal, and feeds back the noise-shaped output analog signal and substracts it from the input analog signal.

Abstract: A Class D amplifier circuit performs audio signal processing and other signal processing by using a bang-bang controller and a noise-shaping feedback network. The bang-bang controller triggers generation of a rectangular waveform that corresponds to changes in a control signal derived from an input analog signal, with the generation of the rectangular waveform being based on a comparison of the control signal with another signal derived from hysteresis associated with an output of a comparator. A filter filters the rectangular waveform to obtain an amplified output analog signal substantially representative of the input analog signal. The feedback network noise shapes the output analog signal, and feeds back the noise-shaped output analog signal and substracts it from the input analog signal.

Abstract: The multiple lamp circuit for minimizing lamp current imbalance comprises at least one transformer comprising primary windings and secondary windings. Multiple lamps are coupled in serial to the secondary windings of the transformer. Multiple separated lamp drive circuits are spliced from the transformer's secondary windings. A current balancing resistance is connected at a common node of the multiple lamps and other terminal of the current balancing resistance is connected to ground. The impedance of the current balancing resistance is relatively high compared to the ones of the multiple lamps to generate a balancing current for one of the multiple lamps, thereby resulting a current that flows through the multiple lamps is approximately equal.

Abstract: A battery charger is provided that does not sink current from the battery during a reverse mode of operation. The battery charger includes upper and lower switching circuits, which alternately activate and deactivate to provide outgoing current flow. A comparator is coupled to the lower switching circuit to detect current flow into the upper and lower switching circuits. If this current flow is detected, a control circuit is provided that will deactivate the lower switching circuit to prevent subsequent incoming current flow. Further, a transistor is coupled to the lower switching circuit to detect the incoming current flow.

Abstract: A Class D amplifier circuit performs audio signal processing and other signal processing by using a bang-bang controller and a noise-shaping feedback network. The bang-bang controller triggers generation of a rectangular waveform that corresponds to changes in a control signal derived from an input analog signal, with the generation of the rectangular waveform being based on a comparison of the control signal with another signal derived from hysteresis associated with an output of a comparator. A filter filters the rectangular waveform to obtain an amplified output analog signal substantially representative of the input analog signal. The feedback network noise shapes the output analog signal, and feeds back the noise-shaped output analog signal and substracts it from the input analog signal.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: An LDMOS transistor formed in an N-type substrate. A polysilicon gate is formed atop the N-type substrate. A P-type well is formed in the N-type substrate extending from the source side to under the polysilicon gate. A N+ source region is formed in the P-type well and adjacent to the polysilicon gate. A N+ drain region is formed in the N-type substrate and in the drain side of the polysilicon gate. Finally, an N-type drift region is formed between the N+ drain region and the polysilicon gate, wherein the N-type drift region does not extend to said polysilicon gate.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.