Abstract: A local minimum of a current monitoring signal is identified by a starter unit that turns off a fluorescent lamp without using a wall switch. Closing a main switch in the starter unit stops an illuminating current from flowing through a gas in the lamp. The local minimum of the current monitoring signal is reached when an increasing valid sample is identified following four valid samples. A sample is valid if it does not differ from the preceding valid sample by more than a threshold difference based on known properties of the signal. By skipping invalid samples, the local minimum is accurately determined to have been reached despite transient noise spikes in the signal that would trip any voltage threshold used to locate the local minimum. When the main switch is opened at a predetermined time after the local minimum, the illuminating current does not again flow through the gas.

Abstract: A legacy-type fluorescent lamp fixture involves a magnetic ballast and a starter unit socket. Power savings are realized by using a retrofit fluorescent lamp assembly in place of the fluorescent lamp that would ordinarily by held in the fixture. The retrofit assembly may, for example, have a smaller fluorescent lamp. A digitally controlled electronic ballast within the retrofit assembly drives the smaller fluorescent lamp efficiently, thereby achieving power savings. In addition, an RF-enabled switch is installed in the starter unit socket. The RF-enabled switch communicates multi-bit digital control signals in serial fashion from the starter socket, through existing wires of the fixture, through the lamp holders of the fixture, and into the retrofit assembly. The electronic ballast receives these signals, decodes them, and in response turns on or turns off its lamp as commanded. Additional power savings are thereby achieved by keeping the lamp off when it is not needed.

Abstract: A fluorescent lamp starter unit determines whether the lighting fixture into which it has been plugged is in a first or second state. The lamp is on in the first state and off in the second state. If the fixture is in the first state then the starter unit uses a first method to detect ballast type, whereas if the fixture is in the second state then the starter unit uses a second method to detect ballast type. In one example, the first method involves turning on the power switch of the starter unit at a time after a zero-crossing and then using the periodicity of a transient switch current signal to determine ballast type, whereas the second method involves turning on the power switch at the time of the zero-crossing and then using peak amplitude information of the transient switch current to determine ballast type.

Abstract: A lighting system includes a master that controls a plurality of light fixtures via wireless RF communications. An ambient light sensor in the master is used to monitor total ambient light and to prevent excessive illumination. In an auto-calibration process, the master makes ambient light measurements A, B and C when the light fixtures are illuminating an area at a minimum setting, at a maximum setting, and at an intermediate setting, respectively. A first threshold is set to be approximately (B?A). A second threshold is set to be slightly larger than (B?A)+(B?C). In normal system operation, total ambient light measurements are taken and compared to the two thresholds. In one example, if detected brightness is lower than the first threshold then the system is set at its maximum illumination setting, whereas if detected brightness is greater than the second threshold then the system is set at its intermediate illumination setting.

Abstract: A local minimum of a current monitoring signal is identified by a starter unit that turns off a fluorescent lamp without using a wall switch. Closing a main switch in the starter unit stops an illuminating current from flowing through a gas in the lamp. The local minimum of the current monitoring signal is reached when an increasing valid sample is identified following four valid samples. A sample is valid if it does not differ from the preceding valid sample by more than a threshold difference based on known properties of the signal. By skipping invalid samples, the local minimum is accurately determined to have been reached despite transient noise spikes in the signal that would trip any voltage threshold used to locate the local minimum. When the main switch is opened at a predetermined time after the local minimum, the illuminating current does not again flow through the gas.

Abstract: A legacy-type fluorescent lamp fixture involves a magnetic ballast and a starter unit socket. Power savings are realized by using a retrofit fluorescent lamp assembly in place of the fluorescent lamp that would ordinarily by held in the fixture. The retrofit assembly may, for example, have a smaller fluorescent lamp. A digitally controlled electronic ballast within the retrofit assembly drives the smaller fluorescent lamp efficiently, thereby achieving power savings. In addition, an RF-enabled switch is installed in the starter unit socket. The RF-enabled switch communicates multi-bit digital control signals in serial fashion from the starter socket, through existing wires of the fixture, through the lamp holders of the fixture, and into the retrofit assembly. The electronic ballast receives these signals, decodes them, and in response turns on or turns off its lamp as commanded. Additional power savings are thereby achieved by keeping the lamp off when it is not needed.

Abstract: A local minimum of a current monitoring signal is identified by a starter unit that turns off a fluorescent lamp without using a wall switch. Closing a main switch in the starter unit stops an illuminating current from flowing through a gas in the lamp. The local minimum of the current monitoring signal is reached when an increasing valid sample is identified following four valid samples. A sample is valid if it does not differ from the preceding valid sample by more than a threshold difference based on known properties of the signal. By skipping invalid samples, the local minimum is accurately determined to have been reached despite transient noise spikes in the signal that would trip any voltage threshold used to locate the local minimum. When the main switch is opened at a predetermined time after the local minimum, the illuminating current does not again flow through the gas.

Abstract: A starter unit (for example, an RF-enabled and replaceable starter unit) has an ability both to turn on and to turn off a fluorescent lamp. The starter unit detects whether a ballast in the circuit with the fluorescent lamp is of a first type (for example, an L-type ballast) or is of a second type (for example, a C-type ballast). If the determination is that the ballast is of the first type, then the starter unit turns off the lamp in a first way (for example, using C-type timing and then using L-type timing alternatingly). If the determination is that the ballast is of the second type, then the starter unit turns off the lamp in a second way (for example, using only C-type timing). The same starter unit design is usable both in single-lamp fixtures and in multi-lamp fixtures where a mix of ballast types may be used.

Abstract: In a circuit that turns off a fluorescent lamp, clamping circuitry is provided to dissipate energy stored in a ballast when the lamp is being turned off. In a normal state in which the lamp is on, or in a normal state in which the lamp is off, clamping is not performed as long the VDS of a power switch is below a voltage A. In a lamp turn off operation, the switch is turned on for a time period to extinguish the lamp, and is then made to operate as a clamp (operate in its linear region) for a second period of time to dissipate energy that was stored in the ballast. Clamping in the linear region continues for VDS voltages down to B as ballast energy is dissipated, where B is smaller than A. By clamping down to the lower voltage B, re-ignition of the lamp is prevented.

Abstract: A starter unit (for example, an RF-enabled and replaceable starter unit) has an ability both to turn on and to turn off a fluorescent lamp. The starter unit detects whether a ballast in the circuit with the fluorescent lamp is of a first type (for example, an L-type ballast) or is of a second type (for example, a C-type ballast). If the determination is that the ballast is of the first type, then the starter unit turns off the lamp in a first way (for example, using C-type timing and then using L-type timing alternatingly). If the determination is that the ballast is of the second type, then the starter unit turns off the lamp in a second way (for example, using only C-type timing). The same starter unit design is usable both in single-lamp fixtures and in multi-lamp fixtures where a mix of ballast types may be used.

Abstract: A starter unit (for example, an RF-enabled and replaceable starter unit) has an ability both to turn on and to turn off a fluorescent lamp. The starter unit detects whether a ballast in the circuit with the fluorescent lamp is of a first type (for example, an L-type ballast) or is of a second type (for example, a C-type ballast). If the determination is that the ballast is of the first type, then the starter unit turns off the lamp in a first way (for example, using C-type timing and then using L-type timing alternatingly). If the determination is that the ballast is of the second type, then the starter unit turns off the lamp in a second way (for example, using only C-type timing). The same starter unit design is usable both in single-lamp fixtures and in multi-lamp fixtures where a mix of ballast types may be used.

Abstract: An electrostatic discharge (ESD) transistor structure includes a self-aligned outrigger less than 0.4 microns from a gate electrode that is 50 microns wide. The outrigger is fabricated on ordinary logic transistors of an integrated circuit without severely affecting the performance of the transistors. The outrigger is used as an implant blocking structure to form first and second drain regions on either side of a lightly doped region that underlies the outrigger. The self-aligned outrigger and the lightly doped region beneath it are used to move the location of avalanche breakdown upon an ESD event away from the channel region. Durability is extended when fewer “hot carrier” electrons accumulate in the gate oxide. A current of at least 100 milliamperes can flow into the drain and then through the ESD transistor structure for a period of more than 30 seconds without causing a catastrophic failure of the ESD transistor structure.

Abstract: A method of fabricating a high-performance capacitor that may be incorporated into a standard CMOS fabrication process suitable for submicron devices is described. The parameters used in the standard CMOS process may be maintained, particularly for the definition and etch of the lower electrode layer. To reduce variation in critical dimension width, an Anti-Reflective Layer (ARL) is used, such as a Plasma Enhanced chemical vapor deposition Anti-Reflective Layer (PEARL) or other Anti-Reflective Coatings (ARCS), such as a conductive film like TiN. This ARL formation occurs after the capacitor specific process steps, but prior to the masking used for defining the lower electrodes. A Rapid Thermal Oxidation (RTO) is performed subsequent to removing the unwanted capacitor dielectric layer from the transistor poly outside of the capacitor regions, but prior to the PEARL deposition.

Abstract: A clock input filter uses a first programmable low-pass delay element to filter during a low period of an input clock signal and to output a SET signal. The clock input filter uses a second programmable low-pass delay element to filter during a high period of the input clock signal and to output a RESET signal. A latch is set and reset by the SET and RESET signals. The latch outputs a filtered version of the input signal that has the same approximate duty cycle as the input signal. A pair of gates generates a corresponding pair of duty cycle adjusted versions of the input signal. Output multiplexing circuitry is provided to output either the output of the latch, or an increased duty cycle version of the input signal, or a decreased duty cycle version of the input signal, or an unfiltered version of the input signal.

Abstract: The present disclosure describes a technique for reducing east-west geometry mismatch between the top and bottom of a raster display. This is accomplished by generating a horizontal correction signal that does not have any discontinuities. Since there are no discontinuities in the horizontal correction signal, the horizontal deflection current signal will not be distorted. As a result, there will be no east-west geometry mismatch between the top and bottom of the raster display.

Abstract: A programmable spread spectrum clock generator (SSCG) reduces electromagnetic interference by spreading the frequency bandwidth of an output signal. The rate at which the frequency of the output signal changes, as well as other aspects of the output signal, are software programmable. The programmable SSCG receives a periodic signal whose cycles have substantially identical periods and outputs the output signal whose cycles have periods that vary smoothly over a plurality of cycles of the periodic signal. The programmable SSCG generates a control signal using the periodic signal. The programmable SSCG includes a variable delay element that generates the output signal by delaying the periods of the periodic signal based on the magnitude of the control signal. The output signal is generated without using a phase locked loop. Moreover, successive cycles of the output signal rarely have identical periods.

Abstract: A microcontroller has an integrating analog-to-digital converter (IADC) with an in-situ autocalibrating functionality. On-chip autocalibrating circuitry supplies a first predetermined analog input voltage to the IADC and obtains a first data value from the IADC. The autocalibrating circuitry supplies a second predetermined analog input voltage to the IADC and obtains a second data value. The first and second data values are used to calibrate the IADC such that if the first input voltage is later supplied to the IADC, then the IADC will output a first predetermined desired digital output value and such that if the second input voltage is later supplied to the IADC, then the IADC will output a second predetermined desired digital output value. The first and second analog input voltages are generated on-chip so the calibration is performed automatically without having to supply external calibrating signals to the microcontroller. Other related methods and circuitry is disclosed.

Abstract: A microcontroller receives a supply voltage (VCC) from one or more batteries. Rather than automatically resetting the microcontroller if VCC drops below a VBO voltage, a latent VBO reset circuit does not reset the processor if VCC drops below a second voltage (VBO) as long as VCC does not fall so low that a power on reset (POR) circuit of the latent VBO reset circuit is tripped. The processor continues to operate as long as it can below VBO, thereby maximizing battery usage. When VCC rises to a third voltage (for example, due to battery replacement), then the latent VBO reset circuit automatically resets the processor to remove potential ill-effects of having operated below VBO. User data stored in volatile memory is not lost during battery replacement. A special VBO bit in a processor-readable status register indicates that the microcontroller operated below VBO.

Abstract: The infrared LED of an IrDA module transmits IR energy with a peak wavelength (for example, 875 nm) appropriate for IrDA communication. This peak wavelength is lower than is the wavelength (for example, 940 nm) used in ordinary IR remote controls (RC). The IrDA LED does, however, transmit some energy at the wavelength of the peak sensitivity of an RC receiver. When making an IrDA transmission, the IrDA LED is driven with a lower amount of current. When making an RC transmission, the IrDA LED is driven with an increased amount of current such that higher wavelength emissions received by the RC receiver are of adequate power to realize RC communication. A passive circuit is disclosed for automatically increasing IrDA LED current during RC transmissions. The circuit involves an inductor that shunts current around a current-limiting resistor used to limit LED drive current.

Abstract: An Improved Circuit Design and Optics System for infrared Signal Transceivers is disclosed. The preferred system includes an IR transceiver assembly that is easily grasped by assemblers. Furthermore, the primary and secondary lenses associated with the transceiver system are easier to manufacture than are current lens designs. Also, the heretofore critical lens separation between the infrared emitting and infrared detection devices and the primary lens is rendered a flexible dimension, dependent only upon the particular appliance in which the system is installed. The present invention permits the stand for infrared emitting and infrared detection devices to be eliminated as a result of exchanging a non-imaging transceiver system with the current imaging transceiver system. The present invention further comprises assembling or otherwise combining infrared emitting and infrared detection devices into a single infrared emitting/infrared detection device stack.