Abstract: A device includes a substrate is substantially transparent and includes a contact surface and an interface surface. The interface surface includes a plurality of electrical contacts. The device further includes a semiconductor die, which includes a plurality of connections, a first photo detector and a second photo detector. Each of the plurality of connections includes a connection bump formed thereon to couple to the plurality of electrical contacts of the interface surface of the substrate. The plurality of connections positioned relative to the first and second photo detectors to alter a directional response of at least one photo detector of the plurality of photo detectors.

Abstract: Systems and methods for a digital-to-charge converter (“DQC”) are disclosed. A DQC may include a converting circuit configured to receive a first digital signal indicative of a voltage across a capacitor coupled to an output pin of the digital-to-charge converter and to determine a present charge of the capacitor based at least in part on the first digital signal. The DQC may also include an error determining circuit coupled to the converting circuit, wherein the error determining circuit is configured to receive a second digital signal indicative of a target charge via an input pin of the digital-to-charge converter and to determine a difference between the target charge and the present charge. The DQC may further include a correction circuit coupled to the error determining circuit and configured to control a programmable current source to produce an analog signal at the output pin in response to the determined difference.

Abstract: In one embodiment, a method includes receiving outputs from multiple photodetectors, calculating a first ratio between first and second such outputs, calculating a second ratio between the first output and a difference corresponding to a flicker noise component obtained from the second output, and determining a contribution from multiple illumination types based at least in part on the first and second ratios. The method may also include obtaining multiple correction coefficients based at least in part on the determined contribution, and in turn determining an ambient light type present in proximity to the photodetectors using the correction coefficients and the first and second outputs.

Abstract: A system includes a plurality of photo detectors, which generate signals proportional to incident light. The system further includes an optical barrier adjacent to a surface and includes a control circuit. The optical barrier partially obstructs reflected light from reaching the plurality of photo detectors to produce a spatially dependent reflectance pattern that is dependent on a position of an object relative to a substrate. The control circuit determines a position of the object during a reflectance measurement cycle using each of the plurality of photo detectors by calibrating to ambient light conditions, measuring ambient plus reflected light, determining the reflected light and detecting the position of the object based on a ratio of the reflected light received by at least two of the plurality of photo detectors.

Abstract: An apparatus includes a housing having a front surface, a rear surface, and at least one sidewall therebetween and a plurality of optical windows formed in the housing to allow light to pass through from multiple directions. The apparatus further includes a plurality of photo detectors to generate electrical signals based on received light, where each of the plurality of photo detectors is disposed within a respective one of the plurality of optical windows. The apparatus also includes a control circuit coupled to the plurality of photo detectors to receive the electrical signals, determine light variations from the electrical signals, and determine a change in position of an object based on variation ratios of the light variations received by at least one pair of photo detectors within the plurality of photo detectors in response to determining the light variations.

Abstract: Techniques are disclosed relating to analog-to-digital converters in integrated circuits. In one embodiment, a second-order delta-sigma analog-to-digital converter (ADC) is disclosed. The ADC includes a second-order integrator adapted to second-order integrate a value at a first node, where the first node is coupled to an input of the ADC. The ADC also includes a comparator coupled to an output of the second-order integrator. The ADC further includes a digital-to-analog converter (DAC) coupled between an output of the comparator and the first node. The DAC is adapted to receive a digital output of the comparator and to generate a first charge or a second charge. The DAC includes a first charge pump adapted to produce the first charge and a second charge pump adapted to produce the second charge. The first and second charges are asymmetric.

Abstract: Systems and methods for advanced monitoring and control using an LED driver in an optical processor are described. In an embodiment, a monitoring and control circuit may include a light-emitting diode (LED) driver including a control input, an output, and a node, wherein the output is coupled to an LED. The circuit may also include a multiplexer coupled to the node of the LED driver, an analog-to-digital converter coupled to the multiplexer, and a controller coupled to the analog-to-digital converter and to the control input of the LED driver, wherein the LED driver is coupled to drive the output with a first voltage supply that is independent from a second voltage supply that is coupled to drive the controller.

Abstract: A capacitor is charged synchronously with the beginning of an ON portion of a pulse width modulated (PWM) signal to generate a voltage across the capacitor using charging current sourced from an inductor on a primary side of a transformer. The voltage is supplied as a supply voltage to control circuitry in an integrated circuit used to generate the pulse width modulated signal. The charging is stopped when either the charging current goes above a predetermined charging current level or when the capacitor voltage goes above a predetermined capacitor voltage.

Abstract: A method for gesture recognition in an optical system using a touchless slider is shown. The touchless slider has first and second reference points positioned along an axis in an optical system. The method includes obtaining a plurality of first and second reflectance values by measuring an amplitude of light reflected from an object relative to the first and second reference points, respectively, wherein each first and second reflectance value corresponds to a different point in time. The plurality of first and second reflectance values are compared to identify a plurality of ratio values between the first and second reflectance values, wherein each of the plurality of ratio values corresponds to one of the points in time. At least one of a position and a direction of movement of the object relative to the first and second reference points is determined based on the identified plurality of ratio values.

Abstract: A system having an infrared receiver is shown, where the system includes an infrared receiver circuit configured to receive an infrared data signal using a receive photodiode and compensate for an ambient light level incident on the receive photodiode by generating a DC ambient current signal, where the DC ambient current signal is accessible external to the infrared receiver circuit. The system also includes a control circuit configured to receive the DC ambient current signal and, responsive thereto, determine the ambient light level and generate a display illumination control signal accordingly.

Abstract: A smoke alarm comprises smoke detection circuitry for detecting smoke and generating a detection signal responsive thereto. Proximity detection circuitry generates a proximity detection signal responsive to detection of an object within in a selected distance of the smoke alarm. Alarm generation circuitry generates an audible alarm responsive to the detection signal. The audible alarm may be deactivated for a predetermined period of time responsive to at least one proximity detection signal.

Abstract: An optical gesture recognition system is shown having a first light source and a first optical receiver configured to receive reflected light from an object when the first light source is activated and output a first measured reflectance value corresponding to an amplitude of the reflected light. A processor is configured to receive the first measured reflectance value and to compare the first measured reflectance value at first and second points in time to track motion of the object and identify a gesture of the object corresponding to the tracked motion of the object.

Abstract: A communication device is disclosed having optical and near-field communication capability. The device includes an optical transceiver circuit fabricated on an integrated circuit die and configured to transmit and receive far field signals. A near field transceiver circuit is also fabricated on the integrated circuit die and is configured to transmit and receive near-field electro-magnetic signals. Control circuitry is provided to selectively enable the optical transceiver circuit and the near field transceiver circuit responsive to an external control signal.

Abstract: A system having an infrared receiver is shown, where the system includes an infrared receiver circuit configured to receive an infrared data signal using a receive photodiode and compensate for an ambient light level incident on the receive photodiode by generating a DC ambient current signal, where the DC ambient current signal is accessible external to the infrared receiver circuit. The system also includes a control circuit configured to receive the DC ambient current signal and, responsive thereto, determine the ambient light level and generate a display illumination control signal accordingly.

Abstract: A ring detect circuit is shown that includes a regenerative latch configured to be coupled to a telephone line. The regenerative latch is configured to generate a fast transient signal in response to a ring signal on the telephone line. The latch is coupled to an isolation transformer through a capacitor. The fast transient passes across the capacitor and through the transformer. A comparator detects the fast transient and, responsive thereto, generates a ring detect signal.

Abstract: Disclosed is a switch driver circuit is shown where the circuit can control current driven devices and drive devices across a capacitive barrier. A mode control signal determines whether the circuit is in a current mode or a capacitive mode. In current mode, the circuit provides a current output signal at an output of the circuit in response to a subject signal, such as an ON switch control signal for a hook switch application. In capacitive mode, the circuit provides a clocked output signal at the output of the circuit in response to the subject signal, such that the clocked output signal can pass across a capacitive isolation barrier.

Abstract: An optoisolator device is shown having a die attachment device with a planar surface. A first circuit die has first and second planar surfaces and a first side surface. A receiver circuit and a first photodiode are formed on the first planar surface of the first circuit die, where the first photodiode is electrically coupled to the receiver circuit. The second planar surface of the first circuit die is attached to the planar surface of the die attachment device. A second circuit die has a transmitter circuit that includes a first light emitting diode and is attached to the die attachment device in a position adjacent to the first side surface of the first circuit die. A clear plastic layer is formed on the planar surface of the die attachment device over the first and second circuit dies. An opaque layer may be formed over the clear plastic layer.

Abstract: A hook switch circuit is shown wherein two high-voltage bipolar transistors, a PNP transistor Q1 and a NPN transistor Q2. that are connected in a regenerative feedback manner to form a bi-stable latch. The regenerative structure permits the use of low beta transistors that may be turned on with a low control current, but still conduct a sufficient off-hook current. Also shown is a polarity steering regenerative switch (MP1, MP2) that provides a power supply voltage from a telephone line pair and may be adapted for a polarity signal and can be combined with a current mirror (MP7) to produce a current signal proportional to the line voltage (LV1).

Abstract: The present invention is directed toward a method and apparatus for transferring data across an isolation barrier using high speed analog encoded signals. A line side circuit interfaces with tip and ring contacts on one side of a capacitive isolation barrier that isolates the line side circuit from a modem side circuit. During an on-hook state, the line side circuit converts an analog line side voltage signal to a frequency signal and then encodes the frequency signal into a high frequency pulse-width-modulated (PWM) signal. The high frequency PWM signal is transmitted across the capacitive isolation barrier to the modem side circuit. During an off-hook state, the analog line side voltage is again encoded into a high frequency pulse-width-modulated (PWM) signal for transmission across the isolation barrier. The modem side circuit recovers the transmitted PWM signal and converts it into a digital count value that represents the amplitude of the analog voltage observed at the tip and ring.

Abstract: A caller ID circuit is shown that uses resistors as a caller ID interface to a telephone line pair. The circuit includes a differential transconductance amplifier coupled to the telephone line pair using resistors and a common mode canceling transconductance amplifier coupled to the telephone line pair using the resistors. The invention also includes a gyrator transconductance amplifier coupled to the differential transconductance amplifier and the common mode canceling transconductance amplifier that is configured to generate an output current corresponding to a caller ID signal present at the telephone line pair. In a further refinement of the invention, the resistors are accurate resistors. In another refinement of the invention, the circuit further includes an analog to digital converter (ADC) coupled to the gyrator transconductance amplifier, where the ADC converts the output current from the gyrator transconductance amplifier into a pulse-width-modulated (PWM) signal.