Abstract: A touch screen controller includes driving circuitry coupled to a conductive line through a resistance and drives that conductive line with a driving signal passed through the resistance at a drive frequency. Sensing circuitry is coupled to that conductive line and senses a voltage at that conductive line, the voltage being a function of a capacitance seen by that conductive line. Analog to digital conversion circuitry is coupled to the sensing circuitry and samples the sensed voltage at a sampling frequency to produce samples. Processing circuitry is coupled to the analog to digital conversion circuitry and directly calculates a tangent of a phase shift of the voltage due to the resistance and the capacitance from the samples, and determines a self touch value for that conductive line as a function of the tangent of the phase shift of the voltage.

Abstract: An electronic device includes a voltage divider producing different reference voltages. Dummy pixels each are formed by a transfer gate transistor having a first conduction terminal coupled to a floating diffusion node, a second conduction terminal, and a control node coupled to a first gate signal line, a transmission gate coupled between one of the plurality of taps and the second conduction terminal of the transfer gate transistor, a floating diffusion capacitor coupled between the floating diffusion node and ground, a transistor having a first conduction terminal coupled to the floating diffusion node, a second conduction terminal, and a control terminal coupled to a second gate signal line, and a reset transistor having a first conduction terminal coupled to the upper reference voltage, a second conduction terminal coupled to the second conduction terminal of the transistor, and a control terminal coupled to a reset signal line.

Abstract: Transient overvoltage suppression is provided by discharging through a Metal Oxide Varistor (MOV) and Silicon Controlled Rectifier (SCR) which are connected in series between power supply lines. The SCR has a gate that receives a trigger signal generated by a triggering circuit coupled to the power supply lines. A trigger voltage of the triggering circuit is set by a Transil™ avalanche diode.

Abstract: A low drop-out (LDO) voltage regulator circuit includes a power transistor having a control terminal configured to receive a control signal and an output terminal coupled to an output node. A current regulation loop senses current flowing through the power transistor and modulates the control signal to cause the power transistor to output a constant current to the output node. A voltage regulation loop senses voltage at the output node and modulates the control signal to cause the power transistor to deliver current to the output node so that an output voltage at the output node is regulated. The current regulation loop includes a bipolar transistor connected to the control terminal of the power transistor, where a base terminal of the bipolar transistor is driven by a signal dependent on a difference between the sensed current flowing through the power transistor and a reference.

Abstract: A device includes a force driver applying a force signal to a force node associated with a mutual capacitance between the force node and a sense node. A sensing circuit receives a sense signal from the sense node associated with the mutual capacitance between the force node and the sense node, and generates an output indicative of the sensed mutual capacitance. A control circuit controls the generation of the force signal to alternate between at least two different frequencies by generating consecutive pulses, with a given pulse of the consecutive pulses at a first of the at least two different frequencies. In a first operating state, a next pulse immediately succeeding the given pulse is at a second of the at least two different frequencies, and in a second operating state the next pulse immediately succeeding the given pulse is at the first of the at least two different frequencies.

Abstract: A circuit includes a force driver to apply a force signal to a force node associated with a mutual capacitance to be sensed, and a charge to voltage converter having an input coupled to receive a sense signal from a sense node associated with the mutual capacitance to be sensed. The charge to voltage converter includes an integrator circuit to integrate the sense signal to sense the mutual capacitance, an input switch between the input of the charge to voltage converter and an input of the integrator circuit, and a reset switch between an output of the integrator circuit and the input of the integrator circuit. A control circuit controls generation of the force signal to alternate between at least two different frequencies and generates, for each half cycle of the force signal, a first signal for closing the input switch and a second signal for closing the reset switch.

Abstract: A touch screen controller identifies an island in a matrix of acquired touch data values. A first sharpness of the island is calculated and a second sharpness of the island is calculated if the calculated first sharpness is greater than a sharpness threshold. A dynamic strength threshold is then determined as a function of the second sharpness if a variance of the island is greater than a dynamic variance threshold. A determination is then made that the identified island is a valid stylus island if a peak strength of the island is greater than the dynamic strength threshold.

Abstract: A data frame in a touch capacitive sensing circuit includes both mutual capacitance data and self capacitance data. The mutual capacitance data and self capacitance data of the frame are filtered to define mutual capacitance and self capacitance islands. Centroids of the mutual capacitance and self capacitance islands are calculated and then processed in a weighted mixing operation to produce a hybrid centroid that more accurately locates the coordinates of a detected touch/hover.

Abstract: A touch screen controller includes input circuitry receiving touch data from the touch screen. Processing circuitry acquires touch data from the input circuitry in a self-capacitance sensing mode, locates a force island and locates a sense island. A length of the force island and a length of the sense island is calculated. If the length of the force island is greater than a threshold force length and if the length of the sense island is greater than a threshold sense length, then the product of the lengths is calculated, and if greater than a threshold size, designated a valid area. Touch data in the valid area is then acquired in mutual-capacitance sensing mode, and represents palm touch if a maximum strength value in the valid area is less than a maximum area threshold and if a minimum strength value in the valid area is greater than a minimum area threshold.

Abstract: A determination is made as to whether touch pressure data acquired from each of a plurality of touch pressure sensors is indicative of abnormal operation. If abnormal operation is indicated, the touch pressure data from each of the plurality of touch pressure sensors, except those touch pressure sensors having touch pressure data indicative of abnormal operation, is summed. Then, the sum is multiplied by a correction factor to produce a touch pressure output indicative of physical force applied to the plurality of touch pressure sensors.

Abstract: A feedback stage for an integrator circuit is provided. The integrator receives a first input current and a second input current that include respective measurement current components and an offset current component. The integrator integrates the first input current and the second input current and generates a first output voltage and a second output voltage. The feedback stage including a transconductance amplifier detects a difference between the first output voltage and the second output voltage and sinks or sources a first output current and a second output current based on the difference between the first output voltage and the second output voltage. The first output current is additively combined with the first input current and the second output current is additively combined with the second input current to mitigate the offset current component at an input of the integrator.

Abstract: A data frame in a touch capacitive sensing circuit includes both mutual capacitance data and self capacitance data. The mutual capacitance data and self capacitance data of the frame are filtered to define mutual capacitance and self capacitance islands. Centroids of the mutual capacitance and self capacitance islands are calculated and then processed in a weighted mixing operation to produce a hybrid centroid that more accurately locates the coordinates of a detected touch/hover.

Abstract: An electronic device includes a plurality of charge-to-current converters each including a first NMOS transistor having a source coupled to a sense line, a first capacitor between a gate and source of the first NMOS transistor so that a transient component of noise from the sense line is applied to both, a first PMOS transistor having a source coupled to the sense line, a second capacitor between a gate and source of the first PMOS transistor so the transient component of the noise is applied to both, a first current mirror having an input coupled to a drain of the first NMOS transistor and an output coupled to an output for that charge to current converter, and a second current mirror having an input coupled to a drain of the first PMOS transistor and an output coupled to the output for that charge to current converter.

Abstract: A touch screen controller includes driving circuitry coupled to a conductive line through a resistance and drives that conductive line with a driving signal passed through the resistance at a drive frequency. Sensing circuitry is coupled to that conductive line and senses a voltage at that conductive line, the voltage being a function of a capacitance seen by that conductive line. Analog to digital conversion circuitry is coupled to the sensing circuitry and samples the sensed voltage at a sampling frequency to produce samples. Processing circuitry is coupled to the analog to digital conversion circuitry and directly calculates a tangent of a phase shift of the voltage due to the resistance and the capacitance from the samples, and determines a self touch value for that conductive line as a function of the tangent of the phase shift of the voltage.

Abstract: Disclosed herein is a touch screen controller including a driver circuit applying a drive signal to a drive line of a capacitive touch sensing panel. The driver circuit is powered by an accurate supply voltage. A driver supply circuit receives an input supply voltage and outputs the accurate supply voltage. The driver supply circuit includes a clocked comparator comparing a divided version of the accurate supply voltage to a reference voltage and outputting a comparison signal based thereupon. A voltage control circuit (e.g. a charge pump circuit) generates the accurate supply voltage in response to the comparison signal. The clocked comparator and voltage control circuit are both clocked by a driver supply circuit clock.

Abstract: A capacitive touch matrix has first conductive row elements spaced apart from one another, and first row interconnection circuitry electrically connects the first conductive row elements. Second conductive row elements are spaced apart from one another, and second row interconnection circuitry electrically connects the second conductive row elements. First conductive column elements are positioned between two adjacent ones of the first conductive row elements, the first conductive column elements being spaced apart from one another. Second conductive column elements are positioned in a same column as the first conductive column elements and between the two adjacent ones of the first conductive row elements, the second conductive column elements being spaced apart from one another. First column interconnection circuitry electrically connects each first conductive column element, and second column interconnection circuitry electrically connects each conductive column element.

Abstract: A resistive microelectronic fluid sensor implemented as an integrated voltage divider circuit can sense the presence of a fluid within a fluid reservoir, identify the fluid, and monitor fluid temperature or volume. Such a sensor has biomedical, industrial, and consumer product applications. After fluid detection, the fluid can be expelled from the reservoir and replenished with a fresh supply of fluid. A depression at the bottom of the sample reservoir allows a residual fluid to remain undetected so as not to skew the measurements. Electrodes can sense variations in the resistivity of the fluid, indicating a change in the fluid chemical composition, volume, or temperature. Such fluctuations that can be electrically sensed by the voltage divider circuit can be used as a thermal actuator to trigger ejection of all or part of the fluid sample.

Abstract: An oscillator circuit includes a first current generator circuit that generates a current complementary to absolute temperature and a second current generator that generates a current proportional to absolute temperature. A temperature slope control circuit adjusts slopes of the current complementary to absolute temperature and the current proportional to absolute temperature in a complementary fashion and adds the current complementary to absolute temperature to the current proportional to absolute temperature after slope control to produce a temperature independent current. A current control circuit adjusts magnitude of the temperature independent current to produce a magnitude adjusted temperature independent current. A current controlled oscillator generates an output signal as a function of the magnitude adjusted temperature independent current.

Abstract: A device includes a touch and pressure sensitive screen having touch pressure sensors and a controller. The controller acquires touch pressure data from the plurality of touch pressure sensors. For each touch pressure sensor, the controller determines whether the touch pressure data from that touch pressure sensor is indicative of abnormal operation of that touch pressure sensor. Where no abnormal operation is indicated, the controller sums the touch pressure data from each of the touch pressure sensors to produce a touch pressure output. Where abnormal operation is indicated, the controller sums the touch pressure data from each of the touch pressure sensors and multiply the sum by a correction factor to produce the touch pressure output.

Abstract: Disclosed herein is a touch screen controller operable with a touch screen. The touch screen controller includes input circuitry to receive touch data from the touch screen, and processing circuitry. The processing circuitry acquires mutual capacitance touch strength values from the touch screen, determines when the mutual capacitance touch strength values define a pre-validated donut touch pattern, and reads self capacitance touch strength values for lines that are contained within bounds of the pre-validated donut touch pattern. If the self capacitance touch strength values for lines contained within bounds of the pre-validate donut touch pattern contain a singular peak value, the processing circuitry validates the pre-validated donut touch pattern as representing a single touch.