STMICROELECTRONICS ASIA PACIFIC PTE LTD

An electronic device includes a synchronous rectifier and a battery. The synchronous rectifier outputs a charging current to the battery. The electronic device includes rectifier controller that adjusts a resistance of a switch of the rectifier based on a magnitude of the charging current.

A current sensor includes a sense resistor connected between first and second terminals and an amplification-circuit. The amplification-circuit has an amplifier with inputs coupled to the first and second terminals and an output that produces a voltage representative of the input. A first resistor and second resistor are electrically connected to one of the amplifier inputs. The gain of the amplification-circuit is determined by the resistance of the second resistor and the ratio of the sense resistor resistance to the first resistor resistance. The first resistor and sense resistor are in a ratiometric relationship so they experience equal temperature changes during operation and vary equally in resistance with temperature. The sense resistor includes resistive pillars spaced along a conductive path between the first and second terminals, conductive stacks spaced along the same path, and an unbroken metal sheet contacting the resistive pillars. The pillars have greater resistance than the stacks.

An electronic device includes a touch screen for a touch sensitive display carried by a portable housing. The electronic device is configured to operate in a high detection threshold mode to determine whether an object is in contact with the touch sensitive display, and operate in a low detection threshold mode to determine whether the object is adjacent to the touch sensitive display, based on lack of detection of the object being in contact with the touch sensitive display. The electronic device is further configured to determine whether the object s in contact with a peripheral edge of the portable housing by determining whether the object is adjacent opposite sides of the touch sensitive display, based on detection of the object being adjacent to the touch sensitive display.

An embodiment method for operating an electronic device includes transmitting, from a controller, a tearing effect (TE) signal to a touchscreen over a first period of time, the first period of time occurring during a first frame and having a duration that is shorter than a period of the first frame, the TE signal being configured to restrict image data from being displayed on the touchscreen during the first period of time; displaying the first frame of a plurality of frames of the image data on a display of the touchscreen over a second period of time within the period of the first frame other than during the first period of time; and detecting, at the controller, a first touch by performing a first self-sensing scan during the first period of time.

In a DC-DC converter, a layout is designed to enable utilization the conductive trace connecting the converter output node to an output bump at which the load is attached as a sense resistor. The layout forces the output current down into lower metallization levels of an interconnect layer reaching the converter output node before the output current flows up into this conductive trace and out through the output bump. The conductive trace includes resistive pillars connected in parallel or series between the lower metallization levels and a top metallization layer of the conductive trace, with these resistive pillars being substantially greater in resistance than the lower metallization levels and the top metallization layer of the conductive trace.

A regulator voltage verification circuit for an Advanced Driver Assistance System (ADAS) enables testing of voltage regulators in a pixel array. The circuit generates test voltages representing expected black and white pixel values as a function of the regulator's output voltage. The test voltages are selectively passed to an analog-to-digital conversion circuit in a test mode, while pixel outputs are processed in normal mode. A voltage divider connected to the regulator output creates upper and lower test voltages, which are selected by a multiplexer. The test voltages are routed through a digital correlated double sampling switch to a comparator and ripple counter, converting the analog test values to digital data. By comparing the digital output to expected values, the system can detect regulator malfunctions and issue appropriate warnings. The circuit can be implemented across multiple rows of a pixel array, with test results optionally averaged for accuracy.

In accordance with an embodiment, a method of operating a piezoelectric transducer configured to transduce mechanical vibrations into transduced electrical signals at a pair of sensor electrodes includes stimulating a resonant oscillation of the piezoelectric transducer by applying at least one pulse electrical stimulation signal to the pair of sensor electrodes; detecting, at the pair of sensor electrodes, at least one electrical signal resulting from the stimulated resonant oscillation, wherein the at least one electrical signal resulting from the stimulated resonant oscillation oscillates at a resonance frequency of the piezoelectric transducer; measuring a frequency of oscillation of the at least one electrical signal resulting from the stimulated resonant oscillation to obtain a measured resonance frequency of the piezoelectric transducer; and tuning a stopband frequency of a notch filter coupled to the piezoelectric transducer to match the measured resonance frequency of the piezoelectric transducer.

An electronic device includes a pixel array having a plurality of rows with active imaging pixels, and at least one row with test pixels. Each of the test pixels includes a test voltage generation circuit generating a test voltage, a switching circuit receiving the test voltage and an image pixel output signal and passing the test voltage as output when in a test mode, a comparison circuit receiving the output from the switching circuit and an analog to digital conversion signal and asserting a counter reset signal when the output from the switching circuit and the analog to digital conversion signal are equal in voltage, and a counter beginning counting at a beginning of each test cycle within the test mode, stopping counting upon assertion of the counter reset signal, and outputting its count upon stopping counting. The count is proportional to the test voltage when in the test mode.

In accordance with an embodiment, a method of operating a piezoelectric transducer configured to transduce mechanical vibrations into transduced electrical signals at a pair of sensor electrodes includes stimulating a resonant oscillation of the piezoelectric transducer by applying at least one pulse electrical stimulation signal to the pair of sensor electrodes; detecting, at the pair of sensor electrodes, at least one electrical signal resulting from the stimulated resonant oscillation, wherein the at least one electrical signal resulting from the stimulated resonant oscillation oscillates at a resonance frequency of the piezoelectric transducer; measuring a frequency of oscillation of the at least one electrical signal resulting from the stimulated resonant oscillation to obtain a measured resonance frequency of the piezoelectric transducer; and tuning a stopband frequency of a notch filter coupled to the piezoelectric transducer to match the measured resonance frequency of the piezoelectric transducer.

A method includes: displaying, an image on a display by sequentially displaying a plurality of frames of the image, the plurality of frames including a first frame and second frame; performing a first noise sampling scan at a plurality of frequencies at a first time location within a first frame; determining a first frequency from the plurality of frequencies with the lowest noise; performing a first mutual sensing scan at the first frequency; performing, a second noise sampling scan at the plurality of frequencies at a second time location within a second frame of the plurality of frames, the second time location being a different frame location than the first time location; determining a second frequency from the plurality of frequencies with the lowest noise, the second frequency being different from the first frequency; and performing, a second mutual sensing scan at the second frequency.