Abstract: An electronic device includes a display and a sensor underneath the display. The display has a full pixel density region and a reduced pixel density region. Compared to pixels in the full pixel density region, pixels in the reduced pixel density region can be controlled using overdriven power supply voltages, overdriven scan control signals, different initialization and reset voltages, and can include capacitors and transistors with different physical and electrical characteristics. Gate drivers provide scan signals to pixels in the full pixel density region, whereas overdrive buffers provide overdrive scan signals to pixels in the reduced pixel density region. The pixels in the full pixel density region and the pixels in the reduced pixel density region can be controlled using different black level or gamma settings for each color channel and can be adjusted physically to match luminance, color, as well as to mitigate differences in temperature and aging impact.

Abstract: An apparatus may include a sense resistor comprising a plurality of parallel-coupled resistor elements, a plurality of positive voltage sense points, and a plurality of negative voltage sense points. A first passive combination network may be configured to combine the plurality of positive voltage sense points into a single positive sense terminal and a second passive combination network may be configured to combine the plurality of negative voltage sense points into a single negative sense terminal. The first passive combination network and the second passive combination network may be arranged such that a sense voltage is measurable between the single positive sense terminal and the single negative sense terminal and a dependence of the sense voltage on a variation in current density in the parallel-coupled resistor elements is minimized.

Abstract: An apparatus may include a sense resistor comprising a plurality of parallel-coupled resistor elements, a plurality of positive voltage sense points, and a plurality of negative voltage sense points. A first passive combination network may be configured to combine the plurality of positive voltage sense points into a single positive sense terminal and a second passive combination network may be configured to combine the plurality of negative voltage sense points into a single negative sense terminal. The first passive combination network and the second passive combination network may be arranged such that a sense voltage is measurable between the single positive sense terminal and the single negative sense terminal and a dependence of the sense voltage on a variation in current density in the parallel-coupled resistor elements is minimized.

Abstract: Systems, methods and apparatus for configuring a fingerprint sensor to operate in a capacitive sensing mode and an ultrasonic sensing mode are disclosed. A fingerprint sensor may be configured to operate in a capacitive sensing mode by driving a sensing electrode using a controller. In some implementations, an object positioned on or near the sensing electrode may be detected using the fingerprint sensor in the capacitive sensing mode, and the controller can drive electrodes of the fingerprint sensor differently to configure the fingerprint sensor to operate in an ultrasonic sensing mode. In some implementations, an applications processor may be instructed to authenticate a fingerprint of the object from image data obtained when the fingerprint sensor is operating in the ultrasonic sensing mode. In some implementations, a display of a mobile device containing the fingerprint sensor may be unlocked, or the mobile device may be woken up when the fingerprint is authenticated.

Abstract: A voltage burst is generated using a voltage supply having a single DC output voltage, VH coupled with a switching arrangement, including an input and a voltage transmitter output (Tx_Out), the input coupled with the output of the voltage supply. A control arrangement coupled with the switching arrangement is configured to operate the switching arrangement so as to provide, at the Tx_Out, a voltage burst that varies between an intermediate voltage, VM, and one or both of VH, and a minimum voltage, VL, where VL<VM<VH.

Abstract: An apparatus and method for efficiently increasing the signal-to-noise ratio of a biometric sampling system by implementing differential-sampling in successive differential-sampling operations and processing the output of the successive differential-sampling operations to create a biometric image. In some cases, the biometric image may be further noise-reduced by subtracting foreground-off and background-off data.

Abstract: The present disclosure describes aspects of a capacitance-to-voltage modulation circuit. In some aspects, the circuit is used in touch sensing. In some aspects, a modulation circuit comprises a first pair of switches having one switch connected between a voltage source and a capacitor, and another switch connected between ground and the input of the circuit. The circuit also includes a second pair of switches having one switch connected between the voltage source and the input of the circuit, and another switch connected between ground and the capacitor. A third pair of the circuit's switches comprise one switch connected between the capacitor and an input of an analog-to-digital converter (ADC) and another switch connected between the input of the circuit and the input of the ADC. The third pair of switches may enable charge sharing of signals modulated by the first and second pairs of switches, a result of which can be used to sense touch input based on capacitance at the input of the circuit.

Abstract: Systems, methods and apparatus for configuring a fingerprint sensor to operate in a capacitive sensing mode and an ultrasonic sensing mode are disclosed. A fingerprint sensor may be configured to operate in a capacitive sensing mode by driving a sensing electrode using a controller. In some implementations, an object positioned on or near the sensing electrode may be detected using the fingerprint sensor in the capacitive sensing mode, and the controller can drive electrodes of the fingerprint sensor differently to configure the fingerprint sensor to operate in an ultrasonic sensing mode. In some implementations, an applications processor may be instructed to authenticate a fingerprint of the object from image data obtained when the fingerprint sensor is operating in the ultrasonic sensing mode. In some implementations, a display of a mobile device containing the fingerprint sensor may be unlocked, or the mobile device may be woken up when the fingerprint is authenticated.

Abstract: Systems, methods and apparatus for configuring a fingerprint sensor to operate in a capacitive sensing mode and an ultrasonic sensing mode are disclosed. A fingerprint sensor may be configured to operate in a capacitive sensing mode by driving a sensing electrode using a controller. In some implementations, an object positioned on or near the sensing electrode may be detected using the fingerprint sensor in the capacitive sensing mode, and the controller can drive electrodes of the fingerprint sensor differently to configure the fingerprint sensor to operate in an ultrasonic sensing mode. In some implementations, an applications processor may be instructed to authenticate a fingerprint of the object from image data obtained when the fingerprint sensor is operating in the ultrasonic sensing mode. In some implementations, a display of a mobile device containing the fingerprint sensor may be unlocked, or the mobile device may be woken up when the fingerprint is authenticated.

Abstract: Systems, methods and apparatus for configuring a fingerprint sensor to operate in a capacitive sensing mode and an ultrasonic sensing mode are disclosed. A fingerprint sensor may be configured to operate in a capacitive sensing mode by driving a sensing electrode using a controller. In some implementations, an object positioned on or near the sensing electrode may be detected using the fingerprint sensor in the capacitive sensing mode, and the controller can drive electrodes of the fingerprint sensor differently to configure the fingerprint sensor to operate in an ultrasonic sensing mode. In some implementations, an applications processor may be instructed to authenticate a fingerprint of the object from image data obtained when the fingerprint sensor is operating in the ultrasonic sensing mode. In some implementations, a display of a mobile device containing the fingerprint sensor may be unlocked, or the mobile device may be woken up when the fingerprint is authenticated.

Abstract: The present disclosure describes aspects of a capacitance-to-voltage modulation circuit. In some aspects, the circuit is used in touch sensing. In some aspects, a modulation circuit comprises a first pair of switches having one switch connected between a voltage source and a capacitor, and another switch connected between ground and the input of the circuit. The circuit also includes a second pair of switches having one switch connected between the voltage source and the input of the circuit, and another switch connected between ground and the capacitor. A third pair of the circuit's switches comprise one switch connected between the capacitor and an input of an analog-to-digital converter (ADC) and another switch connected between the input of the circuit and the input of the ADC. The third pair of switches may enable charge sharing of signals modulated by the first and second pairs of switches, a result of which can used to sense touch input based on capacitance at the input of the circuit.

Abstract: Systems and methods for producing reference voltages are disclosed. An example bandgap reference circuit includes a core bandgap module that produces a bias control for biasing the gate of a transistor to produce a proportional to absolute temperature current. The core bandgap module may use an operational amplifier that uses auto-calibration to reduce its input offset voltage. A trimming module uses the bias control to produce a proportional to absolute temperature current that is combined with a trim current and supplied to a resistor and diode to produce a trimmed bandgap voltage. The trimmed bandgap voltage is buffered to produce a reference voltage output. The trim current may be set based on a room temperature measurement of the reference voltage output.

Abstract: A display device for displaying multiple images includes a first container for adapting a first display unit, a second container for adapting a second display unit, and a computing module for adjusting a first resolution of a first image generated by the first display unit into a second resolution of a second image generated by the second display unit. The second image is larger than that of the first image. Also, each display unit further includes a touch panel thereon so that the user can control the first display unit by contacting one of the touch panels.