Atmel Corporation

Sony Corporation

Terje Saether

Trond Jarle Pedersen

Steinar Myren

Holger Vogelmann

Armin Prohaska

Gregory Brillant

Carl Olof Fredrik Jonsson

Tajeshwar Singh

Hideyuki Sato

Arne Aas

Gunnar Gangstoe

Morten Werner Lund

In one embodiment, a method includes outputting a first current associated with a first electrode track of a self-capacitance touch sensor. The method also includes outputting a second current associated with a second electrode track of the self-capacitance touch sensor. The method also includes measuring a voltage associated with a difference between the first and second currents and determining a position of an object relative to the self-capacitance touch sensor based on the voltage.

Differential sensing for touch sensors

A method includes driving, by a first driver circuit, a current through an electrode and detecting, by a sensing system, a touch based on a change in capacitance at the electrode. The first driver circuit includes a first operational transconductance amplifier and a first current mirror. A second current mirror is coupled to the sensing system. A first switch is coupled to the first current mirror. A second switch is coupled to the first current mirror and the first operational transconductance amplifier. A third switch is coupled to the first operational transconductance amplifier and the second current mirror. A fourth switch is coupled to the second current mirror. A fifth switch is coupled to the first operational transconductance amplifier. A sixth switch is coupled to the first operational transconductance amplifier. A seventh switch is coupled to the first operational transconductance amplifier, the first current mirror, and the second current mirror.

Touch detection

An apparatus includes a driver circuit and a sensing system. The driver circuit includes an operational transconductance amplifier and a current mirror. The current mirror is coupled to the operational transconductance amplifier. The sensing system is coupled to the first current mirror. The sensing system is operable to detect a touch based on a change in capacitance at an electrode of a plurality of electrodes of a touch sensor.

In one embodiment, an apparatus comprises a pulse driver configured to generate an electrical pulse for transmission to a capacitive touch sensor. The apparatus further comprises a timing circuit configured to hold a first switch closed and a second switch open during a first edge of the electrical pulse, and hold the second switch closed and the first switch open during of a second edge of the electrical pulse. The apparatus further comprises a first capacitor configured to receive a first amount of charge that is indicative of a capacitance of an area of the capacitive touch sensor and a second capacitor configured to discharge a second amount of charge that is indicative of the capacitance of the area of the capacitive touch sensor. The apparatus further comprises a differential output configured to provide a measure of the voltage difference between the first capacitor and second capacitor.

Capacitive touch sensor control unit with sampling capacitors for differential integration

In one embodiment, a method includes applying a drive signal to a first electrode of a sensor to generate an electric field extending at least in part from the first electrode toward a second electrode of the sensor. The electric field includes a first portion and a second portion, and the first portion extends farther away from a plane of the first electrode than the second portion. The method also includes shunting the second portion of the electric field away from the second electrode and receiving a sense signal from the second electrode produced at least in part by the first portion of the electric field. The sense signal indicates whether an object has come within proximity of the sensor.

Position detection of an object within proximity of a touch sensor

A first signal from a first sense line of a touch sensor is received. A second signal from a second of the touch sensor is received. The first signal is inverted. The inverted first signal and the second signal are summed to produce a differential signal. The differential signal is output to a touch sensor controller.

Differential sensing for capacitive touch sensors

A circuit and a method for correcting an offset is provided that includes a current amplifier and an adjusting circuit for correcting an offset of an output current of the current amplifier. Wherein the adjusting circuit has a controlled current source, an output of the controlled current source is connected to the current amplifier for impressing an output current of the controlled current source in the current amplifier, an input of the controlled current source to form a regulation element of a control loop is connected by a first switching device of the adjusting circuit to an output of the current amplifier and to form a holding element is disconnected from the output of the current amplifier by the first switching device. The controlled current source, acting as a regulation element in the control loop, is set up to regulate the offset to a minimum by setting of a current value of the output current, and the controlled current source, acting as a holding element, is set up to hold the current value, associated with the minimum, of the output current.

Circuit and method for adjusting an offset output current for an input current amplifier

One or more heating elements are disposed on a semiconductor substrate proximate a temperature sensitive circuit disposed on the substrate (e.g., bandgap circuit, oscillator). The heater element(s) can be controlled to heat the substrate and elevate the temperature of the circuit to one or more temperature points. One or more temperature measurements can be made at each of the one or more temperature points for calibrating one or more reference values of the circuit (e.g., bandgap voltage).

Calibration of temperature sensitive circuits with heater elements

A level shifter for a microcontroller shifts an input voltage in a first power domain to an output voltage level consistent with a second power domain. The level shifter is enabled to shift the voltages when both power domains are operative.

Level shifter with output latch

A driver circuit for a display device (e.g., an LCD) omits buffers and a resistive ladder and connects the output of a switched regulator directly to a display device through a selector switch. Voltage inputs for the display device can be selectively coupled to the output of the switched regulator using the selector switch. Each voltage input can be coupled to a capacitor that is charged when the corresponding voltage input is coupled to the high voltage output of the switched regulator. In some implementations, bypass switches are connected between the voltage inputs. If the voltage of a given capacitor is too high, the excess voltage can be transferred or otherwise discharged through the bypass switch to another capacitor storing a lower voltage.

Selector switch for direct connection of switched regulator to voltage inputs

A brown out detection circuit includes a sense amplifier for sensing a current level exhibited by a flash cell. Combinatorial logic is coupled to the sense amplifier for identifying a program condition of the flash cell based on the sensed current level, including a brown out condition, in order to provide a warning to avoid potential malfunction from a brown out condition.

Method and circuit for detecting a brown out condition

A battery pack can include one or more battery cells, current blocking transistors and a battery management system. The disclosed implementations handle over-currents drawn from the battery cells that cause unstable operation of the battery management system. The over-currents are handled without causing an undesired drop in voltage output from the battery cells. The disclosed implementations can handle over-currents even if the over-currents cause the battery management system supply voltage to drop below a minimum operating voltage level for a certain period of time. The disclosed implementations use current blocking transistors that can be configured to block current flow and ensure safe operation of the battery cells in cases where the current drawn from the battery cells would be sufficiently high for a sufficiently long period of time to cause damage to the battery cells.

Power surge filtering in over-current and short circuit protection

A circuit can include an oscillator core that outputs, in response to a bias signal, a periodic signal having an oscillation frequency; a bias circuit that, when powered, provides the bias signal (e.g., a voltage) to the oscillator core; and a switching circuit that periodically powers the bias circuit at a second frequency and provides the bias signal to the oscillator core when the bias circuit is not powered. The switching circuit can include a storage element that stores energy when the bias circuit is powered and uses stored energy to provide the bias signal when the bias circuit is not powered. The switching circuit can include a divider circuit that divides the oscillation frequency of the periodic signal to generate a control signal having the second frequency, and the bias circuit can be periodically powered at the second frequency in response to the control signal.

Growing community of inventors

Trondheim, Norway

Terje Saether