Abstract: A host electronic device may be coupled to an accessory electronic device. During normal operation, the host device may supply the accessory device with power over a power supply line. Back-powering events in which the accessory device delivers power to the host device may be prevented by interposing a protection transistor in the power supply line. A current mirror may be formed using the protection transistor and an additional transistor that produces a sense current proportional to the amount of current that is flowing through the power supply line. A current-to-voltage amplifier may produce a sense voltage that is proportional to the sense current. A bias circuit may be used to bias the sense current through the current mirror. A control circuit may compare the sense voltage to one or more reference voltages and turn off the protection transistor when appropriate to prevent back-powering of the host device.

Abstract: Methods for operating a portable electronic device to conduct a mobile payment transaction at a merchant terminal are provided. The electronic device may verify that the current user of the device is indeed the authorized owner by requiring the current user to enter a passcode. If the user is able to provide the correct passcode, the device is only partly ready to conduct a mobile payment. In order for the user to fully activate the payment function, the user may have to supply a predetermined payment activation input such as a double button press that notifies the device that the user intends to perform a financial transaction in the immediate future. The device may subsequently activate a payment applet for a predetermined period of time during which the user may hold the device within a field of the merchant terminal to complete a near field communications based mobile payment transaction.

Abstract: A host electronic device may be coupled to an accessory electronic device. During normal operation, the host device may supply the accessory device with power over a power supply line. Back-powering events in which the accessory device delivers power to the host device may be prevented by interposing a protection transistor in the power supply line. A current mirror may be formed using the protection transistor and an additional transistor that produces a sense current proportional to the amount of current that is flowing through the power supply line. A current-to-voltage amplifier may produce a sense voltage that is proportional to the sense current. A bias circuit may be used to bias the sense current through the current mirror. A control circuit may compare the sense voltage to one or more reference voltages and turn off the protection transistor when appropriate to prevent back-powering of the host device.

Abstract: Methods for operating a portable electronic device to conduct a mobile payment transaction at a merchant terminal are provided. The electronic device may verify that the current user of the device is indeed the authorized owner by requiring the current user to enter a passcode. If the user is able to provide the correct passcode, the device is only partly ready to conduct a mobile payment. In order for the user to fully activate the payment function, the user may have to supply a predetermined payment activation input such as a double button press that notifies the device that the user intends to perform a financial transaction in the immediate future. The device may subsequently activate a payment applet for a predetermined period of time during which the user may hold the device within a field of the merchant terminal to complete a near field communications based mobile payment transaction.

Abstract: Examples of the disclosure are directed to methods of managing power of various modules of an electronic device to prevent the voltage of the battery from falling to an undervoltage lockout (UVLO) threshold. In some examples, software operating on the electronic device or an associated electronic device (e.g., a paired electronic device) may assign power budgets to one or more modules, thereby preventing each module from drawing its maximum current capacity and causing the battery's voltage level to fall to the UVLO threshold. In some examples, a pre-UVLO threshold (i.e., a threshold higher than the UVLO threshold) may be used to modify the states of one or more modules to save power as the voltage of the battery approaches the UVLO threshold, but before the device must be fully powered off.

Abstract: An inductor coil includes a wire which is wound in alternating layers such that the surface area of the wire in each winding viewed from above or below the coil is substantially equal in each half of the coil defined by a line bisecting the center point in each layer. The layers are also wound in a serpentine fashion to balance the capacitance between layers. The substantially equal surface area of wire in each half of a coil layer and in adjacent coil layers results in a balanced capacitance of the coil which, in turn, results in reduced common mode noise.

Abstract: Methods for operating a portable electronic device to conduct a mobile payment transaction at a merchant terminal are provided. The electronic device may verify that the current user of the device is indeed the authorized owner by requiring the current user to enter a passcode. If the user is able to provide the correct passcode, the device is only partly ready to conduct a mobile payment. In order for the user to fully activate the payment function, the user may have to supply a predetermined payment activation input such as a double button press that notifies the device that the user intends to perform a financial transaction in the immediate future. The device may subsequently activate a payment applet for a predetermined period of time during which the user may hold the device within a field of the merchant terminal to complete a near field communications based mobile payment transaction.

Abstract: A transmitter device for an inductive energy transfer system can include a DC-to-AC converter operably connected to a transmitter coil, a first capacitor connected between the transmitter coil and one output terminal of the DC-to-AC converter, and a second capacitor connected between the transmitter coil and another output terminal of the DC-to-AC converter. One or more capacitive shields can be positioned between the transmitter coil and an interface surface of the transmitter device. A receiver device can include a touch sensing device, an AC-to-DC converter operably connected to a receiver coil, a first capacitor connected between the receiver coil and one output terminal of the AC-to-DC converter, and a second capacitor connected between the receiver coil and another output terminal of the AC-to-DC converter. One or more capacitive shields can be positioned between the receiver coil and an interface surface of the receiver device.

Abstract: An electronic device may include protection circuitry coupled to a connector port. The connector port may be a reversible connector port that receives a mating reversible connector plug with either first or second orientations. The connector port may include contacts for receiving and/or transmitting signals during communications between the electronic device and the accessory device. The protection circuitry may monitor signals received at the contacts to determine whether transient or permanent connection faults exist. In response to determining that a connection fault exists at any of the contacts, the protection circuitry may electrically disconnect the faulty contacts from processing circuitry in the electronic device.

Abstract: Techniques for detecting mating and un-mating of a first connector with a second connector include providing a pulsed voltage signal at a contact of the second connector and measuring a rate of rise of voltage at the contact. If the measured voltage at the contact exceeds a threshold voltage during the time the pulsed voltage signal is applied, then it is concluded that the first connector is not present and not mated with the second connector. If the measured voltage is lower than or equal to the threshold voltage during the time of application of the voltage pulse, it is concluded that the first connector is present and mated with the second connector.

Abstract: A vibrator designed to be integrated into a portable electronic device as part of a haptic alert device has a linear electric motor that is coupled to actively drive a moveable weight in back-and-forth directions to produce the desired vibration. A lock mechanism has a restraining member that is biased into a lock position, which prevents the moveable weight from moving in the back-and-forth directions when the vibrator is inactive. Other embodiments are also described and claimed.

Abstract: Techniques for detecting mating and un-mating of a first connector with a second connector include providing a pulsed voltage signal at a contact of the second connector and measuring a rate of rise of voltage at the contact. If the measured voltage at the contact exceeds a threshold voltage during the time the pulsed voltage signal is applied, then it is concluded that the first connector is not present and not mated with the second connector. If the measured voltage is lower than or equal to the threshold voltage during the time of application of the voltage pulse, it is concluded that the first connector is present and mated with the second connector.

Abstract: An electronic device may include protection circuitry coupled to a connector port. The connector port may be a reversible connector port that receives a mating reversible connector plug with either first or second orientations. The connector port may include contacts for receiving and/or transmitting signals during communications between the electronic device and the accessory device. The protection circuitry may monitor signals received at the contacts to determine whether transient or permanent connection faults exist. In response to determining that a connection fault exists at any of the contacts, the protection circuitry may electrically disconnect the faulty contacts from processing circuitry in the electronic device.

Abstract: Methods and apparatuses related to adaptively tuning vibratory motors are disclosed. One embodiment takes the form of a method of adaptively tuning a vibratory motor including operating the motor at a plurality of voltage levels and recording the frequency of operation of the motor at each of the plurality of voltage levels. The method also includes creating a curve based on the recorded frequency and voltage levels and selecting a drive voltage based upon an intersection of a desired frequency of operation and the created curve.

Abstract: An electronic audio host device has an audio accessory connector with multiple pins. An ultrasonic test signal source has an output coupled to a first pin of the connector. A programmable switch circuit couples a second or third pin of the connector, to a ground of the audio host device. A controller measures a signal on one of the pins of the connector while the test signal source is on, and compares the measured signal to a predetermined, stored signature. The signature is associated with one of several different accessory plug pin assignments for the connector, which can be configured using the programmable switch circuit. Other embodiments are also described and claimed.

Abstract: A host electronic device may be coupled to an accessory electronic device. During normal operation, the host device may supply the accessory device with power over a power supply line. Back-powering events in which the accessory device delivers power to the host device may be prevented by interposing a protection transistor in the power supply line. A current mirror may be formed using the protection transistor and an additional transistor that produces a sense current proportional to the amount of current that is flowing through the power supply line. A current-to-voltage amplifier may produce a sense voltage that is proportional to the sense current. A bias circuit may be used to bias the sense current through the current mirror. A control circuit may compare the sense voltage to one or more reference voltages and turn off the protection transistor when appropriate to prevent back-powering of the host device.

Abstract: A passive filter circuit filters an input signal to attenuate an undesired frequency. The passive filter circuit includes a first stage and a second stage. The input to the first stage is the input signal. The first stage includes a first inductor and a first branch coupled to the output of the first inductor. The first branch includes a first capacitor and a second inductor. The first stage is coupled to the second stage. The second stage includes a third inductor and a second branch coupled to the output of the third inductor. The second branch includes a second capacitor. Other embodiments are also described and claimed.

Abstract: A vibrator designed to be integrated into a portable electronic device as part of a haptic alert device has a linear electric motor that is coupled to actively drive a moveable weight in back-and-forth directions to produce the desired vibration. A lock mechanism has a restraining member that is biased into a lock position, which prevents the moveable weight from moving in the back-and-forth directions when the vibrator is inactive. Other embodiments are also described and claimed.

Abstract: A low Z linear vibrator is described well suited for use in small form factor portable devices such as a smartphone. The low Z vibrator can be configured to include a beam structure that can be attached to a vibratory mass and a low profile actuator. The low profile actuator can cause the vibratory mass to oscillate in a well-defined and predictable manner.

Abstract: An electronic audio host device has an audio accessory connector with multiple pins. An ultrasonic test signal source has an output coupled to a first pin of the connector. A programmable switch circuit couples a second or third pin of the connector, to a ground of the audio host device. A controller measures a signal on one of the pins of the connector while the test signal source is on, and compares the measured signal to a predetermined, stored signature. The signature is associated with one of several different accessory plug pin assignments for the connector, which can be configured using the programmable switch circuit. Other embodiments are also described and claimed.