Cirrus Logic Inc.

Wolfson Microelectronics Limited

Cirrus Logic International Semiconductor Limited

Andrew James Howlett

John Bruce Bowlerwell

David Paul Singleton

Graeme Gordon Mackay

Douglas James Wallace MacFarlane

John Paul Lesso

Robert David Rand

Gordon Russell

Sharjeel Riaz

Aniruddha Satoskar

Kapil Sharma

Andrew Buist

Louis Frew

Simon Kenneth Quinn

Saurabh Singh

Graeme S Angus

Andrei Dumitriu

An integrated circuit (IC), comprising: a converter comprising: one or more core devices; and one or more output internal nodes, each internal node coupled to one of the one or more core devices; protection circuitry comprising: one or more isolation switches, each of the one or more isolation switches coupled between a respective one of the one or more internal output nodes and a respective output external pin of the IC, wherein the protection circuitry configured to: monitor a characteristic at each respective external output pin of the IC; and if the characteristic is outside an operating specification of the one or more core devices, open one or more of the one or more isolation switches to isolate one or more of the one or more core devices from the respective external pin of the IC.

Protection circuitry

The present disclosure relates to circuitry comprising audio amplifier circuitry for receiving an audio signal to be amplified; and first and second output nodes for outputting first and second differential output signals. The circuitry further comprises common mode buffer circuitry configured to receive a common mode voltage and to selectively output the common mode voltage to the first and second output nodes.

Audio amplifier circuitry

The present disclosure relates to circuitry for providing an output voltage. The circuitry comprises: voltage generator circuitry configured to provide an output voltage to an output node of the circuitry; current limiter circuitry operable to perform current limiting so as to limit a current supplied at the output node of the circuitry; detection circuitry configured to output a detection signal when a load voltage across a load coupled to the output node of the circuitry reaches a target voltage; and delay circuitry configured to receive the detection signal and to output a control signal to deactivate current limiting by the current limiter circuitry after a predetermined delay period after receiving the detection signal.

Circuitry for providing an output voltage

This application relates to monitoring of electronic devices () and in particular to methods and apparatus for the detection and recording of an electrical overstress applied to a connector () of the device. The apparatus describes an integrated circuit () of the host device having a first set of one or more circuit contacts () for connection to a connector () of a host electronic device. The circuit has an electrical overstress monitor () for detecting and recording an electrical overstress comprising a voltage exceeding a predetermined parameter applied to at least one of said first set of circuit contacts. The electrical overstress monitor () may have an overvoltage detector () and may have a memory () for recording the occurrence of an overvoltage and/or a communication module () for communicating with other components of the host device in the event of an electrical overstress.

Monitoring of devices

This application relates to methods and apparatus for transfer of data between a host device () and a peripheral device () via a USB Type-C connector () of the host device. A data controller is described that has a path controller () for establishing signal paths between circuitry of the host device and contacts () of said USB Type-C connector. The path controller is operable in at least first and second modes. In the first mode the path controller establishes separate signal paths to each of at least first, second, third and fourth contacts (A, A, B, B) of the USB Type-C connector and a plurality of the established signal paths are for transfer of analogue audio data. In the second mode the path controller establishes a pair of signal paths to only a subset of said first to fourth contacts to provide a differential digital data path.

Connectors for audio data transfer

This application relates to ADC circuitry. An ADC circuit () has first and second conversion paths () for converting analogue signals to digital and is operable in first and second modes. In the first mode, the first and second conversion paths are connected to respective first and second input nodes () to receive and convert full scale first and second analogue input signals (Ain, Ain) to separate digital outputs (Dout, Dout). In the second mode, the first and second conversion paths are both connected to the first input node (), to convert the first analogue input signal (Ain) to respective first and second digital signals, and the first and second conversion paths are configured for processing different signal levels of the first analogue input signal. A selector () select the first digital signal or the second digital to be output as an output signal based on an indication of amplitude of the first analogue input signal.

ADC circuitry

The present disclosure relates to circuitry for selecting a bias voltage to output at a bias voltage output node of the circuitry. The circuitry comprises a first circuit node configured to receive a first voltage from a first, unregulated, voltage source and a second circuit node configured to receive a second voltage from a second, regulated, voltage source. A switch arrangement configured to selectively couple the bias voltage output node to the first circuit node or the second circuit node is also provided.

Biasing circuitry

This application relates to driver circuitry () for receiving a digital input signal (D) and outputting, at first and second output nodes (), first and second analogue driving signals respectively for driving a transducer (), e.g. loudspeaker, in a bridge-tied-load configuration. The driver circuitry may particularly be suitable for driving low-impedance transducers. The driver circuitry has first and second digital-to-analogue converters () configured to receive the digital input signal and the outputs of the first and second digital-to-analogue converters are coupled to the first and second output nodes respectively. A differential-output amplifier circuit () has outputs connected to the first and second output nodes and is configured to regulate the outputs of the digital-to-analogue converters at output nodes to provide the analogue driving signals.

Driver circuitry

This application relates to amplifier circuitry and, in particular, to class-D amplifier circuits. The application describes amplifier circuitry () for receiving an input signal (Sin) and generating first and second driving signals (SoutP, SoutN) for driving a bridge-tied-load. The amplifier circuitry includes first and second class-D output stages () for generating the first and second driving signals based on the input signal. A controller () controllably varies a common-mode component of the first and second driving signals based on an indication of amplitude of the first and second driving signals. The controller varies the common-mode component, at lower signal amplitudes, so the common-mode level of the first and second driving signals is moved away from an operating region that leads to distortion.

Amplifier circuits

This application relates to monitoring of electronic devices () and in particular to methods and apparatus for the detection and recording of an electrical overstress applied to a connector () of the device. The apparatus describes an integrated circuit integrated circuit () of the host device having a first set of one or more circuit contacts () for connection to a connector () of a host electronic device. The circuit has an electrical overstress monitor () for detecting and recording an electrical overstress comprising a voltage exceeding a predetermined parameter applied to at least one of said first set of circuit contacts. The electrical overstress monitor () may have an overvoltage detector () and may have a memory () for recording the occurrence of an overvoltage and/or a communication module () for communicating with other components of the host device in the event of an electrical overstress.

This application relates to methods and apparatus for monitoring the operating state of an audio circuit, and in particular for detecting a defective operating state, as may occur after an Electrical Over-Stress (EOS) event. An audio circuit () has an input node () for receiving an input audio signal (S) and an output node () for outputting an output audio signal (A) for driving an audio load. A monitoring module () receives a first signal (S) derived from the output audio signal and a second signal (S) indicative of the input audio signal. The monitoring module () monitors the first signal (S) with respect to the second signal (S) to determine whether at least one parameter of the first signal corresponds to an expected parameter value based on the indication of input audio signal. If the parameter does not correspond to the expected parameter value, the monitoring module () outputs an indication (CTRL) of a defective operating state of the audio circuit ().

Audio circuitry

This application relates to analog-to-digital converter (ADC) circuitry (). A time-encoding modulator (TEM) has a comparator () and a loop filter () configured to generate a pulse-width-modulated (PWM) signal (S) in response to an input signal (S) and a feedback signal (S). A controlled oscillator, such as a VCO () receives the PWM signal and generates an output oscillation signal (S) with a frequency that varies based on a drive signal at a drive node (), e.g. a drive node of a ring oscillator (). The controlled oscillator () comprises at least one control switch () controlled by a switch control signal (S) generated from the received PWM signal so as to control the drive strength of the drive signal applied to the drive node (). The feedback signal (S) for the TEM () is derived from the controlled oscillator () so as to include any timing error between the PWM signal and the switch control signal (S) applied to said control switch.

Modulators

This application relates to methods and apparatus for transfer of data between a host device () and a peripheral device () via a USB Type-C connector () of the host device. A data controller is described that has a path controller () for establishing signal paths between circuitry of the host device and contacts () of said USB Type-C connector. The path controller is operable in at least first and second modes. In the first mode the path controller establishes separate signal paths to each of at least first, second, third and fourth contacts (A, A, B, B) of the USB Type-C connector and a plurality of the established signal paths are for transfer of analog audio data. In the second mode the path controller establishes a pair of signal paths to only a subset of said first to fourth contacts to provide a differential digital data path.

A host device for use with a removable peripheral apparatus having a microphone, and to the biasing circuitry for said microphone. The host device may have a device connector for forming a mating connection with a respective peripheral connector. A source of bias is arranged to supply an electrical bias to a device microphone contact of the device connector via a biasing path. A capacitor is connected between a reference voltage node and a capacitor node of the biasing path. A first switch is located between the capacitor node and the device microphone contact. Detection circuitry detects disconnection of the peripheral connector and device connector; and control circuitry controls the switch to disable the biasing path.

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Edinburgh, United Kingdom

Andrew James Howlett