Cirrus Logic Inc.

Wolfson Microelectronics Limited

Alastair Mark Boomer

John Bruce Bowlerwell

Willem Zwart

John Paul Lesso

Holger Haiplik

Michael Page

Malcolm Blyth

Erich Paul Zwyssig

Gavin Alexander Waite

Current detection circuitry for generating an average inductor current signal indicative of an average inductor current during an operational cycle of power converter circuitry, the current detection circuitry comprising: circuitry for generating a peak inductor current signal indicative of a peak inductor current during the operational cycle; and circuitry for applying a ripple current estimate signal, indicative of an estimate of half of a ripple current in the power converter circuitry, to the peak inductor current signal to generate the average inductor current signal, wherein the ripple current is equal to a difference between the average inductor current and the peak inductor current.

Current estimation in a power converter

Circuitry for estimating an inductance of an inductor in power converter circuitry, the circuitry comprising: circuitry for generating a peak inductor current signal indicative of a peak inductor current during an operational cycle of the power converter circuitry; circuitry for generating a ripple current estimate signal, indicative of an estimate of a ripple current in the power converter circuitry; and circuitry for applying the ripple current estimate signal to the peak inductor current signal to generate an average inductor current threshold signal indicative of an estimated average inductor current in the power converter circuitry during the operational cycle, wherein the ripple current estimate signal is based on: a duration of a charging phase of operation of the power converter circuitry; a voltage across the inductor; and an inductance value for the inductor; and wherein the circuitry for generating the ripple current estimate signal is operative to select an inductance value for the inductor for which the estimated average inductor current is equal to an actual average inductor current during the operational cycle to generate a value for the actual inductance of the inductor.

Estimation of an inductance in a power converter

Communication circuitry, comprising: N communication nodes being clock-candidate nodes, where N&#x2265;2; N communication units for communication using respective communication protocols, and connected or connectable to receive respective clock signals for communication under their respective communication protocols via respective said clock-candidate nodes; and a control unit configured, in a decision operation, to monitor the clock-candidate nodes and decide which of the communication protocols is in use dependent on at which of the clock-candidate nodes a received clock signal is detected, wherein at least one said communication unit is connected or connectable to receive and/or transmit data under its respective communication protocol via at least one said clock-candidate node other than the clock-candidate node via which that communication unit is to receive its respective clock signal.

Communication circuitry and control circuitry thereof

A method of sending information between first and second modules connected by a signal bus comprises generating a clock signal in the first module, and imposing the clock signal on a first line of the bus. A first pattern of bit values is transmitted from the second module to the first module on a second line of the bus, during first half-periods of each period of said clock signal. A second pattern of bit values is transmitted from the first module to the second module on the second line of the bus, during second half-periods of each period of said clock signal, wherein the second half-periods of each period of said clock signal are different from the first half-periods of each period of said clock signal. Information can then be transmitted from the first module to the second module by altering the second pattern of bit values; and information can be transmitted from the second module to the first module by altering the first pattern of bit values.

Low power bidirectional bus

A calibration circuit and method suitable for black level calibration in image processing, the circuit comprising an analogue gain amplifier, an analogue to digital converter; a correction circuit for receiving a digital signal and providing a digital offset signal; and a digital to analogue converter for receiving said digital offset signal and feeding a corresponding analogue offset signal back to the input of said gain amplifier. The calibration circuit is arranged such that the correction circuit and said digital to analogue converter form a feedback loop applying an offset to said input signal and said correction circuit includes an inverse gain circuit for applying an inverse gain to a signal within said correction circuit prior to said digital to analogue converter. Preferably the inverse gain applied is such that the total loop gain does not deviate too far from unity.

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Edinburgh, United Kingdom

Alastair Mark Boomer