Wolfson Microelectronics Limited

Cirrus Logic Inc.

Ams Ag

Austriamicrosystems Ag

Cirrus Logic International Semiconductor Limited

Holger Haiplik

John Bruce Bowlerwell

Mark McCloy-Stevens

David Dearn

Douglas James Wallace MacFarlane

Andrew Notman

Alastair Mark Boomer

Malcolm Blyth

Grant M More

Ross Crawford Morgan

Jonathan Taylor

Thomas Jessenig

Manfred Lueger

Tahir Rashid

Clive Robert Graham

Abhay Kejriwal

Tobias Bühler

Douglas Macfarlane

Tobias Buehler

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

The present disclosure relates to circuitry comprising: pulse-width modulation (PWM) circuitry configured to generate a PWM output signal; and monitoring circuitry configured to monitor a supply voltage to the PWM circuitry and to output a control signal for controlling operation of the PWM circuitry, wherein the control signal is based on the supply voltage.

PWM circuitry

Methods and apparatus for control of DC-DC converters, especially in valley current mode. The DC-DC converter is operable so that a low side supply switch may be turned off, before the high side supply switch is turned on. During the period when both switches are off the current loop control remains active and the change in inductor (L) current is emulated. One embodiment uses a current sensor for lossless current sensing and emulates the change in inductor current by holding the value of the output of the current sensor (ISNS) at the time that the low side switch turns off and adding an emulated ramp signal (VISLP) until the inductor current reaches zero. Embodiment employing a pulse-skip mode of operation based on a minimum conduction time are also disclosed. The invention enables a seamless transition from Continuous Conduction Mode the Discontinuous Conduction Mode and Pulse Skipping and provide converters that are efficient at low current loads.

DC-DC converters operable in a discontinuous switching mode

Power management integrated circuits (PMICs) and related methods. In one aspect a PMIC which is operable to provide a plurality of PMIC power states is arranged to provide a predetermined delay before a power state transition. The delay is applied after receipt by the PMIC control circuitry of a power state transition command. Applying a delay allows time for the system powered by the PMIC to perform any necessary shut-down procedures and terminate active processes before power is removed, preventing corruption of the system. The delay is preferably configurable. The PMIC may also be arranged to control power converters which are external to the PMIC. In another aspect the PMIC has translation circuitry for providing the control settings of one power block, e.g. power converter, with any necessary modifications to be used by another power block. This means that only one set of control settings needs to be updated to change the output of both power blocks simultaneously.

Power management apparatus and methods

Apparatus and method for power management and especially to power management integrated circuits (PMICs). In one aspect, the invention relates to a PMIC having an internal non-volatile memory (NVM) for storing boot settings for the PMIC. The PMIC also has control circuitry for detecting whether a source of boot settings is available, such as an NVM external to the PMIC, and, if so, using any settings stored in the external source in preference to the relevant settings stored in the internal NVM. The external settings can thus override any internal settings, which is useful for fault diagnosis and/or development. In one aspect the PMIC may have programming circuitry for automatically programming boot settings from an external source into the internal NVM.

An apparatus and a method for charging and for charge monitoring of a rechargeable battery. A charging circuit contains a rechargeable battery (B) and a charging device (L) for charging the rechargeable battery. A measurement device (M) is arranged in the charging circuit and contains a device for determining the rechargeable-battery current and the state of charge of the rechargeable battery. A control device (R) compares a value that is proportional to the rechargeable-battery current with a set value, and controls the charging device.

Device and method for charging and controlling the charge of a battery

A converter including an inductor (L), a first switch (SW, S) connected between an input terminal (V) and the inductor, a diode/switch (D, S), connected between the first end of the inductor and ground, a diode/switch (D, S) connected between the inductor and an output terminal (V), and a second switch (SW, S) coupled between inductor and ground. A current sensor senses current in the first switch (SW, S) as a measure of inductor current. Waveform generators () generate buck and boost slope compensation ramps (RMP-BUCK, RMP-BOOST). Control logic () opens and closes the switches every clock period at individual duty cycles determined using a feedback signal derived from the output terminal, the sensed current and the slope compensation ramps. The slope compensation ramps are mutually offset such that current sensing is needed only while the first switch (SW, S) is closed.

Constant frequency current-mode buck-boost converter with reduced current sensing

An integrated circuit includes a comparator having a first input, a second input, and an output for providing a comparison result. The first input is connected to a readable component having a predefined value, and the second input is connected to a reference component. A control unit is at the output of the comparator. The control unit controls at least one function block based on the comparison result.

Integrated circuit arrangement, and method for programming an integrated circuit arrangement

A real time clock comprises a counter which stores a count value, the count value representing a time signal. The counter may be written, for example by a host processor (not shown), such that the time signal can be set to any desired value. The real time clock comprises a check register that stores a check value. The content of the check register (i.e. the check value) is modified each time a write operation is performed on the counter. For example, the content of the check register can be updated by a control signal each time a write operation is performed on the counter. The check value stored in the check register is used for determining whether a write operation performed on the counter is an authorized write operation or an unauthorized write operation. The check value may be incremented each time a write operation is performed, replaced with a new random number each time a write operation is performed, or a combination of both.

Real time clock

A reliable start-up circuit for starting a bandgap type voltage reference generator which ensures that the bandgap reference cell will operate at a stable operating point before the start-up circuit is disabled.

Voltage reference circuit

A current-mode switching regulator including at least: an inductor; a main switch for controlling the current flow through the inductor; and a feedback control circuit for operating the main switch cyclically and to vary a duty cycle of the main switch so as to substantially maintain an output voltage of the regulator at a desired level. The feedback control circuit further includes slope compensation circuitry adding slope compensation to a signal representing the inductor current prior to the slope compensated signal being compared to the fed-back output error voltage. The regulator further includes current limiting circuitry for controlling the main switch responsive to a current limit reference signal, the current limit circuitry including adjustment circuitry for adjusting the current limit reference signal in response to the duty cycle of more than one previous cycle so as to limit current in the inductor irrespective of the output voltage and to a value which, in the steady state, is substantially independent of the duty cycle.

Switching regulator circuits

A current sensing circuit for sensing the current through a main switch, such as the PMOS or NMOS switches of a switching regulator, is disclosed. The circuit includes a mirror switch, said mirror switch being substantially similar to said main switch but with a smaller aspect ratio, a difference amplifier for ensuring that the voltage across said first leg and across said second leg are substantially equal and thereby to derive from said mirror switch a sensing current nominally equal to a current flowing in said main switch divided by a sensing ratio, a current source for producing a quiescent current in said difference amplifier and a compensatory device for compensating for said quiescent current such that said current sensing circuit can sense currents in the main switch which are smaller than the quiescent current multiplied by the sensing ratio. The compensatory device may be one or two switches essentially similar to the mirror switch.

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Swindon, United Kingdom

Holger Haiplik