Abstract: Analogue-to-digital converter, ADC, circuitry comprising: successive-approximation circuitry configured in a subconversion operation to draw a charge from a first voltage reference, REF1; compensation circuitry comprising at least one compensation capacitor and configured, in a precharge operation prior to the subconversion operation, to connect the at least one compensation capacitor so that the at least one compensation capacitor stores a compensation charge, and, in the subconversion operation, to connect the at least one compensation capacitor to the first voltage reference so that a charge is injected into the first voltage reference, REF1; and control circuitry, wherein: the successive-approximation circuitry and the compensation circuitry are configured such that one or more parameters defining at least one of said charges are controllable; and the control circuitry is configured to adjust at least one said parameter to adjust an extent to which the charge injected into the first voltage reference, REF

Abstract: Mixed-signal circuitry including a set of capacitive digital-to-analogue converter, CDAC, units for carrying out digital-to-analogue conversion operations to convert respective digital values into corresponding analogue values; and control circuitry, where: each CDAC unit includes an array of capacitors at least some of which are configured to be individually-switched dependent on the digital values, the capacitors configured to have nominal capacitances; a given capacitor of the array of capacitors in each of the CDAC units is a target capacitor; the set of CDAC units includes a plurality of sub-sets of CDAC units; at least one of the target capacitors per sub-set of CDAC units is a variable capacitor, controllable by the control circuitry to have any one of a plurality of nominal capacitances defined by the configuration of that capacitor.

Abstract: Analogue-to-digital converter, ADC, circuitry, including: an analogue input terminal; a comparator having first and second comparator-input terminals; and successive-approximation control circuitry to apply a potential difference across the first and second comparator-input terminals based on an input voltage signal, and to control the potential difference for a series of successive approximation operations to cause the comparator to test in each successive approximation operation whether a magnitude of an analogue input voltage signal is larger or smaller than a corresponding test value, the test value for each successive approximation operation being, dependent on a comparison result generated by the comparator in the preceding approximation operation, bigger or smaller than the test value for the preceding approximation operation by a difference amount configured for that successive approximation operation.

Abstract: In a novel aspect, producing a reference bandgap voltage includes generating a proportional to absolute temperature (PTAT) voltage difference based on respective voltages across a first pair of diodes. The PTAT voltage difference is sampled and scaled using a switched-capacitor amplifier. The switched-capacitor amplifier also is used to sample and scale a difference in voltages across a second pair of diodes, one of which is biased with a PTAT current and the other of which is biased with a current that exhibits little or no linear temperature dependency. The scaled voltage differences are combined with a voltage corresponding to a voltage across the diode that is biased with the PTAT current so as to at least partially compensate for linear and non-linear temperature-dependent components of the voltage across the diode.

Abstract: In a novel aspect, producing a reference bandgap voltage includes generating a proportional to absolute temperature (PTAT) voltage difference based on respective voltages across a first pair of diodes. The PTAT voltage difference is sampled and scaled using a switched-capacitor amplifier. The switched-capacitor amplifier also is used to sample and scale a difference in voltages across a second pair of diodes, one of which is biased with a PTAT current and the other of which is biased with a current that exhibits little or no linear temperature dependency. The scaled voltage differences are combined with a voltage corresponding to a voltage across the diode that is biased with the PTAT current so as to at least partially compensate for linear and non-linear temperature-dependent components of the voltage across the diode.

Abstract: This invention relates to switch mode power supply (SMPS) controllers employing primary side sensing. We describe an (SMPS) controller which uses an area correlator to compare an area under a feedback signal waveform between a start point defined by said first timing signal and an end point defined by said second timing signal with a reference area. An output of the area correlator provides an error signal for regulating the SMPS output.

Abstract: This invention relates to SMPS controllers employing primary side sensing to detect a point of zero magnetic flux, at which the output voltage of the SMPS may be sampled accurately on the primary side. We describe a switch mode power supply (SMPS) controller for regulating the output voltage of an SMPS is response to a feedback signal from an auxilliary winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the SMPS controller comprising: a reference level input to receive an output reference level signal; an input to receive said feedback signal, said feedback signal being responsive to a voltage on said auxilliary winding of said magnetic energy storage device; an integrator to integrate a difference between said feedback signal and a first fixed reference level signal; a first comparator to compare an output of said integrator with a second fixed reference level signal and to provide an output responsive to said comparison for regulating said SMPS output voltage.

Abstract: This invention relates to switch mode power supply (SMPS) controllers employing primary side sensing. We describe an (SMPS) controller which uses an area correlator to compare an area under a feedback signal waveform between a start point defined by said first timing signal and an end point defined by said second timing signal with a reference area. An output of the area correlator provides an error signal for regulating the SMPS output.

Abstract: This invention relates to SMPS controllers employing primary side sensing to detect a point of zero magnetic flux, at which the output voltage of the SMPS may be sampled accurately on the primary side. We describe a switch mode power supply (SMPS) controller for regulating the output voltage of an SMPS is response to a feedback signal from an auxilliary winding of a magnetic energy storage device forming part of an output circuit of the SMPS, the SMPS controller comprising: a reference level input to receive an output reference level signal; an input to receive said feedback signal, said feedback signal being responsive to a voltage on said auxilliary winding of said magnetic energy storage device; an integrator to integrate a difference between said feedback signal and a first fixed reference level signal; a first comparator to compare an output of said integrator with a second fixed reference level signal and to provide an output responsive to said comparison for regulating said SMPS output voltage.

Abstract: This invention relates to Switch Mode Power Supply (SMPS) controllers, especially analogue controllers employing a combination of Pulse Width Modulation (PWM) and Pulse Frequency Modulation (PFM). We describe a switch mode power supply (SMPS) controller circuit for controlling a power switching device of said SMPS, the circuit including: a current input to receive a feedback signal current dependent upon an output voltage of said SMPS; a ramp generator circuit coupled to said current control input to generate responsive to said feedback current signal consecutive first and second voltage ramps, one rising the other falling; and a control output responsive to said voltage ramps from said voltage ramp generator to provide a drive signal for controlling said power switching device.