Abstract: A noise filter circuit uses open loop signal processing to process the signal that causes the noise and generate a signal to be fed back into the system to cancel noise currents.

Abstract: A controller for a switched mode power converter is disclosed, the switched mode power converter comprising a transformer defining a primary side circuit and a secondary side circuit, the primary side circuit comprising a primary switch, the secondary side circuit comprising a synchronous rectification switch, the controller comprising: a baseline off-set circuit configured to provide a baseline timing off-set between opening the synchronous rectification switch and closing the primary switch; a peak current detector configured to detect a peak negative current in the secondary side circuit; and a feedback circuit configured to add an off-set adaptation to the baseline timing off-set to provide an adapted timing off-set, wherein the feedback circuit is configured to adjust the off-set adaptation to minimize the negative peak current. A switched mode power converter and electronic equipment using such a controller is also disclose, as is a method for controlling a switch mode power converter.

Abstract: A resonant converter circuit comprising a controller having a Vbusdiv-input-terminal configured to receive a Vbusdiv-input-signal; and a Vbus-compensation-network. The Vbus-compensation-network comprising: a Vbus-input-terminal configured to receive a bus-voltage-signal; and a Vbusdiv-output-terminal configured to provide the Vbusdiv-input-signal to the controller; a reference terminal; an AC-impedance-network; connected between the Vbus-input-terminal and the Vbusdiv-output-terminal, wherein the AC-impedance-network is configured to apply an AC transfer function to the received bus voltage signal; a DC-impedance-network connected between the Vbus-input-terminal and the Vbusdiv-output-terminal, wherein the DC-impedance-network is configured to apply a DC transfer function to the received bus voltage signal. The DC transfer function is different to the AC transfer function. The controller is configured to control operation of a resonant converter in accordance with the Vbusdiv-input-signal.

Abstract: A control circuit for a switched-mode power supply having an input side (101) connectable to an electrical power source and an output side (102) connectable to a load.

Abstract: A power factor corrector raises power factor at low loads or high mains voltages by modifying the switch timing or the current received by the power converter. It achieves this by increasing the switch-on time of a control switch during the falling time so that the majority of the switch-on time during a mains period occurs during the falling time, to thereby control the current received by the converter to compensate for current received by the intermediate filter. Some embodiments may employ a feedback system to produce one or more error signals that modify the control signal used to control the operation of the converter. Various embodiments may also include additional stages that limit the compensation range of the error signal.

Abstract: A common mode noise sensor with a single amplification path is disclosed. The common mode noise sensor includes first and second terminals for receiving respective first and second signals from a power supply, an amplifier stage connected to the first and second terminals and having an output and a resistor network connected to the amplifier stage. The resistor network is arranged such that the output of the amplifier stage is configured to provide an output signal in which a differential mode noise in the first and second signals is suppressed in preference to a common mode noise in the first and second signals.

Abstract: A controller for a resonant converter, the resonant converter comprising a first switch and a second switch. The controller configured to: close the first switch to start a half cycle of operation; open the first switch before completion of the half cycle; maintain the first switch and the second switch in an open state in order to define a stop-interval; and end the stop-interval by closing the second switch.

Abstract: A method is disclosed of discharging an input capacitor of a switch mode power supply comprising a power switch and the input capacitor, through the power switch and in response to disconnection of the switch mode power supply from a mains supply, the power switch having a control terminal and main terminals; the method comprising a repeated sequence, the sequence comprising: charging the control terminal to partially close the power switch until a comparator indicates that a capacitor discharge current from the capacitor through the main terminals is equal to a reference signal; and thereafter discharging the control terminal, thereby stopping the capacitor discharge current. A corresponding control and power supply is also disclosed.

Abstract: A control arrangement is disclosed for a switch mode power supply (SMPS) operable in a burst mode and comprising an opto-coupler configured to transfer, from a secondary side to a primary side of the switch mode power supply by means of an LED current, a control signal indicative of a time-varying error between a reference signal and a signal indicative of an actual value of an output parameter, the control arrangement comprising: an error amplifier configured to operate as a proportional-integrating error amplifier to determine the LED current from the time-varying; and a feedback loop configured to adjust the magnitude of the LED current between bursts by modifying the time-dependant error. A SMPS comprising such a control arrangement, and a corresponding method is also disclosed.

Abstract: The present invention relates to a noise sensor for an alternating or direct current power supply. The sensor comprises a noise sensing unit and a noise separator. The noise separator is configured to receive first, second and third input signals and provide a first output signal representative of the common mode noise and a second output signal representative of the differential mode noise. The noise sensing unit comprises a first capacitive element, a second capacitive element, a first resistive element and a second resistive element.

Abstract: The disclosure relates to a control arrangement for a SMPS, the control arrangement comprising: an input terminal configured to receive a feedback-signal (V1) representative of an output of the SMPS; a normal-mode-processing-arrangement-configured to process the feedback-signal and provide a normal-mode-control-signal for operating the SMPS in a normal mode of operation; a burst-mode-processing-arrangement configured to process the feedback-signal and provide a burst-mode-control-signal for operating the SMPS in a burst mode of operation; and a feedback-control-processing-arrangement configured to operate the SMPS such that the feedback signal in the normal mode of operation has a predetermined relationship with the feedback signal in the burst mode of operation.

Abstract: A noise detection circuit 100 for a power supply, the noise detection circuit 100 comprising: an impedance element 110 connected to a line 104 for carrying a power supply current having a noise signal component, the noise signal comprising a common mode noise signal and a differential mode noise signal; a filter element 112 coupled to the impedance element 110 and configured to suppress the differential mode noise signal in the noise detection circuit 110; and an evaluation circuit 140 coupled to the impedance element 110 or the filter element 112 and arranged to sense the common mode noise signal and provide an output representative of the common mode noise signal.

Abstract: A method is disclosed of controlling a switched mode converter comprising a switch and for providing power to device having a load, comprising: in response to the load exceeding a first threshold, operating in a first mode, being a CCM; in response to the load exceeding a second threshold and not exceeding the first threshold, operating in second mode, being a BCM without valley skipping wherein the switching frequency increases with decreasing load; in response to the load exceeding a third threshold and not exceeding the second threshold, operating in a third mode, being a BCM with valley skipping, wherein the switching frequency depends on the load and the number of valleys skipped and is between a fixed upper and a lower switching frequency limit; and in response to the load not exceeding the third threshold, operating in a fourth mode, being a BCM with valley skipping, wherein the switching frequency depends on at least the load, and is between an upper and a lower switching frequency limit wherein the u

Abstract: Consistent with an example embodiment, the disclosed includes a synchronized logic circuit comprising: an input module; an output module; a decision logic module connected between the input and output modules and configured to provide a next output state to the output module dependent on a current input state provided from the input and output modules; a clock module connected to the input and output modules and configured to provide a clock signal for synchronizing operation of the input and output modules; and an input detection module connected to the input module and configured to provide an enable signal to the clock module on detection of a change in an input provided to the input module, wherein the clock module is configured to provide a clock signal to the input and output modules on receiving the enable signal from the input detection circuit.

Abstract: An example embodiment relates to a switched-mode power supply comprising a transformer with a first winding and a second winding. There is a transmitter configured to: detect a detectable variable (Vout) at the first winding, generate a transformer relayed signal in accordance with the detectable variable (Vout), and provide the transformer relayed signal to the first winding. A receiver is configured to: receive the transformer relayed signal from the second winding, and control a controllable variable at the second winding in response to the transformer relayed signal, wherein the transformer relayed signal is a symbol stream comprising a plurality of symbols.

Abstract: Consistent with an example embodiment, the disclosed includes a synchronised logic circuit comprising: an input module; an output module; a decision logic module connected between the input and output modules and configured to provide a next output state to the output module dependent on a current input state provided from the input and output modules; a clock module connected to the input and output modules and configured to provide a clock signal for synchronising operation of the input and output modules; and an input detection module connected to the input module and configured to provide an enable signal to the clock module on detection of a change in an input provided to the input module, wherein the clock module is configured to provide a clock signal to the input and output modules on receiving the enable signal from the input detection circuit.

Abstract: A controller for a switched mode power converter is disclosed, the switched mode power converter comprising a transformer defining a primary side circuit and a secondary side circuit, the primary side circuit comprising a primary switch, the secondary side circuit comprising a synchronous rectification switch, the controller comprising: a baseline off-set circuit configured to provide a baseline timing off-set between opening the synchronous rectification switch and closing the primary switch; a peak current detector configured to detect a peak negative current in the secondary side circuit; and a feedback circuit configured to add an off-set adaptation to the baseline timing off-set to provide an adapted timing off-set, wherein the feedback circuit is configured to adjust the off-set adaptation to minimise the negative peak current. A switched mode power converter and electronic equipment using such a controller is also disclose, as is a method for controlling a switch mode power converter.

Abstract: The invention relates to methods of controlling operation of a resonant power converter and to controllers configured to operate according to such methods. Embodiments disclosed include a method of controlling a power output of a resonant power converter comprising first and second switches (S1, S2) connected in series between a pair of supply voltage lines, a resonant circuit connected to a node between the first and second switches and to an output connectable to an output electrical load, the resonant circuit comprising an inductor and a capacitor, the method comprising: closing the first switch (S1) to start a first conduction interval; setting a first voltage level (902); setting a first time period; and opening the first switch (S1) to end the first conduction interval when a voltage (901) across the capacitor crosses the first voltage level (902) and when a time period from closing the first switch exceeds the first time period (904).

Abstract: A common mode noise sensor with a single amplification path is disclosed. The common mode noise sensor includes first and second terminals for receiving respective first and second signals from a power supply, an amplifier stage connected to the first and second terminals and having an output and a resistor network connected to the amplifier stage. The resistor network is arranged such that the output of the amplifier stage is configured to provide an output signal in which a differential mode noise in the first and second signals is suppressed in preference to a common mode noise in the first and second signals.

Abstract: Methods for supplying a synchronous rectifier (SR) driver circuit and supply voltage generation circuits for a SR driver circuit are described. In one embodiment, a method for supplying a SR driver circuit involves receiving a converted voltage from a secondary winding of a transformer and generating a supply voltage for the SR driver circuit based on the converted voltage, where the supply voltage is higher than an output voltage of the transformer that is generated using the secondary winding. Other embodiments are also described.