Abstract: A control circuit for use in an isolated power converter includes an output-side first controller having a switch control signal generator and an extremum locator. The switch control signal generator communicates a control signal to a second controller on the input side of the power converter via an isolated interface to initiate a transition of a switch from an OFF state to an ON state. The extremum locator enables the switch control signal generator to communicate the control signal in response to an oscillating voltage signal at an output terminal of the energy transfer element. The extremum locator enables the switch control signal generator such that the transition of the switch from the OFF state to the ON state occurs substantially at a time that the oscillating voltage signal reaches an extremum.

Abstract: A controller for use in a power converter includes a drive circuit coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from a power converter input to a power converter output. An input for receiving an enable signal including enable events is responsive to the power converter output. The drive circuit is coupled to turn ON the power switch in response to the enable events and turn OFF the power switch in response to a power switch current reaching a current limit threshold. A current limit threshold generator is coupled to receive the enable events and vary the current limit threshold in response to the enable events of the enable signal.

Abstract: A system for controlling a light source includes a control circuit to be coupled to an ac source to receive an ac signal. The control circuit includes an input controller coupled to receive an input control signal and dimming command circuitry coupled to the input controller and coupled to receive the ac signal. The dimming command circuitry is coupled to remove one or more portions of a predetermined duration from the ac signal followed by a substantially full ac signal in response to the input control signal. A lighting driver circuit is to be coupled to a light source and coupled to receive the ac signal from the control circuit. The lighting driver circuit is coupled to drive the light source to have a light output adjusted in response to the removed one or more portions of the predetermined duration from the ac signal by the dimming command circuitry.

Abstract: An integrated circuit package for use in a switch mode power converter includes a portion of a lead frame disposed within an encapsulation. The lead frame includes a first conductor having an inner conductive loop disposed within the encapsulation, and a second conductor galvanically isolated from the first conductor having an outer conductive loop disposed within the encapsulation and magnetically coupled to the first conductive loop to provide a communication link between the first and second conductors. First and second control circuits are coupled to the first and second conductors, respectively. The first control circuit is coupled to control a switching circuit in response to one or more control signals communicated between first and second dice that include the first and second control circuits, respectively, through the communication link to regulate a transfer of energy from an input to an output of the switch mode power converter.

Abstract: A controller includes a switching control coupled to switch a power switch of a power converter to regulate an output of the power converter. A sensor is coupled to receive a signal from a single terminal of the controller. The signal from the single terminal is representative of a line input voltage of the power converter during at least a portion of an on time of the power switch, and an output voltage of the power converter during at least a portion of an off time of the power switch. The switching control is responsive to an output of the sensor, and includes a first current source, an internal voltage supply coupled to the first current source, and a buffer circuit coupled to receive the signal from the single terminal. The first current source is coupled to supply a first current to the buffer circuit.

Abstract: A controller for use in a power converter includes a drive circuit coupled to generate a drive signal to control switching of a power switch to control a transfer of energy from a power converter input to a power converter output. The controller also includes an input for receiving an enable signal including enable events responsive to the power converter output. The drive circuit is coupled to turn ON the power switch in response to the enable events and turn OFF the power switch in response to a power switch current reaching a current limit threshold. A current limit threshold generator is coupled to receive the drive signal from the enable events of the enable signal. The current limit threshold may be a ramp signal and the ramp signal along with the time between enable events may be used to modulate the drive signal.

Abstract: A power converter controller includes a primary controller and a secondary controller. The primary controller is coupled to receive one or more request signals from the secondary controller and transition a power switch from an OFF state to an ON state in response to the received request signals. The secondary controller is coupled to transmit the request signals to the primary controller and control the amount of time between the transmission of each of the request signals. The secondary controller includes a timing circuit that sets a minimum amount of time between the transmission of the request signals. The secondary controller also includes a secondary switch control circuit coupled to trigger the timing circuit in response to transmitting a request signal.

Abstract: A power converter controller includes a primary controller coupled to operate in a first mode to control a power switch with a primary switching pattern. A secondary controller is galvanically isolated from the primary controller. The secondary controller is coupled to initiate a transition operation with the primary controller to take control of the power switch with one or more control signals through a communication link. The primary controller is coupled to acknowledge receipt of the one or more control signals to the secondary controller and transition from the first mode to a second mode.

Abstract: An example power supply regulator includes an energy transfer element, a switch, and a controller. The controller includes a switch signal generator, a modulation circuit, and a multi-cycle modulator circuit. The modulation circuit modulates the period of a modulation switching signal when an equivalent switching frequency is greater than a reference frequency and fixes the switching period when the equivalent switching frequency is less than the reference frequency. The multi-cycle modulator circuit enables the switch signal generator to provide a switch signal uninterrupted if the equivalent switching frequency is greater than the reference frequency and disables the switch signal generator for a first time period and then enables the switch signal generator for a second time period when the equivalent frequency is less than the reference frequency. The multi-cycle modulator circuit varies the first time period to regulate the output.

Abstract: A controller for use in a power converter includes a switching control and a sensor. The switching control generates a first signal to control switching of a power switch between a first state and a second state. The sensor receives a second signal from a single terminal of the controller during at least a portion of the time that the power switch is in the first state and during at least a portion of the time that the power switch is in the second state. The second signal is representative of a line input voltage during at least the portion of time that the power switch is in the first state and is representative of an output voltage during at least the portion of time that the power switch is in the second state. The sensor is coupled to be responsive to the first signal.

Abstract: A power converter controller includes a primary controller and a secondary controller. The primary controller is coupled to receive one or more request signals from the secondary controller and transition a power switch from an OFF state to an ON state in response to each of the received request signals. The primary controller is coupled to detect a turn-off condition when the power switch is in the ON state and transition the power switch from the ON state to the OFF state in response to detection of the turn-off condition. The secondary controller is galvanically isolated from the primary controller. The secondary controller is coupled to transmit the request signals to the primary controller and control the amount of time between the transmission of each of the request signals.

Abstract: A voltage comparator includes an amplifier coupled to receive an input signal at an amplifier input and generate an output signal at an amplifier output in response to the input signal. The amplifier includes a current generation circuit coupled to generate a first current flowing through a first branch and a second current flowing through a second branch. A first transistor has a first terminal coupled to the amplifier input and a second terminal coupled to the first branch. A second transistor has a third terminal coupled to the second branch, a fourth terminal coupled to a reference voltage. A second control terminal of the second transistor is coupled to the first control terminal. An output circuit is coupled to the amplifier output to generate a comparator output signal in response to the output signal. The amplifier output is coupled to the second branch.

Abstract: A power converter controller includes a primary controller that is galvanically isolated from a secondary controller. The primary controller controls a state of a power switch during a first mode of operation according to a switching pattern defined by the primary controller. During a second mode of operation, the primary controller controls the state of the power switch in response to control signals received via a communication link. The secondary controller operates in a powered down state during the first mode of operation. The secondary controller initiates a transition operation with the primary controller that transitions the primary controller and the secondary controller from the first mode of operation to the second mode of operation. In the second mode of operation, the secondary controller transmit the control signals to the primary controller via the communication link.

Abstract: A circuit for use in a power converter includes a control circuit coupled to detect whether an electrical energy source is coupled to an input of the power converter. A switch is coupled to the control circuit, and is coupled to transfer energy from the input of the power converter to an output of the power converter during a first operating mode. The control circuit is coupled to drive the switch in the first operating mode when the electrical energy source is coupled to the input of the power converter. The control circuit is coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input of the power converter to drive the switch to discharge a capacitance coupled between input terminals of the power converter to a threshold voltage in less than a maximum period of time.

Abstract: An integrated circuit package includes an encapsulation and a lead frame. A portion of the lead frame is disposed within the encapsulation. The lead frame includes a first conductor forming a first conductive loop. A second conductor is galvanically isolated from the first conductor. The second conductor forms a second conductive loop proximate to and magnetically coupled to the first conductive loop to provide a magnetic communication link between the first and second conductors. A signal that is transmitted from a transmit circuit coupled to the first conductor is coupled to be received through the magnetic communication link by a receive circuit coupled to the second conductor.

Abstract: A secondary control circuit includes a voltage regulator circuit coupled to an output of the power converter to provide a regulated power supply. One or more switched loads are coupled between a first terminal and an output ground terminal. The first terminal is coupled to the output of the power converter. Each switched load is coupled to draw a respective current from a load current to clamp the output of a power converter. One or more comparator circuits are coupled to a second terminal. The second terminal is coupled to receive an output sense signal. Each comparator circuit is coupled to receive a reference signal that is a scaled representation of a first reference signal. Each switched load is switched in response to a respective comparator circuit to draw a respective current from the load current of the power converter to clamp the output of the power converter.

Abstract: A power converter controller includes an input sense circuit to receive an input sense signal representative of an input of a power converter. A zero-crossing detector is coupled to the input sense circuit to be responsive to the input sense signal falling below a first zero-crossing threshold and rising above a second zero-crossing threshold to determine zero-crossing intervals. A timer circuit is coupled to the zero-crossing detector to determine peak intervals and to synchronize an enable signal generated to enable the input sense circuit to sense the input of the power converter during the peak intervals of the input of the power converter. A comparator circuit is coupled to the input sense circuit and the timer circuit to detect if the input of the power converter is greater or less than one or more thresholds during the peak intervals of the input of the power converter.

Abstract: A circuit includes a control circuit coupled to detect whether an electrical energy source is coupled to an input of a power converter. A switch is coupled to the control circuit to transfer energy from the input of the power converter to an output of the power converter during a first operating mode. The control circuit is coupled to drive the switch in the first operating mode when the electrical energy source is coupled to the input of the power converter. The control circuit is coupled to drive the switch in a second operating mode when the electrical energy source is uncoupled from the input of the power converter. The control circuit is coupled to discharge a capacitance coupled between input terminals of the power converter through the switch to a threshold voltage in less than a maximum period of time in the second operating mode.

Abstract: An integrated circuit package for use in a switch mode power converter includes a portion of a lead frame disposed within an encapsulation. The lead frame includes a first conductor having an inner conductive loop disposed within the encapsulation, and a second conductor galvanically isolated from the first conductor having an outer conductive loop disposed within the encapsulation and magnetically coupled to the first conductive loop to provide a communication link between the first and second conductors. First and second control circuits are coupled to the first and second conductors, respectively. The first control circuit is coupled to control a switching circuit in response to one or more control signals communicated between first and second dice that include the first and second control circuits, respectively, through the communication link to regulate a transfer of energy from an input to an output of the switch mode power converter.

Abstract: An integrated circuit package includes an encapsulation and a lead frame. A portion of the lead frame is disposed within encapsulation. The lead frame includes a first conductor having a first conductive loop disposed substantially within the encapsulation. The lead frame also includes a second conductor that is galvanically isolated from the first conductor. The second conductor includes a second conductive loop that is substantially disposed within the encapsulation proximate to and magnetically coupled to the first conductive loop to provide a communication link between the first and second conductors.