Abstract: Apparatus and methods for sensing resonant circuit signals to enhance control in a resonant converter are described herein. A buffer circuit coupled in parallel with or across a resonant component (e.g., a transformer) input port avails a buffered primary port signal for use in resonant conversion. The buffered primary port signal is a comprehensive signal including information relating to both input voltage and input power; and it may be used to advantageously enhance switching and power conversion in an inductor-inductor capacitor (LLC) converter. Additionally, the LLC converter uses a sense interface circuit to provide a scaled replica of the buffered primary port signal. In one example the scaled replica can advantageously be used with a secondary side controller to control output power based on the comprehensive information contained within the buffered primary port signal.

Abstract: A controller for use in a power converter that is configured to operate in a plurality of modes including a first mode and a second mode includes a frequency monitor module coupled to measure a signal characteristic of a switch drive signal coupled to control switching of a switches block of the power converter. The frequency monitor module includes a memory coupled to store a measured signal characteristic of the switch drive signal measured during the first mode. The frequency monitor module is coupled to generate a clock signal in response to the measured signal characteristic stored in the memory. The switch drive signal is coupled to be generated in response to the clock signal during the second mode.

Abstract: Apparatus and methods for sensing resonant circuit signals to enhance control in a resonant converter are described herein. A buffer circuit coupled in parallel with or across a resonant component (e.g., a transformer) input port avails a buffered primary port signal for use in resonant conversion. The buffered primary port signal is a comprehensive signal including information relating to both input voltage and input power; and it may be used to advantageously enhance switching and power conversion in an inductor-inductor capacitor (LLC) converter. Additionally, the LLC converter uses a sense interface circuit to provide a scaled replica of the buffered primary port signal. In one example the scaled replica can advantageously be used with a secondary side controller to control output power based on the comprehensive information contained within the buffered primary port signal.

Abstract: Control of a resonant power converter using switch paths during power-up is described herein. During power-up, a first switch path sinks current away from a resonant capacitor while a second switch path sources current to a high-side capacitor. In this way the high-side capacitor may predictably charge to sufficient bootstrap voltage for steady state operation. Additionally, a third switch path may control current to a low-side capacitor.

Abstract: Apparatus and methods for sensing resonant circuit signals to enhance control in a resonant converter are described herein. A buffer circuit coupled in parallel with or across a resonant component (e.g., a transformer) input port avails a buffered primary port signal for use in resonant conversion. The buffered primary port signal is a comprehensive signal including information relating to both input voltage and input power; and it may be used to advantageously enhance switching and power conversion in an inductor-inductor capacitor (LLC) converter. Additionally, the LLC converter uses a sense interface circuit to provide a scaled replica of the buffered primary port signal. In one example the scaled replica can advantageously be used with a secondary side controller to control output power based on the comprehensive information contained within the buffered primary port signal.

Abstract: A controller for use in a power converter that is configured to operate in a plurality of modes including a first mode and a second mode includes a frequency monitor module coupled to measure a signal characteristic of a switch drive signal coupled to control switching of a switches block of the power converter. The frequency monitor module includes a memory coupled to store a measured signal characteristic of the switch drive signal measured during the first mode. The frequency monitor module is coupled to generate a clock signal in response to the measured signal characteristic stored in the memory. The switch drive signal is coupled to be generated in response to the clock signal during the second mode.

Abstract: A controller for use in a power converter that is configured to operate in a plurality of modes including a first mode and a second mode includes a frequency monitor module coupled to measure a signal characteristic of a switch drive signal coupled to control switching of a switches block of the power converter. The frequency monitor module includes a memory coupled to store a measured signal characteristic of the switch drive signal measured during the first mode. The frequency monitor module is coupled to generate a clock signal in response to the measured signal characteristic stored in the memory. The switch drive signal is coupled to be generated in response to the clock signal during the second mode.

Abstract: A controller configured for use in a power converter includes a multiplexer that receives a startup clock signal and a request clock signal. The multiplexer selects the startup signal or the request clock signal to generate a clock signal. A startup clock generates the startup clock signal to control a switching frequency of a primary switching circuit during a startup condition. A request clock generates the request clock signal in response to a request signal to control the switching frequency of the primary switching circuit after the startup condition. A control circuit receives the clock signal to generate a drive signal control the switching frequency of the primary switching circuit. The control circuit selects the startup clock signal during the startup condition. The control circuit receives an indication in the request signal of an end of an undervoltage condition and then selects the request clock signal after the startup condition.

Abstract: A method to control a high side switch of a motor drive includes sinking a current of an ON signal to communicate a turn ON of the high side switch. A first current signal, a second current signal, a third current signal, a fourth current signal and a common mode rejection signal are generated in response to the ON signal. The ON signal in a presence of common mode noise is determined by comparing the first current signal and the second current signal. A first output signal is generated in response to determining the ON signal. A drive signal is generated responsive to the first output signal to control the high side switch in response to the ON signal in presence of common mode noise that is caused by a slewing at a half-bridge node.

Abstract: Apparatus and methods for sensing resonant circuit signals to enhance control in a resonant converter are described herein. A buffer circuit coupled in parallel with or across a resonant component (e.g., a transformer) input port avails a buffered primary port signal for use in resonant conversion. The buffered primary port signal is a comprehensive signal including information relating to both input voltage and input power; and it may be used to advantageously enhance switching and power conversion in an inductor-inductor capacitor (LLC) converter. Additionally, the LLC converter uses a sense interface circuit to provide a scaled replica of the buffered primary port signal. In one example the scaled replica can advantageously be used with a secondary side controller to control output power based on the comprehensive information contained within the buffered primary port signal.

Abstract: A controller for use in a power converter includes a control loop clock generator that is coupled to generate a switching frequency signal in response to a sense signal representative of a characteristic of the power converter, a load signal responsive to an output load of the power converter, and a hard switch sense output. A hard switch sense circuit is coupled to generate the hard switch sense output in response to the switching frequency signal and a rectifier conduction signal that is representative of a polarity of an energy transfer element of the power converter. A request transmitter circuit is coupled to generate a request signal in response to the switching frequency signal to control switching of a switching circuit coupled to an input of the energy transfer element of the power converter.

Abstract: A power converter controller includes a control loop clock generator that generates a switching frequency signal in response to a sense signal representative of a characteristic of the power converter, a load signal responsive to an output load, and a limit signal representative of a maximum length of a current half cycle of the switching frequency signal. A comparator generates an enable signal in response to the load signal and a load threshold. A limit control generates the limit signal in response to the enable signal and the switching frequency signal. A rate of change of half cycles of the switching frequency signal is controlled in response to the limit signal. A request transmitter generates a request signal in response to the switching frequency signal to control switching of a switching circuit coupled to the energy transfer element and an input of the power converter.

Abstract: A resonant converter includes a resonant transformer having a leakage inductance and a magnetizing inductance coupled in series to form a resonant transformer input port. The resonant transformer has an output that is coupled to provide an output power to a load. A primary bridge circuit is coupled to provide an input power to the resonant transformer input port. A buffer circuit is coupled in parallel with the resonant transformer input port. A control module is coupled to receive a buffered primary port signal from the buffer circuit to control the primary bridge circuit to control the output power to the load in response to the buffered primary port signal.

Abstract: A resonant converter includes a resonant transformer having a leakage inductance and a magnetizing inductance coupled in series to form a resonant transformer input port. The resonant transformer has an output that is coupled to provide an output power to a load. A primary bridge circuit is coupled to provide an input power to the resonant transformer input port. A buffer circuit is coupled in parallel with the resonant transformer input port. A control module is coupled to receive a buffered primary port signal from the buffer circuit to control the primary bridge circuit to control the output power to the load in response to the buffered primary port signal.

Abstract: A power converter controller includes a control loop clock generator that generates a switching frequency signal in response to a sense signal representative of a characteristic of the power converter, a load signal responsive to an output load, and a limit signal representative of a maximum length of a current half cycle of the switching frequency signal. A comparator generates an enable signal in response to the load signal and a load threshold. A limit control generates the limit signal in response to the enable signal and the switching frequency signal. A rate of change of half cycles of the switching frequency signal is controlled in response to the limit signal. A request transmitter generates a request signal in response to the switching frequency signal to control switching of a switching circuit coupled to the energy transfer element and an input of the power converter.

Abstract: A controller for use in a power converter that is configured to operate in a plurality of modes including a first mode and a second mode includes a frequency monitor module coupled to measure a signal characteristic of a switch drive signal coupled to control switching of a switches block of the power converter. The frequency monitor module includes a memory coupled to store a measured signal characteristic of the switch drive signal measured during the first mode. The frequency monitor module is coupled to generate a clock signal in response to the measured signal characteristic stored in the memory. The switch drive signal is coupled to be generated in response to the clock signal during the second mode.

Abstract: A controller configured for use in a power converter includes a multiplexer that receives a startup clock signal and a request clock signal. The multiplexer selects the startup signal or the request clock signal to generate a clock signal. A startup clock generates the startup clock signal to control a switching frequency of a primary switching circuit during a startup condition. A request clock generates the request clock signal in response to a request signal to control the switching frequency of the primary switching circuit after the startup condition. A control circuit receives the clock signal to generate a drive signal control the switching frequency of the primary switching circuit. The control circuit selects the startup clock signal during the startup condition. The control circuit receives an indication in the request signal of an end of an undervoltage condition and then selects the request clock signal after the startup condition.

Abstract: A controller for use in a power converter includes a control loop clock generator that is coupled to generate a switching frequency signal in response to a sense signal representative of a characteristic of the power converter, a load signal responsive to an output load of the power converter, and a hard switch sense output. A hard switch sense circuit is coupled to generate the hard switch sense output in response to the switching frequency signal and a rectifier conduction signal that is representative of a polarity of an energy transfer element of the power converter. A request transmitter circuit is coupled to generate a request signal in response to the switching frequency signal to control switching of a switching circuit coupled to an input of the energy transfer element of the power converter.

Abstract: A method to control a high side switch of a motor drive includes sinking a current of an ON signal to communicate a turn ON of the high side switch. A first current signal, a second current signal, a third current signal, a fourth current signal and a common mode rejection signal are generated in response to the ON signal. The ON signal in a presence of common mode noise is determined by comparing the first current signal and the second current signal. A first output signal is generated in response to determining the ON signal. A drive signal is generated responsive to the first output signal to control the high side switch in response to the ON signal in presence of common mode noise that is caused by a slewing at a half-bridge node.

Abstract: A controller for use in a power converter of a motor drive includes a control circuit configured to turn ON a high side switch by sinking a current of an ON signal. A high side signal interface circuit is coupled to receive the ON signal to generate a drive signal to control switching of the high side switch in a presence of a common mode signal caused by slewing at a half bridge node. The high side signal interface circuit includes a common mode cancellation circuit coupled to provide a common rejection signal to provide a cancellation or rejection of the common mode signal. A first current hysteresis comparator is coupled to receive a common mode rejection signal, a first current signal, and a fourth current signal, and generate a first output signal in a presence of a common mode voltage.