摘要:
In one embodiment, a power supply controller is configured to switch a power switch of a power supply when a voltage across the switch is at a minimum value.
摘要:
In one embodiment, a power supply controller is configured to switch a power switch of a power supply when a voltage across the switch is at a minimum value.
摘要:
In one embodiment, a charge pump circuit is used to keep a boost capacitor of a power supply system charged while the switch transistors are not switching such as when the power supply system is operating in a burst mode of operation.
摘要:
In one embodiment, a charge pump circuit is used to keep a boost capacitor of a power supply system charged while the switch transistors are not switching such as when the power supply system is operating in a burst mode of operation.
摘要:
A method and circuit for detecting a current and compensating for an offset voltage. The circuit includes two comparators where one of the comparators has two input terminals and the other comparator has three input terminals. An input terminal of each of the two comparators are commonly connected together, the other input terminal of the two-input comparator is coupled for receiving a first reference voltage, and a second input terminal of the three-input comparator is coupled for receiving a second reference voltage. During a first portion of the period of a sense signal the two comparators operate in a sensing mode and during a second portion of the period of the sense signal the comparator having the three input terminals operate in a current nullification mode or an offset voltage compensation mode. An offset compensation signal is generated during the second portion of the sense signal.
摘要:
In one form, a synchronous rectifier controller includes a drive clamp adjust terminal, a drive terminal, a clamp voltage generator circuit coupled to the drive clamp adjust terminal for measuring a signal at the drive clamp adjust terminal and providing a clamp voltage having a value determined by the signal, and a driver for providing a drive signal to the drive terminal at a voltage related to the clamp voltage during an active period of the drive signal. In an alternate form a power converter includes a rectifier transistor having a first current electrode, a control electrode for receiving a drive signal, and a second current electrode, and a synchronous rectifier controller having a first terminal coupled to the control electrode of the rectifier transistor for providing the drive signal alternately in an active state and an inactive state.
摘要:
In one form, a synchronous rectifier controller includes a drive clamp adjust terminal, a drive terminal, a clamp voltage generator circuit coupled to the drive clamp adjust terminal for measuring a signal at the drive clamp adjust terminal and providing a clamp voltage having a value determined by the signal, and a driver for providing a drive signal to the drive terminal at a voltage related to the clamp voltage during an active period of the drive signal. In an alternate form a power converter includes a rectifier transistor having a first current electrode, a control electrode for receiving a drive signal, and a second current electrode, and a synchronous rectifier controller having a first terminal coupled to the control electrode of the rectifier transistor for providing the drive signal alternately in an active state and an inactive state.
摘要:
A method and circuit for detecting a current and compensating for an offset voltage. The circuit includes two comparators where one of the comparators has two input terminals and the other comparator has three input terminals. An input terminal of each of the two comparators are commonly connected together, the other input terminal of the two-input comparator is coupled for receiving a first reference voltage, and a second input terminal of the three-input comparator is coupled for receiving a second reference voltage. During a first portion of the period of a sense signal the two comparators operate in a sensing mode and during a second portion of the period of the sense signal the comparator having the three input terminals operate in a current nullification mode or an offset voltage compensation mode. An offset compensation signal is generated during the second portion of the sense signal.
摘要:
A circuit and method for compensating for parasitic elements of a transistor. A transistor, a controller, and a compensation element are mounted to a printed circuit board. The transistor includes parasitic drain and source inductors. The compensation element may be a discrete inductor that has an inductance value equal to about the sum of the inductance values of the parasitic drain and source inductors. The magnitudes of the compensation voltage and the sum of the voltages across the parasitic drain and source inductances are substantially equal. Thus, the compensation voltage developed across the compensation inductor is used to adjust a reference voltage within the controller. A drain-to-source voltage is applied to one input of a comparator within the controller and the adjusted reference voltage is applied to another input of the comparator. An output signal of the comparator is input to drive circuitry that drives a gate of the transistor.
摘要:
A circuit and method for compensating for parasitic elements of a transistor. A transistor, a controller, and a compensation element are mounted to a printed circuit board. The transistor includes parasitic drain and source inductors. The compensation element may be a discrete inductor that has an inductance value equal to about the sum of the inductance values of the parasitic drain and source inductors. The magnitudes of the compensation voltage and the sum of the voltages across the parasitic drain and source inductances are substantially equal. Thus, the compensation voltage developed across the compensation inductor is used to adjust a reference voltage within the controller. A drain-to-source voltage is applied to one input of a comparator within the controller and the adjusted reference voltage is applied to another input of the comparator. An output signal of the comparator is input to drive circuitry that drives a gate of the transistor.