Patent application number | Description | Published |
20140063875 | START-UP CIRCUIT AND METHOD FOR AC-DC CONVERTERS - An AC-DC power converter includes a rectifying unit for generating a rectified voltage, an output stage for converting the rectified voltage into a DC voltage for a load, a controller for controlling the output stage, and a start-up circuit. The start-up circuit includes a first power section coupled to the rectifying unit and configured to generate a first voltage from the rectified voltage and to output the first voltage to the controller to enable the controller before the output stage starts outputting power. The first power section includes a depletion mode transistor having a first terminal configured to receive the rectified voltage and a second terminal configured to output the first voltage. | 03-06-2014 |
20140126254 | START-UP CIRCUIT AND METHOD WITH SOFT-START SCHEME FOR AC-DC CONVERTERS - An AC-DC power converter includes a rectifying unit, an output stage, a controller and a soft-start circuit. The rectifying unit is configured to rectify an AC voltage to a rectified voltage. The output stage is coupled to the rectifying unit and configured to convert the rectified voltage into a DC voltage for a load. The controller is coupled to the output stage and configured to control the output stage. The soft-start circuit is coupled to the rectifying unit to receive the rectified voltage. The soft-start circuit is configured to detect whether the rectified voltage is at or below a predetermined level, and to enable the controller if the rectified voltage is detected to be at or below the predetermined level. | 05-08-2014 |
20140233283 | STARTUP CIRCUIT AND METHOD FOR AC-DC CONVERTERS - An AC-DC power converter includes a rectifying unit for generating a rectified voltage, an output stage for converting the rectified voltage into a DC voltage for a load, a controller for controlling the output stage, and a start-up circuit. The start-up circuit includes a start-up voltage generator coupled to the rectifying unit and configured to generate a start-up voltage from the rectified voltage and to output the start-up voltage to the controller to provide power for operation of the controller before the output stage starts outputting power. The start-up voltage generator includes a first depletion mode transistor having a first terminal configured to receive the rectified voltage, a second terminal configured to output at least partially the start-up voltage, and a gate terminal which is grounded. | 08-21-2014 |
20150023072 | START-UP CIRCUIT AND METHOD FOR AC-DC CONVERTERS - For starting-up a power converter, an AC rectified voltage is generated upon power-up of the power converter. A depletion mode transistor generates a first voltage from the rectified voltage. The first voltage is inputted to a controller of the power converter to provide power for operation of the controller before an output stage of the power converter starts outputting power. A gate biasing voltage is generated from the first voltage and supplied to a gate terminal of the depletion mode transistor to bias the gate terminal of the depletion mode transistor. | 01-22-2015 |
Patent application number | Description | Published |
20080284391 | FAULT PROTECTION CIRCUIT, METHOD OF OPERATING A FAULT PROTECTION CIRCUIT AND A VOLTAGE REGULATOR EMPLOYING THE SAME - Embodiments of the present disclosure provide a fault protection circuit, a method of operating a fault protection circuit and a voltage regulator. In one embodiment, the fault protection circuit is for use with the voltage regulator and includes an output power section having first and second MOS transistors configured to provide a regulated voltage on an output node of the voltage regulator. The fault protection circuit also includes a gate pull-down section connected to the first and second MOS transistors and configured to provide a gate pull-down MOS transistor to limit a current through the first and second MOS transistors during a current overload fault condition on the output node. | 11-20-2008 |
20090115379 | Soft-Start Circuit for Power Regulators - One embodiment of the present invention includes a system for providing a soft-start for a power regulator comprising a differential transistor pair that receives an input current and conducts a first current through a first transistor and a second current through a second transistor. One of the first and second current changes in response to a change in the other to maintain a sum of the first and second current being substantially equal to the input current. The system also comprises a comparator that provides an output signal based on a comparison of a first input voltage and a second input voltage associated with the first current and the second current, respectively. The system further comprises a current source activated by the output signal to charge a capacitor that increases a soft-start reference voltage associated with control of the power regulator and which controls the change in the other of the first and second current. | 05-07-2009 |
20090160410 | REAL TIME CLOCK (RTC) VOLTAGE REGULATOR AND METHOD OF REGULATING AN RTC VOLTAGE - A real time clock (RTC) voltage regulator, a method of regulating an RTC voltage and a power management integrated circuit (PMIC). In one embodiment, an RTC voltage regulator includes a current source configured to provide a first current and a voltage regulator having a common gate amplifier and a power device. The first current is employed to establish a reference voltage for the common gate amplifier and the common gate amplifier is configured to control the power device. The power device is configured to provide an RTC voltage for the common gate amplifier. | 06-25-2009 |
20090167266 | FAULT PROTECTION CIRCUIT, METHOD OF OPERATING A FAULT PROTECTION CIRCUIT AND A VOLTAGE REGULATOR EMPLOYING THE SAME - Embodiments of the present disclosure provide a fault protection circuit, a method of operating a fault protection circuit and a voltage regulator. In one embodiment, the fault protection circuit is for use with the voltage regulator and includes an output power section having first and second MOS transistors configured to provide a regulated voltage on an output node of the voltage regulator. The fault protection circuit also includes a gate pull-down section connected to the first and second MOS transistors and configured to provide a gate pull-down MOS transistor to limit a current through the first and second MOS transistors during a current overload fault condition on the output node. | 07-02-2009 |
20090289608 | SOFT-START CIRCUIT FOR POWER REGULATORS - One embodiment of the present invention includes a system for providing a soft-start for a power regulator comprising a differential transistor pair that receives an input current and conducts a first current through a first transistor and a second current through a second transistor. One of the first and second current changes in response to a change in the other to maintain a sum of the first and second current being substantially equal to the input current. The system also comprises a comparator that provides an output signal based on a comparison of a first input voltage and a second input voltage associated with the first current and the second current, respectively. The system further comprises a current source activated by the output signal to charge a capacitor that increases a soft-start reference voltage associated with control of the power regulator and which controls the change in the other of the first and second current. | 11-26-2009 |
20100117682 | Level-Shifter Circuit - One embodiment of the invention includes a level-shifter circuit. The circuit comprises a control stage that steers a current from one of a first control node and a second control node to the other of the first control node and the second control node based on an input signal to set a first initial voltage at the first control node and a second initial voltage at the second control node, the input signal having logic-high and logic-low voltage magnitudes that occupy a low voltage domain. The circuit also includes a logic driver that is coupled to the second control node and is referenced in a high voltage domain. The logic driver can be configured to provide an output signal having logic-high and logic-low voltage magnitudes that occupy the high voltage domain based on the second initial voltage. | 05-13-2010 |
20100164457 | Voltage Regulator Circuit - One embodiment of the invention includes a regulator circuit that regulates a substantially constant magnitude of an output voltage at an output node. The circuit includes a master stage configured to set a first threshold voltage and a second threshold voltage. The first threshold voltage can have a magnitude that is greater than the second threshold voltage. The circuit also includes a charging follower stage configured to conduct a first current from a first power rail to the output node. The first current can increase in response to a transient decrease of the output voltage relative to the first threshold voltage. The circuit further includes a discharging follower stage configured to conduct a second current from the output node to a second power rail. The second current can increase in response to a transient increase of the output voltage relative to the second threshold voltage. | 07-01-2010 |
20130038309 | VOLTAGE REGULATOR CIRCUIT - One embodiment of the invention includes a regulator circuit that regulates a substantially constant magnitude of an output voltage at an output node. The circuit includes a master stage configured to set a first threshold voltage and a second threshold voltage. The first threshold voltage can have a magnitude that is greater than the second threshold voltage. The circuit also includes a charging follower stage configured to conduct a first current from a first power rail to the output node. The first current can increase in response to a transient decrease of the output voltage relative to the first threshold voltage. The circuit further includes a discharging follower stage configured to conduct a second current from the output node to a second power rail. The second current can increase in response to a transient increase of the output voltage relative to the second threshold voltage. | 02-14-2013 |