| Patent application number | Description | Published |
|---|
| 20100201335 | OFF TIME CONTROL METHOD FOR SWITCHING REGULATOR - The present invention provides an off time control method and switching regulator using it. The current flowing through a switch is compared with a current threshold, and the switch is turned off if the current flowing through the switch is larger than the current threshold. The off time of the switch is determined by the load. The current threshold is variable at light load to prevent generating the audible noise and improve the whole efficiency. | 08-12-2010 |
| 20100214807 | INTERNAL HIGH-VOLTAGE CURRENT SOURCE IN AN AC/DC POWER CONVERTER - AC/DC power converters having an under voltage lockout circuit with first and second thresholds and associated methods of operation are disclosed herein. In one embodiment, the first threshold is greater than the second threshold. The under voltage lockout circuit is configured to enable a current source to charge the capacitor when the voltage across the capacitor is less than the second threshold. The under voltage lockout circuit is configured to shut off the current source and to enable a pulse width modulator circuit to switch a transistor when the voltage is greater than the first threshold. | 08-26-2010 |
| 20100302813 | DUAL-MODE CONSTANT LOAD CONTROL CIRCUITS AND ASSOCIATED METHODS - Dual-mode AC/DC power converters and associated methods of operation are disclosed herein. In one embodiment, the AC/DC converter includes a primary winding, a switching transistor coupled to the primary winding, the switching transistor configured to carry a drain-source current, and a feedback voltage port configured to carry a feedback voltage. The feedback voltage port is coupled to the switching transistor to switch off the switching transistor when the drain-source current reaches a peak current limit. The peak current limit increases with increasing feedback voltage if and only if the feedback voltage satisfies an ordered relationship with a threshold. | 12-02-2010 |
| 20100302814 | CONTROLLER FOR SWITCHING POWER SUPPLY - A switching power supply has an inductor that includes a coil. A chopper circuit chops the primary current drawn through the coil, for the inductor to output an induced current. A multifunction junction of the power supply has a multifunction voltage that is a function of a primary voltage that drives the coil. A first circuit suspends the chopping in response to a first sensed voltage crossing a first threshold, the first sensed voltage being a function of the multifunction voltage. A second circuit suspends the chopping in response to a second sensed voltage crossing a second threshold, the second threshold being a function of the multifunction voltage. | 12-02-2010 |
| 20100302815 | SWITCHING MODE POWER SUPPLY WITH A MULTI-MODE CONTROLLER - A switching mode power supply with a multi-mode controller is provided. The switching mode power supply may include a transformer having a primary winding and a secondary winding to supply power to a load. A feedback circuit may be included to generate a feedback signal that varies in relation to the load on the secondary winding. The multi-mode controller may include a switching circuit, a frequency control circuit and a current limiting circuit. The switching circuit may be coupled to the primary winding to control current flow through the primary winding. The frequency control circuit may control a switching frequency of the switching circuit based on the feedback signal. The current limiting circuit may limit current flow through the primary winding by causing the switching circuit to suspend current flow through the primary winding when the current reaches a peak current limit that is set based on the feedback signal. | 12-02-2010 |
| 20110051470 | SWITCHING MODE POWER SUPPLIES AND ASSOCIATED METHODS OF CONTROL - Switching mode power supplies and associated methods of control are disclosed herein. In one embodiment, a method for controlling a switching mode power supply includes determining whether the switching mode power supply is in a burst mode. If the switching mode power supply is in the burst mode, the method includes recording a switching time with and without switching pulses to obtain a current value of an equivalent frequency and generating a peak current limit that decreases as a load becomes lighter based on the equivalent frequency, thereby maintaining the equivalent frequency at the current value above an audible range. If the switching mode power supply is not in the burst mode, the method includes continuing to monitor whether the switching mode power supply is in the burst mode. | 03-03-2011 |
| 20110110123 | SWITCHING MODE POWER SUPPLY SPECTRUM SHAPING AND THE METHOD THEREOF - Embodiments of circuits and methods for a switching mode power supply are described in detail herein. In one embodiment, a switching mode power supply includes a transformer having a primary winding and a secondary winding to supply power to a load, a feedback circuit that generates a feedback signal that varies in relation to the load on the secondary winding, a switching circuit coupled to the primary winding to control current flow through the primary winding, and a control circuit coupled to the switching circuit to control the on/off status of switching circuit in response to the feedback signal and the current flow through the primary winding. The control circuit comprises a spectrum shaping circuit configured to generate a spectrum shaping signal in response to the feedback signal. The spectrum shaping signal can then be used to regulate the switching frequency and the spectrum shaping range. | 05-12-2011 |
| 20110228570 | SWITCHING MODE POWER SUPPLIES WITH PRIMARY SIDE CONTROL AND ASSOCIATED METHODS OF CONTROL - Switching mode power supplies with primary side control and associated methods of control are disclosed. In one embodiment, a signal with input voltage information and a signal with both input voltage information and output voltage information are provided to a subtracter to generate a feedback signal that is indicative of the output voltage. The feedback signal is then used to control the switching mode power supply. | 09-22-2011 |
