Patent application number | Description | Published |
20090212870 | CASCODE-CASCADE POWER AMPLIFIER ASSEMBLY - A cascode-cascade power amplifier assembly is provided. Which includes a first common-source amplifier, a second common-source amplifier, a phase shift matching network coupled to the first common-source amplifier and the second common-source amplifier for providing a 90-degree phase shift and allowing less than 50% of the output power of the first common-source amplifier to be transmitted to the second common-source amplifier, a common-gate amplifier which forms a series circuit arrangement with the first-common source amplifier and a parallel circuit arrangement with the second common-source amplifier, and an equivalent quarter-wave or three-quarter wave circuit which forms a series circuit arrangement with the common-gate amplifier and a parallel circuit arrangement with the second common-source amplifier. According to the present invention, the first common-source amplifier and the common-gate amplifier form a cascode main amplifier, while the first common-source amplifier and the second common-source amplifier form a cascade auxiliary amplifier. | 08-27-2009 |
20090309561 | DUAL MODE TRANSIENT RECOVERY CONTROL METHOD OF DC-DC CONVERTERS - A dual mode transient recovery control method and system is proposed, which is designed for use with a direct-current (DC) power output unit, such as a DC-DC converter, for fast transient recovery of DC output power by switching the DC-DC converter to operate between a hysteretic mode and a PWM (Pulse Width Modulation) mode. The proposed control method and system is characterized by the use of a dual-threshold scheme to compare the output voltage. This feature may discharge the transient output voltage, raised by the over-shoot, to the steady state by switching to the discharging mode, and similarly charge the transient output voltage, dropped by the under-shoot, to the steady state by switching to the charging mode. This mechanism may allow DC-DC converters with higher slew rate to make transient ripples of output voltage to return to steady state more quickly, and additionally allow a better level of noise immunity. | 12-17-2009 |
20090322294 | CONTROL DEVICE FOR TRANSIENT RECOVERY OF DC-DC CONVERTERS - A control device for fast transient recovery of the output voltage of DC-DC converters. The control device is characterized by using a dual-threshold method to compare the actually received loading voltage values on the loading terminals of DC-DC converters, i.e., a total of four threshold levels including a negative-ripple falling-edge threshold and a negative-ripple rising-edge threshold on the negative polarity, and a positive-ripple rising-edge threshold and a positive-ripple falling-edge threshold on the positive polarity. During the transient, the load current charging/discharging control device disclosed in the invention may be switched between charging and discharging mode based on the relation between two-pairs threshold values and output voltage amplitude of DC-DC converters. This mechanism may allow DC-DC converters with higher slew rate to make transient ripples on output voltage to return to steady state more quickly. | 12-31-2009 |
20100171727 | Output Buffer Circuit with Enhanced Slew Rate - An output buffer circuit with enhanced slew rate is disclosed. A first and a second slew-rate enhancing transistor are configured to enhance the slew rate of the source transistor and the sink transistor of an output stage. A first control circuit and a second control circuit turn off the first and the second slew-rate enhancing transistors during the static state, and turn on the first and the second slew-rate enhancing transistors during the transition. | 07-08-2010 |