Texas Instruments Corporation

James L Krug

David W Evans

J Patrick Kawamura

Jun Chen

Valerian Mayega

Kevin Scoones

Pradeep Katikaneni

Systems and methods of driving multiple outputs are provided in which a single inductor may be used to drive multiple output such as independent strings of LEDs or white LEDs (WLEDs). In an example embodiment, a boost DC to DC converter may be used with a single inductor to drive multiple outputs. In an example embodiment, the error voltage of each of the multiple outputs is sampled during each cycle of the DC to DC converter and the largest error voltage is determined for that cycle. Power from the DC to DC converter is then supplied to that output during that cycle.

Systems and methods of driving multiple outputs

A single-inductor dual-output buck converter facilitates power conversion by converting a single DC power source/supply into two separate DC outputs, each of which can be configured to provide a selected/desired voltage. The converter includes a single inductor and three power switches, which control operation of the converter. The converter has four basic stages of operation in which power is initially supplied to a first output that also stores charge. Subsequently, the stored charge of the first output is employed to provide power to a second output.

Single inductor dual output buck converter

A switching mode converter, having a switching transistor and an inductor, has a discontinuity detector coupled to the inductor which detects when the converter enters the discontinuous mode. The discontinuity detector determines the portion of the cycle of the switching transistor in which the converter is in the discontinuous mode. A feedback controller is coupled to the output of the converter and to the discontinuity detector which alters a feedback control signal of the converter.

DC/DC converter having improved regulation

A single-inductor dual-output buck converter and control method that facilitates power conversion by converting a single DC power source/supply into two separate DC outputs, each of which can be configured to provide a selected/desired voltage by selection of respective duty cycles. The topology of the inverter includes a pair of diodes or switches that can selectively re-circulate inductor current. The converter is generally operated at a fixed frequency with four stages of operation. A first and third stage of operation provide power to a first and second output, respectively. A second and fourth stage of operation re-circulate inductor current and can partially recharge a battery type power source. The power output for each stage (voltage and current) can be selectively obtained by computing and employing appropriate time periods for the stages of operation that correspond to appropriate duty cycles.

Single inductor dual output buck converter with frequency and time varying offset control

A DC/DC switching regulator has a semiconductor switch coupled to an inductor, a first capacitor and a rectifier. A circuit to improve the switching efficiency of the semiconductor switch has a transmission gate coupled between the gate of the semiconductor switch and a second capacitor. The transmission gate is turned ON only when the gate of the semiconductor switch is about to make a positive or negative transition and isolated from the first and second voltage sources. A portion of the charge stored in the parasitic capacitance of the gate of the semiconductor switch can be stored in the second capacitor and reused to partially drive the semiconductor switch from the second to the first ON/OFF state. A further embodiment employs this technique with a synchronous rectifier in the regulator circuit.

DC/DC switching regulator having reduced switching loss

Startup operation of a DC/DC switching regulator is controlled by providing a first signal (MAXDC) whose waveform has a duty cycle that varies over time, providing a second signal ( ) indicative of a load condition of the regulator, and combining the first and second signals to produce a third signal ( ). The third signal is used to control a power switch ( ) of the regulator.

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Carrollton, TX, United States of America

James L Krug