Texas Instruments Corporation

Bing Lu

Bharath Balaji Kannan

Pei-Hsin Liu

Isaac D Cohen

Robert Allan Neidorff

Ulrich B Goerke

A controller integrated circuit for controlling a voltage converter. The controller IC includes a transistor control driver terminal and a power terminal. A driver has a driver input, a driver output, and a driver supply voltage input. The driver output is coupled to the transistor control driver terminal, and the driver supply voltage input is coupled to the power terminal. Logic has a first logic output and a second logic output. A first transistor has a first control input, a first current terminal, and a second current terminal. The first logic output is coupled to the first control input, and the first current terminal is coupled to the power terminal. A second transistor has a second control input, a third current terminal, and a fourth current terminal. The second logic output is coupled to the second control input, and the third current terminal couples to the transistor control driver terminal.

Controller for a voltage converter

Methods, apparatus, systems, and articles of manufacture are disclosed for adaptive synchronous rectifier control. An example apparatus includes an adaptive off-time control circuit to determine a first voltage and a second voltage when a drain voltage of a switch satisfies a voltage threshold, the first voltage based on a first off-time of the switch, the second voltage based on the first off-time and a first scaling factor, determine a third voltage based on a second scaling factor and a second off-time of the switch, the second off-time after the first off-time, and determine a third off-time of the switch based on at least one of the second voltage or the third voltage. The example apparatus further includes a driver to turn off the switch for at least the third off-time after the second off-time.

Methods and apparatus for adaptive synchronous rectifier control

A synchronous rectifier control circuit includes a drain voltage input, a first gate voltage output, a second gate voltage output, a gate voltage generation circuit, and a trigger control circuit. The gate voltage generation circuit includes a first input coupled to the drain voltage input, and an output coupled to the first gate voltage output. The trigger control circuit includes a first input coupled to the first gate voltage output, a second input coupled to the second gate voltage output, and an output coupled to a second input of the gate voltage generation circuit.

Synchronous rectifier control circuit

A synchronous rectifier control circuit includes a drain voltage input, a gate voltage output, a gate voltage generation circuit, a burst detection circuit, an on-time monitor circuit, and a burst mode reset circuit. The gate voltage generation circuit includes a first input coupled to the drain voltage input, and an output coupled to the gate voltage output. The burst detection circuit includes a first input coupled to the drain voltage input, and an output coupled to a second input of the gate voltage generation circuit. The on-time monitor circuit includes an input coupled to the output of the gate voltage generation circuit. The burst mode reset circuit includes a first input coupled to the drain voltage input, a second input coupled to an output of the on-time monitor circuit, and an output coupled to a second input of the burst detection circuit.

Synchronous rectifier control

These teachings apply with respect to a direct current (DC)-output converter and provide for adjusting a number of switching pulses per burst cycle as a function, at least in part, of converter output loading. This adjustment can be made by controlling burst frequency with respect to at least one predetermined threshold frequency. The predetermined threshold frequency can comprise a non-audible frequency such that the number of switching pulses is adjusted to prevent the burst frequency from itself constituting an audible signal. The adjustment of the number of switching pulses per burst cycle may only occur when the output loading is less than a predetermined level of loading. These teachings may also provide for clamping the pulse frequency for the pulses in each burst package to a particular value when dynamically controlling the number of pulses in each burst package. The aforementioned particular value may constitute, for example, a highest available switching frequency.

Adaptive burst generation for use with a DC-output converter

A synchronous rectifier controller integrated circuit. The synchronous rectifier controller integrated circuit comprises a continuous current mode (CCM) detection circuit configured to detect CCM operation based on sensing a voltage at a pre-defined point in a rectification cycle; a multiplexer having a first reference voltage signal input, a second reference voltage signal input, an output, and a selector input coupled to the CCM detection circuit; and a gate voltage driver circuit coupled to the output of the multiplexer.

Synchronous rectifier controller integrated circuits

An electronic device includes a power stage, a switch and a controller. Power is transferred from an input through the power stage to an output. The switch turns on and off a current provided to the power stage for transferring the power. The controller turns on and off the switch. During a low-load mode, the controller causes the switch to operate with a constant on-time control.

Constant on-time control for power converter

On the secondary side of a flyback switching power converter, a compensation diode and a voltage divider with an averaging circuit generate an output current-compensated reference voltage that is proportional to converter output current. The current-compensated reference voltage is added to a regulation feedback controller reference voltage, which in turn adjusts the negative feedback signal to the PWM regulation controller on the primary side in proportion to the converter output current draw. The net effect is to increase the converter output voltage set-point in proportion to the converter output current draw as compensation for a voltage drop in a cable connecting the converter to a powered device. More precisely-regulated voltage levels may be delivered to an input of the powered device as a result.

Voltage converter compensation apparatus and methods

An apparatus for generating an output voltage from an input voltage is provided. The apparatus comprises a switch that receives the input voltage, an inductor that is coupled to the switch, a capacitor coupled to the inductor with the output voltage being output from a node between the inductor and the capacitor, a measuring circuit that receives and measures the input voltage, and a controller that is coupled to the switch and to the measuring circuit. Additionally, the controller receives the measured input voltage and calculates an on-time for the switch based on the measured input voltage and actuates the switch for the on-time.

Controlled on-time buck PFC

In a first aspect, an LLC resonant converter is provided for driving a plurality of output circuits from a DC input signal. The LLC resonant converter includes: (a) an inverter circuit for converting the DC input signal to a square-wave signal; (b) an inductor network coupled to the inverter circuit; and (c) a plurality of transformers, each transformer including a primary winding and a secondary winding. The primary windings of the transformers are coupled in series, and the series-coupled primary windings are coupled in parallel with the inductor network. The secondary winding of each transformer is coupled to and provides a current to a corresponding one of the output circuits. The secondary winding currents are substantially equal, and power is processed by a single transformer between the DC input signal and each output circuit. Numerous other aspects are also provided.

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Bedford, NH, United States of America

Bing Lu