Texas Instruments Corporation

Michael Douglas Seeman

Sandeep Raj Bahl

David I Anderson

Bin Gu

In described examples, a first transistor has: a drain coupled to a source of a depletion-mode transistor; a source coupled to a first voltage node; and a gate coupled to a control node. A second transistor has: a drain coupled to a gate of the depletion-mode transistor; a source coupled to the first voltage node; and a gate coupled through at least one first logic device to an input node. A third transistor has: a drain coupled to the gate of the depletion-mode transistor; a source coupled to a second voltage node; and a gate coupled through at least one second logic device to the input node.

Method and circuitry for controlling a depletion-mode transistor

A hysteretic controller coupled to a first inductor and a second inductor, the first inductor is coupled to a secondary side of a transformer, the second inductor is coupled to the secondary side of the transformer and the hysteretic controller includes: a hysteretic comparator including a first input, a second input, and an output, the first input configured to receive a sensed current from the first inductor and the second inductor, the second input configured to receive a differential voltage representing a potential difference between an output voltage of a power converter and a reference voltage; a pulse sequencer coupled to the output of the hysteretic comparator; and a dead-time generation circuit configured to provide a first on-time signal to a first switch coupled to a primary side of the transformer and a second on-time signal to a second switch coupled to the secondary side of the transformer, the first and second on-time signals based on a pulse signal received from the pulse sequencer.

Hysteretic control for transformer based power converters

Hysteretic control for power converters. In an example arrangement, an apparatus includes a converter for converting an input voltage to an output voltage including a transformer; at least one primary side driver switch coupled to supply current from an input voltage terminal to the primary side of the transformer; at least one inductor coupled between the secondary side of the transformer and the output voltage terminal; at least one secondary side switch coupled between the inductor and a ground potential; and a hysteretic controller coupled to supply a first on-time signal to the at least one primary side switch and a second on-time signal to the at least one secondary side switch, the hysteretic controller configured for sensing the output voltage and having at least one current input coupled for sensing current flowing in the inductor and generating primary side driver switch on-time pulses to control the output voltage.

A high-voltage transistor (HVT) structure adapts a low-voltage transistor (LUT) to high-voltage environments. The HVT structure includes a drain node, a source node, a control gate, and a field electrode. The drain node and the source node define a conductive channel, in which mobilized charges are regulated by the control gate. While being isolated from the control gate, the field electrode is configured to spread the mobilized charges in response to a field voltage. The field electrode is structured and routed to prevent charge sharing with any one of the drain node, source node, or control gate. Advantageously, the isolated field electrode minimizes the capacitance of the control gate as well as the drain and source nodes, such that the HVT can switch with less power loss and a more robust performance in a high-voltage environment.

High voltage device with multi-electrode control

Disclosed examples include switching power converters, control methods and ripple filter circuits in which first and second switches are connected in series across first and second DC bus nodes, with an inductor connected to a switching node joining the first and second switches and a storage capacitor between the inductor and the second DC bus node. A control circuit operates the switches to alternately transfer ripple energy from a DC bus capacitor of the DC bus circuit through the inductor to the storage capacitor, and then to transfer ripple energy from the storage capacitor through the inductor to the DC bus capacitor to regulate the ripple voltage of the DC bus circuit, and the control circuit provides hysteretic control of the absolute value of the inductor current between a first value and a higher second value during transfer of ripple energy between the DC bus capacitor and the storage capacitor.

Switching converter with improved power density

A high-voltage transistor (HVT) structure adapts a low-voltage transistor (LVT) to high-voltage environments. The HVT structure includes a drain node, a source node, a control gate, and a field electrode. The drain node and the source node define a conductive channel, in which mobilized charges are regulated by the control gate. While being isolated from the control gate, the field electrode is configured to spread the mobilized charges in response to a field voltage. The field electrode is structured and routed to prevent charge sharing with any one of the drain node, source node, or control gate. Advantageously, the isolated field electrode minimizes the capacitance of the control gate as well as the drain and source nodes, such that the HVT can switch with less power loss and a more robust performance in a high-voltage environment.

A circuit for sensing current in a capacitive network. A first capacitor carries a first current. A second capacitor is connected to the first capacitor thereby forming a current divider. The second capacitor carries a second current which is proportional to the first current. A transimpedance amplifier is connected to the second capacitor and has a voltage output that is proportional to the second current. Using a current feedback amplifier as the transimpedance amplifier significantly improves bandwidth and stability.

Growing community of inventors

San Jose, CA, United States of America

Michael Douglas Seeman