Monolithic Power Systems, Inc.

Adaptive Digital Power, Inc.

Fairchild Semiconductor Corporation

Andrew Wu

Donald Wile

Christopher Thomas Falvey

Systems and methods are disclosed to detect current for an output load with an inductor. The system includes a high side power transistor a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors.

Adaptive non-positive inductor current detector (ANPICD)

A current detector for an output load includes a high side power transistor; a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors to provide cycle by cycle control of the conduction of the high and low side power transistors, wherein if the controller detects zero or negative current in the output inductor, using a dead time between when the low side power transistor turns off and before the high side power transistor turns on, the low side power transistor is held off during the entirety of the next switching cycle.

Non-positive inductor current detector for step down switching regulators

Systems and methods are disclosed to detect current for an output load with an inductor. The system includes a high side power transistor a low side power transistor coupled to the high side power transistor; and a controller coupled to the high and low side power transistors to provide cycle by cycle conduction of the low side power transistor, said controller adaptively turning off the low side power transistor when the high and low side power transistors are off and an inductor current is non-positive. Adaptation of the turn off of the low side transistor is based on the time position of the detection of the non-positive inductor current and serves to improve the power efficiency of the system.

A regulator with a high side pass device and a low side pass device coupled in series to the high side pass device is disclosed. The apparatus further includes a control module coupled to the high side pass device and the low side pass device. The control module is coupled to the high side pass device and the low side pass device to control the high side pass device and the low side pass device. The control module is operable to lock out the high side pass device under certain conditions.

Short circuit current ratcheting in switch mode DC/DC voltage regulators

In one embodiment, a method is provided for a power converter system. The method includes: providing a primary current limit for the power converter system, wherein the power converter system has one or more transistors which can be switched on at a primary frequency to cause current to flow through an inductor of the power converter system; and using the primary current limit for over-current protection in the power converter system, wherein over-current protection does not employ any secondary frequency for switching of the one or more transistors and does not employ any secondary current limit.

Over-current protection for a power converter

A switch-mode DC/DC converter and a linear low drop out (LDO) DC/DC regulator are connected in parallel to drive a single load. Both regulators share a common voltage reference, feedback network, input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator disabled, also maximizing the efficiency. Each regulator senses load current to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators to minimize the voltage transients.

DC/DC voltage regulator with automatic current sensing selectability for linear and switch mode operation utilizing a single voltage reference

In an embodiment, an apparatus is provided. The apparatus includes a high side pass device. The apparatus also includes a low side pass device coupled in series to the high side pass device. The apparatus further includes a control module coupled to the high side pass device and the low side pass device. The control module is coupled to the high side pass device and the low side pass device to control the high side pass device and the low side pass device. Additionally, the apparatus includes a first resistor coupled in series with the high side pass device and the low side pass device. Furthermore, the apparatus includes a first comparator coupled in parallel with the first resistor. The first comparator has a threshold voltage input differential corresponding to a first current limit, and an output of the first comparator is coupled to the control module. Moreover, the apparatus includes a second comparator coupled to sense current of the high side pass device as a voltage. The second comparator has a threshold voltage input differential corresponding to a second current limit. An output of the second comparator is coupled to the control module. The second current limit is higher than the first current limit. Also, the control module is operable to lock out the high side pass device responsive to the output of the first comparator until a reset signal is received and is operable to lock out the high side pass device responsive to the output of the second comparator until a low current signal is received.

A switch-mode DC/DC converter () and linear low drop out (LIDO) DC/DC regulator () are connected in parallel to drive a single load Both regulators share a common voltage reference, feedback network (), input supply and output such that the regulated voltage is identical during each mode of operation. During heavy loads the switch-mode regulator () is in operation and the linear regulator is disabled for the highest efficiency possible. Conversely at light loads the linear regulator is in operation with the switch-mode regulator () disabled, also maximizing the efficiency. Each regulator senses load current () to automatically transition between the appropriate voltage regulators at fixed load current levels. The presented invention also includes a make before break transition scheme of the voltage regulators () to minimize the voltage transients.

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Campbell, CA, United States of America

Andrew Wu