Texas Instruments Corporation

Bhaskar Ramachandran

Rengang Chen

Dattatreya Baragur Suryanarayana

Evan Reutzel

Aalok Dyuti Saha

Preetam Charan Anand Tadeparthy

Preetam Tadeparthy

Kushal D Murthy

Scott Edward Ragona

Vishnuvardhan Reddy Jaladanki

Bo Wang

Vishal I Gupta

Somshubhra Paul

Jae Won Choi

Srinivasan Venkataraman

Sujan Kundpur Manohar

An apparatus includes a first variable resistor having a first resistor control terminal and a second variable resistor having a second resistor control terminal. The apparatus also includes a temperature sensing circuit having a temperature sensing output, the temperature sensing circuit configured to provide a device temperature indication at the temperature sensing output. Additionally, the apparatus includes a controller having a controller input, a controller output, the controller input coupled to the temperature sensing output, the controller output coupled to the first resistor control terminal and to the second resistor control terminal, the controller configured to produce a control signal at the controller output responsive to the device temperature indication.

Rdson-based current sensing system

In an example, a circuit includes an emulated current generator configured to provide an emulated current signal responsive to a charge current and a discharge current. The emulated current signal can be representative of an emulated current through an output inductor. A comparator is configured to provide a comparator signal responsive to the emulated current signal and sensed current signal representative of a measure of current through the output inductor. An inductor code counter is configured to adjust an inductor code count value responsive to the comparator signal. A slope of the emulated current signal can be adjusted responsive to the inductor code count value.

Inductance detection for power converters

A DC-DC converter includes a current sense circuit. The current sense circuit includes a sense current output, an inductor current measurement circuit, an inductor current emulation circuit, a first switch, and a second switch. The inductor current measurement circuit has an output. The inductor current emulation circuit has an output. The first switch is coupled between the output of the inductor current measurement circuit and the sense current output. The second switch is coupled between the output of the inductor current emulation circuit and the sense current output.

DC-DC converter with hybrid current sensing

A device includes a current mirror, a switch, first and second current paths, first and second buffers, a variable resistor, a temperature-sensing circuit, and a controller. The first current path is coupled between the current mirror's input and the switch. The switch switches between ground and a transistor based on a control signal. The second current path is coupled between a first current mirror output and ground. The first buffer is coupled to a second current mirror output. The second buffer is coupled to the variable resistor, which is coupled to the first buffer. The temperature-sensing circuit provides a device temperature to the controller, which is coupled to a first buffer output and determines a first adjustment to the first and second current paths and a second adjustment to the variable resistor based on the device temperature.

A device includes a first transistor coupled to an input voltage source and to an output voltage node and an amplifier comprising a first input, a second input, and an output. The device also includes a second transistor coupled to the input voltage source and the first input of the amplifier and a third transistor coupled to the second transistor and a ground node. The third transistor includes a control terminal coupled to the output of the amplifier. The device also includes a first voltage-controlled voltage source coupled to a control terminal of the first transistor and a control terminal of the second transistor and a second voltage-controlled voltage source coupled to the first transistor and the second input of the amplifier.

Load current sensing at low output voltage

A servo-amplifier includes a first bipolar transistor, a second bipolar transistor, a cascode transistor, and a bias transistor. The second bipolar transistor includes an emitter terminal that is connected to an emitter terminal of the first bipolar transistor to form a differential amplifier. The cascode transistor includes a source terminal that is connected to a collector terminal of the first bipolar transistor. The bias transistor is coupled to the first bipolar transistor, the second bipolar transistor and the cascode transistor. The bias transistor is configured to generate a bias voltage to drive a gate terminal of the cascode transistor based on a voltage at a base terminal of the first bipolar transistor and a voltage at a base terminal of the second bipolar transistor. As a result, neither of the bipolar transistors enters a saturation region during transient or steady state operation.

Servo-amplifier with closed-loop biasing

A system includes a first transistor having a first control input and first and second current terminals. The first current terminal couples to an input voltage node. A second transistor has a second control input and third and fourth current terminals. The third current terminal couples to the second current terminal at a first node. The fourth current terminal couples to an output voltage node. A drive circuit is configured to charge a capacitor maintain the first transistor in an off state responsive to a negative voltage on the input voltage node, and, responsive to a negative voltage on the input voltage node, to cause the charge from the capacitor to be used to turn off the first transistor. The system provides a voltage to a load coupled to the output voltage node.

Control of a power transistor with a drive circuit

In described examples, a circuit includes a first driver. The first driver is coupled to a first node, and the first node is coupled to an output pin. A second driver is coupled to a second node, and the second node is coupled to a first voltage terminal. A comparator is coupled to the first node and the second node. A sustaining driver is coupled to the comparator and provides a threshold current to each of the first node and the second node when a short is detected at the output pin.

Short detect scheme for an output pin

An apparatus includes a power transistor to conduct a load current from a supply voltage node to an output node and a current sense circuit coupled to the power transistor. The current sense circuit generates a current sense current proportional to the load current. A temperature sense circuit is included to generate a temperature sense voltage proportional to the temperature of the power FET. A thermal limit circuit is coupled to the temperature sense circuit. A current limit circuit is coupled to the current sense circuit and to the thermal limit circuit. The current limit circuit generates a control signal on a current limit circuit output node. The control signal is responsive to the current sense current and to a first current from the thermal limit circuit. The current limit circuit output node is coupled to a control input of the power transistor.

Temperature dependent current limit control for fast-charging and safe operating area (SOA) protection

One example includes a power supply system. The system includes a power stage comprising at least one power switch that is periodically activated during an on-time of a duty-cycle based on a switching signal to generate an output voltage at an output. The system also includes a switching controller configured to generate the switching signal based on an amplitude of a capacitor voltage at a control node associated with a capacitor that defines the on-time of the duty-cycle as a function of the capacitor being periodically charged. The switching controller includes a pre-bias stage configured to apply a pre-bias charge to the capacitor via an offset voltage prior to a start of the on-time to pre-charge parasitic capacitance associated with the power supply system prior to the start of the on-time.

Precharging a capacitor with an offset to mitigate control delays in a buck converter

A single sleep mode controller which ensures that there is at least a corresponding minimum voltage level across capacitors when the corresponding regulators are turned off. In an embodiment, the sleep mode controller uses a single comparator which compares the voltages across capacitors in a time division multiplexed (TDM) manner, and initiates the charging operation for the capacitor if the voltage level falls below a corresponding minimum voltage level. The sleep mode controller continues the charging operation until the voltage level exceeds a corresponding upper threshold value. Due to the use of the single controller, power and/or space savings may be attained.

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Coimbatore, India

Bhaskar Ramachandran