Texas Instruments Corporation

Sanmukh Makan Patel

Ross Eliot Teggatz

David John Baldwin

Zbigniew Jan Lata

Timothy John Legat

William E Grose

Suribhotla Rajasekhar

Rex M Teggatz

Valerian Mayega

Juan F Alvarez

Dave Baldwin

A reverse battery protection circuits that provides an integrated reverse battery condition solution for protection of external NMOS switches during the reverse battery condition is disclosed herein. This reverse battery protection circuit minimizes power consumption during a reverse battery event wherein there is no need for mechanical adjustments such as heat sinking and clamping to extract the heat away from the silicon and not destroy the device. Specifically, the reverse battery protection circuit includes a push-pull gate drive circuit coupled between the first and second power supply rail. A protection subcircuit portion connects between a first output node and the second power supply rail to turn the external FET 'on' during the reverse battery condition. In particular, the protection subcircuit portion connects to the external FET device and includes a p-channel device connected between a second output node that biases the external FET device and a first diode. A resistor connects between a first output node of the reverse battery protection circuit to provide a voltage drop between the drain terminal and the gate of the p-channel device. A second diode connects between the gate and the source of the p-channel device. In addition, a clamping circuit connects between the second output node and the third output node to provide clamping in the instance where the voltage at the second output node momentarily rises too high.

Integrated reverse battery protection circuit for an external MOSFET switch

A system for controlling a plurality of load devices includes a high-side system operative to source current relative to at least two associated outputs. A low-side system is operative to sink current relative to a plurality of associated inputs. A control system controls the high-side system and the low-side system according to a multiplexing scheme that is operative to provide current to selected load devices of the plurality of load devices connected between the associated outputs and the associated inputs. The system can be implemented as an integrated circuit for driving the plurality of loads, which can include LED's.

System and method for driving a plurality of loads

A current control device for driving LED devices uses a switched-mode current control loop inside of an output intensity low-frequency pulse width modulation (PWM) control loop. This allows separate control of current level (for accurate light wavelength output) and light intensity. The current control device requires only one switch to regulate current level, and no other switches for the intensity control. This allows lower parts count for greater reliability and lower system cost.

Current control device for driving LED devices

A programmable voltage regulator configurable for reverse blocking and double power density is disclosed herein. The programmable voltage regulator includes an error amplifier that couples to receive a reference voltage. A first NMOS pass transistor connects between an auxiliary voltage input node and the output terminal of the voltage regulator, wherein the first NMOS pass transistor is biased by the output of the error amplifier. Connected between the source of the first NMOS pass transistor and the second input of the error amplifier, a feedback network provides feedback for the voltage regulator. A second NMOS pass transistor connects between the first power supply and the auxiliary voltage input node. Furthermore, an independent node control circuit biases the second NMOS pass transistor such that in a first mode of operation, a first control signal input is operable to receive a signal for controlling the second NMOS pass transistor during reverse battery condition. In a second mode of operation, independent node control circuit includes a second control signal input that is operable to couple to the output terminal of the error amplifier while simultaneously the first power supply rail is operable to couple to the output terminal of the voltage regulator to provide double power density.

Programmable voltage regulator configurable for double power density and reverse blocking

A switch mode controller circuit includes: a hysteretic comparator HYST_COMP for monitoring an output of a switch mode circuit; a standard comparator PHASE_COMP for monitoring a phase of the switch mode circuit; a logic block having a first input coupled to a clock signal generator Oscillator, a second input coupled to an output of the hysteretic comparator HYST_COMP, and a third input coupled to an output of the standard comparator PHASE_COMP, wherein the logic block generates switching cycles based on a fixed ON/OFF time during a first part of a cycle and based on a hysteretic control during a second part of the cycle.

Switch mode regulator controller using hybrid technique

An integrated solution to power management and distribution on a power bus, such as needed for an IEEE 1394 compliant expansion board. The integrated circuit includes a uni-directional switch on the input and one or more bi-directional switches on one or more outputs. Current can flow from the system power supply to any connected peripherals via the uni-directional switch and bi-directional switches, or can flow from the peripheral having the highest voltage power supply to the other peripherals via the bi-directional switches, but current will not flow back to the main system because of the unidirectional switch connected to the system power supply. Over-current conditions are quickly detected and the bi-directional switch is opened to prevent damage or over-heating. The switches are preferably fabricated as power FETs using NMOS technology. Several integrated circuits can be cascaded together to accommodate multiple peripherals.

System and method of regulating the distribution of power throughout a system through the use of uni-directional and bi-directional switches

The regulator circuit with an auxiliary boundary regulator that provides enhanced transient response includes: an upper comparator having a first input coupled to a feedback node and a second input coupled to a first reference voltage node V_HIGH; a lower comparator having a first input coupled to the feedback node and a second input coupled to a second reference voltage node V_LOW; a first switching device having a control node coupled to an output of the upper comparator ; a second switching device having a control node coupled to an output of the lower comparator ; an inductor having a first end coupled to the first and second switching devices and , and a second end coupled to an output node Vout; and a feedback circuit and coupled between the output node Vout and the feedback node. This circuit provides a precise, quiet, linear regulator that provides a tightly regulated output with a fast regulator working in parallel to ensure that the output voltage stays within an acceptable boundary.

Auxiliary boundary regulator that provides enhanced transient response

A control circuit ( ) for a switch mode power converter having precise control of amplitude and frequency that does not exhibit overshoot error nor undershoot error during a fast charge cycle nor a fast discharge cycle, respectively. In a first embodiment, the control circuit ( ) does not exhibit undershoot error during a fast discharge cycle. The control circuit ( ) comprises an oscillator ( ) for providing a periodic carrier signal comprising a sawtooth wave output signal (V ). The oscillator ( ) includes a capacitor (C ) charged and discharged to the power supply voltage (V ) to provide the sawtooth wave output signal (V ). In addition, the oscillator ( ) includes a switching circuit ( ) coupled to the reference voltage level (V ). The control circuit ( ) further includes a gain circuit ( ) having a reference voltage input (V ), voltage input (V ) and an output (Out). The reference voltage input (V ) receives the reference voltage(V ). The voltage input (V ) connects to the capacitor (C ). The output (Out) of the gain circuit ( ) connects to the switching circuit ( ) to provide feedback proportional to the analog error signal related to the difference between the sawtooth wave output signal (V ) and the predetermined reference voltage level (V ).

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Richardson, TX, United States of America

Sanmukh Makan Patel