Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to, the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: A distributed system for driving strings of series-connected LEDs for backlighting, display and lighting applications includes multiple intelligent satellite LED driver ICs connected to a an interface IC via serial bus. The interface IC translates information obtained from a host microcontroller into instructions for the satellite LED driver ICs pertaining to such parameters as duty factor, current levels, phase delay and fault settings. Fault conditions in the LED driver ICs can be transmitted back to the interface IC. An analog current sense feedback system which also links the LED driver ICs determines the supply voltage for the LED strings.

Abstract: Thermal transfer from a silicon-on-insulator (SOI) die is improved by mounting the die in a bump-on-leadframe manner in a semiconductor package, with solder or other metal bumps connecting the active layer of the SOI die to metal leads used to mount the package on a printed circuit board or other support structure.

Abstract: A method for controlling a switching voltage regulator that includes generating a feedback voltage that is proportional to the output voltage of the voltage regulator; generating a voltage proportional to the duty-cycle of the inductor charging and discharging phases as a function of the difference between the feedback voltage and a reference voltage; and adding a dominate pole and two zeros to the function used to generate the voltage proportional to the duty-cycle of the inductor charging and discharging phases.

Abstract: A freewheeling MOSFET is connected in parallel with the inductor in a switched DC/DC converter. When the freewheeling MOSFET is turned on during the switching operation of the converter, while the low-side and energy transfer MOSFETs are turned off, the inductor current circulates or “freewheels” through the freewheeling MOSFET. The frequency of the converter is thereby made independent of the lengths of the magnetizing and energy transfer stages, allowing far greater flexibility in operating and converter and overcoming numerous problems associated with conventional DC/DC converters. In one embodiment the freewheeling MOSFET is an N-channel MOSFET with its body connected to circuit ground and not shorted to either its source or its drain.

Abstract: A multiple output DC-to-DC voltage converter using a new time-multiplexed-capacitor converter algorithm and related circuit topologies is herein disclosed. One embodiment of this invention includes a flying capacitor, a first output node, a second output node, and a switching network. The switching network configured to provide the following modes of circuit operation: 1) a first mode where the positive electrode of the flying capacitor is connected to an input voltage and the negative electrode of the flying capacitor is connected to ground; 2) a second mode where the negative electrode of the flying capacitor is connected to the input voltage and the positive electrode of the flying capacitor is connected to the first output node; and 3) a third mode where the positive electrode of the flying capacitor is connected to ground and the negative electrode of the flying capacitor is connected to the second output node.

Abstract: A low voltage current mirror design is used to control a high voltage boost converter. A high amperage reference current emanating from a high voltage inductor based DC-to-DC boost converter is mirrored to a low amperage output current. On-chip CMOS elements are used to measure and manipulate the output current, eliminating the need for a high precision, low resistance, external resistor. The measured and manipulated current is used to control the PWM duty cycle of an inductor based DC-to-DC boost converter, allowing for a lower cost solution in a high voltage, high current situation.

Abstract: A multi-output dual polarity inductive boost converter includes an inductor, a first output node, a second output node, and a switching network, the switching network configured to provide the following modes of circuit operation: a first mode where the positive electrode of the inductor is connected to an input voltage and the negative electrode of the inductor is connected to ground; 2) a second mode the negative electrode of the inductor is connected to ground and the positive electrode of the inductor is connected in sequence to one or more of the fourth and fifth output nodes; and 3) a third mode where the positive electrode of the inductor is connected to the input voltage and the negative electrode of the inductor is connected in sequence to one or more of the first, second and third output nodes.

Abstract: An integrated circuit contains a current sink that is used to control a channel of varying forward voltage, with a goal of maintaining a minimally sufficient voltage across the current sink. A target voltage for the current sink return is determined, and a switched inductor is used to maintain said voltage. Various target determination schemes are possible, and various enhancements improve startup time, efficiency, and effectiveness.

Abstract: A switching regulator that practices the current invention includes a high-side switch M1 connected between an input voltage and a node LX. A low-side switch is connected between the node LX and ground. An inductor L is connected between LX and an output node (VOUT). A filtering capacitor connects VOUT to ground. The switching regulator has two distinct operational phases. During the first operational phase, the high-side switch is OFF and the low-side switch is ON. During the second operational phase, the high-side switch is ON and the low-side switch acts as a current source. During transitions between the second and first operational phases, the low-side switch is controlled to momentarily decrease the regulated drain-to-source current.

Abstract: A SEPIC converter with over-voltage protection includes a high-side inductor that connects a node Vw to a node Vx. The node Vx is connected, in turn to ground by a power MOSFET. The node Vx is also connected to a node Vy by a first capacitor. The node Vy is connected to ground by a low-side inductor. A rectifier diode further connects the node Vy and a node Vout and an output capacitor is connected between the node Vout and ground. A PWM control circuit is connected to drive the power MOSFET. An over-voltage protection MOSFET connects an input supply to the PWM control circuit and the node Vw. A comparator monitors the voltage of the input supply. If that voltage exceeds a predetermined value Vref the comparator output causes the over-voltage protection MOSFET to disconnect the node Vw and the PWM control circuit from the input supply.

Abstract: Devices, such as mobile devices, may be exposed to short circuit and output overload events. To protect against such events, mobile devices typically include current limit circuits. Some current limit circuits may involve user programmable function. User programmable function may need accurate current limit detectors. Various embodiments of the present invention include devices and methods for detecting one or more programmed current limits. Some embodiments allow for a user application to select among parallel or serial configurations of current detection circuitry. Each such configuration may include multiple resistive devices of different resistive values.

Abstract: A transistor is formed inside an isolation structure which includes a floor isolation region and a trench extending from the surface of the substrate to the floor isolation region. The trench may be filled with a dielectric material or may have a conductive material in a central portion with a dielectric layer lining the walls of the trench.

Abstract: A transistor is formed inside an isolation structure which includes a floor isolation region and a trench extending from the surface of the substrate to the floor isolation region. The trench may be filled with a dielectric material or may have a conductive material in a central portion with a dielectric layer lining the walls of the trench.

Abstract: Devices, such as mobile devices, may be exposed to short circuit and output overload events. To protect against such events, mobile devices typically include circuitry to limit currents so as not to exceed a pre-programmed current limit. Various embodiments of the present invention include devices and methods for detecting pre-programmed current limits and for limiting currents in response to such detection. In some embodiments, both the current limit detector and the current limit controller circuitry include scaled current switches. The scaling may be substantially similar between the programmed-current limit detector and the current limit controller circuitry.

Abstract: A stereo class-D audio system includes a first die including four monolithically integrated NMOS high-side devices and a second a second die including four monolithically integrated PMOS low-side devices. The audio system also includes a set of electrical contacts for connecting the high and low-side devices to components within the a stereo class-D audio system, the set of electrical contacts including at least one supply contact for connecting the drains of the high-side devices to a supply voltage (Vcc) and at least one ground contact for connecting the drains of the low-side devices to ground, the electrical contacts also including respective contacts for each source of the high and low-side devices allowing the source of each high-side device to be connected to the source of a respective low-side device to form two H-bridge circuits.

Abstract: An operational transconductance amplifier used in conjunction with a multiple chip voltage feedback technique allows multiple strings of LEDs and current sinks to be efficiently powered by a simple feedback oriented voltage regulator within an appliance. A connected series of differential amplifiers or multiplexors are used to monitor the voltages between the connected LEDs and the current sinks, in order to progressively determine the lowest voltage. The operational transconductance amplifier compares this voltage to a reference voltage and injects or removes current from the feedback node of a voltage regulator, thereby altering the voltage present at the feedback node. This causes the voltage regulator to adjust its output, ensuring that the current sinks of the LED strings have adequate voltage with which to function, even as the LEDs have different forward voltages and the strings are asynchronously enabled and disabled.

Abstract: To avoid shorts between adjacent die pads in mounting a multi-die semiconductor package to a printed circuit board (PCB), one of the die pads is embedded in the polymer capsule, while the other die pad is exposed at the bottom of the package to provide a thermal escape path to the PCB. This arrangement is particularly useful when one of the dice in a multi-die package generates more heat than another die in the package.

Abstract: Processes for forming isolation structures for semiconductor devices include forming a submerged floor isolation region and a filed trench which together enclose an isolated pocket of the substrate. One process aligns the trench to the floor isolation region. In another process a second, narrower trench is formed in the isolated pocket and filled with a dielectric material while the dielectric material is deposited so as to line the walls and floor of the first trench. The substrate does not contain an epitaxial layer, thereby overcoming the many problems associated with fabricating the same.