Linear Technology Patent Applications

ADDRESS TRANSLATION IN 12C DATA COMMUNICATIONS SYSTEM

Granted: September 18, 2014
Application Number: 20140281080
A novel readdressing circuit is provided for supporting data communications over a data line and a clock line between at least one master device and multiple slave devices. For example, the master device and the multiple slave devices may be configured to communicate over an I2C bus including the data line and the clock line. The readdressing circuit has a data input node for receiving a data signal transferred over the data line and including an address word produced by the master…

METHODS AND SYSTEMS FOR CONTROL OF DC-DC CONVERTERS

Granted: September 18, 2014
Application Number: 20140268909
Switching regulator methods and systems for supplying output current at a regulated voltage level to a load. The regulator has a primary side that is galvanically isolated from a secondary side. The regulator includes a transformer having a primary winding on the primary side and a secondary winding on the secondary side, coupled to a load. A switch, coupled to the primary winding, controls current flow through the primary winding. A first feedback control loop, responsive only to…

OUTPUT STAGE WITH FAST FEEDBACK FOR DRIVING ADC

Granted: September 18, 2014
Application Number: 20140266840
A driver for an analog-to-digital converter (ADC) has an overall feedback loop between its input and its output for maintaining overall accuracy, and a much faster feedback loop in its output stage that quickly compensates for output transients before the overall feedback loop can substantially react to the transients. Output voltage transients are created by the intermittent capacitive load of the ADC. The fast feedback loop can be made very fast since there are only a few components in…

TRANSLINEAR SLEW BOOST CIRCUIT FOR OPERATIONAL AMPLIFIER

Granted: September 18, 2014
Application Number: 20140266435
A method of improving the slew rate of an amplifier is described where a differential pair of transistors receives a differential first control signal and second control signal. The tail current for the transistors is provided by a tail current regulator. The same control signals are applied to a slew boost controller, whose output increases as the differential between the control signals increase. The tail current regulator generates a bias signal that sets a minimum tail current. The…

BIPOLAR TRANSISTOR WITH LOWERED 1/F NOISE

Granted: September 18, 2014
Application Number: 20140266393
In a bipolar transistor, a thin gate oxide, preferably less than 600 ?, is formed over the base surface region between the emitter and collector. A conductive gate, such as doped polysilicon, is then formed over the gate oxide and biased at the emitter voltage. In the example of a PNP transistor, when the emitter is forward biased with respect to the base to turn the transistor on, the gate is at a positive potential relative to the base. This causes the holes in the base conducting the…

ROTATING 3-WIRE RESISTANCE TEMPERATURE DETECTION EXCITATION CURRENT SOURCES AND METHOD

Granted: August 28, 2014
Application Number: 20140241400
In a temperature sensing circuit, a method for measuring a resistance of a RTD device to sense temperature includes (a) connecting a first terminal of the RTD device to a first current source and connecting a second terminal of the RTD device to a second current source; (b) measuring a first voltage across the RTD device; (c) connecting the second terminal of the RTD device to the first current source and connecting the first terminal of the RTD device to the second current source; (d)…

SYNCHRONIZED CHARGE PUMP-DRIVEN INPUT BUFFER AND METHOD

Granted: August 28, 2014
Application Number: 20140240035
An integrated circuit includes (a) an analog-to-digital converter operated according to a first clock signal; and (b) a charge pump circuit providing a negative power supply voltage to the integrated circuit, the charge pump circuit being operated according to a second clock signal having a frequency that is different from a frequency of the first clock signal, such that a noise level introduced by the charge pump into the analog-to-digital converter is less than the average noise level…

THERMOCOUPLE OPEN-CIRCUIT DETECTION CIRCUIT AND METHOD

Granted: August 28, 2014
Application Number: 20140239970
A method for detecting an open-circuit in an external thermocouple network includes these steps: (a) injecting a current pulse of a predetermined duration into the external thermocouple network; and (b) measuring the voltage across the pair of terminals after a time period following the predetermined duration. In one example, the time period is sufficiently long to allow the current pulse to dissipate from the external thermocouple circuit when a thermocouple in the external thermocouple…

HIGH-FREQUENCY RMS-DC CONVERTER USING CHOPPER-STABILIZED SQUARE CELLS

Granted: August 21, 2014
Application Number: 20140233288
An RMS-DC converter includes a chopper-stabilized square cell that eliminates offset, thus enabling high-bandwidth operation. The chopper-stabilized offset requires only a small portion of the circuitry (i.e., a single component square cell) which operates at high frequencies, and is amenable to using high-bandwidth component square cells. Using the chopping technique minimizes required device sizes without compromising an acceptable square cell dynamic range, thereby maximizing the…

METHOD AND SYSTEM FOR MEASURING THE RESISTANCE OF A RESISTIVE STRUCTURE

Granted: July 10, 2014
Application Number: 20140191768
Method and system for measuring the resistance of a resistive structure having at least three nodes. A first calibration signal is determined by measuring a voltage at an output of the resistance structure when no calibration current is injected into a third node between the first and second nodes of the structure. A calibration current is then injected into the third node and a second calibration signal is determined. The absolute value of the difference between the first calibration…

LOW CURRENT DC-DC CONVERTER WITH INTEGRATED LOW CURRENT COULOMB COUNTER

Granted: July 10, 2014
Application Number: 20140191741
A power supply system includes a regulator circuit responsive to an input signal at the input node for producing an output signal at the output node at a desired level. The regulator circuit has a controller, an inductive element and a first switch coupled to the inductor element and controlled by the controller to produce the output signal. Also, the power supply system includes a Coulomb counter for producing a Coulomb count signal proportional to the number of Coulombs passing from…

POWER CONVERTER FOR GENERATING BOTH POSITIVE AND NEGATIVE OUTPUT SIGNALS

Granted: June 19, 2014
Application Number: 20140167715
A power converting system is responsive to an input signal to produce an output signal regulated with respect to the input signal. The power converting system has an input node for receiving the input signal, an output node for producing the output signal, and first and second inductive elements. The first inductive element has a first node coupled to the input node, the second inductive element has a first node coupled to the output node. A first switching element is coupled to a second…

FEED FORWARD CURRENT MODE SWITCHING REGULATOR WITH IMPROVED TRANSIENT RESPONSE

Granted: May 22, 2014
Application Number: 20140139198
A switching regulator circuit incorporates an offset circuit, connected in a control loop of the regulator circuit, that, in response to a signal indicating an imminent load current step, adjusts a duty cycle of a power switch for the current step prior to the regulator circuit responding to a change in output voltage due to the current step. In one embodiment, a load controller issues a digital signal shortly before a load current step. The digital signal is decoded and converted to an…

ANALOG-TO-DIGITAL CONVERTER

Granted: May 15, 2014
Application Number: 20140132432
An analog-to-digital converter (ADC) system and method. The ADC system in accord with one embodiment includes a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value, and a control circuit comprising a mismatch-shaping encoder. The control circuit is configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a…

ANALOG-TO-DIGITAL CONVERTER

Granted: May 15, 2014
Application Number: 20140132431
An analog-to-digital converter (ADC) system and method. The ADC system in accord with one embodiment includes a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value, and a control circuit comprising a mismatch-shaping encoder. The control circuit is configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a…

ANALOG-TO-DIGITAL CONVERTER SYSTEM AND METHOD

Granted: May 15, 2014
Application Number: 20140132430
An analog-to-digital converter (ADC) system and method. The ADC system in accord with one embodiment includes a sampling digital-to-analog converter configured to sample a combination of an analog signal value and an analog dither value, and a control circuit comprising a mismatch-shaping encoder. The control circuit is configured to sequentially apply a plurality of digital codes to the sampling digital-to-analog converter during an analog-to-digital conversion operation to derive a…

POLARITY CORRECTION BRIDGE CONTROLLER FOR COMBINED POWER OVER ETHERNET SYSTEM

Granted: May 8, 2014
Application Number: 20140129850
A system for combining power to a load in a Powered Device (PD) using Power Over Ethernet (PoE) receives power from a first channel and power from a second channel, via four pairs of wires. A MOSFET bridge for each channel is initially disabled. A bridge controller IC simultaneously senses all the voltages and controls the bridge MOSFETs. The bridge controller IC also contains a first PoE handshaking circuit. A second PoE handshaking circuit is external to the bridge controller IC and…

Magnetic Field Cancellation in Switching Regulators

Granted: April 24, 2014
Application Number: 20140111174
This invention uses new switching regulator structures to split single magnetic loops into multiple magnetic loops, with linked opposing magnetic fields, to cause a cancelling effect, resulting in a much lower overall magnetic field. This results in lower EMI. In one embodiment, synchronously switched transistors are divided up into parallel topside transistors and parallel bottomside transistors. The topside transistors are positioned to oppose the bottomside transistors, and bypass…

PWM CONTROL FOR LEDS WITH REDUCED FLICKER WHEN USING SPREAD SPECTRUM SWITCHING FREQUENCIES

Granted: April 24, 2014
Application Number: 20140111110
A technique to eliminate perceptible flickering by LEDs being dimmed by PWM pulses is disclosed. A controllable oscillator controls a switching frequency of a converter for supplying a regulated current or regulated voltage. The converter controls a first switch at a switching frequency. A varying second signal level is generated by a spread spectrum control (SSC) circuit for controlling the oscillator to vary the switching frequency during operation. A PWM dimming circuit generates a…

SYSTEM AND METHOD FOR INPUT VOLTAGE REGULATION OF SWITCH MODE SUPPLIES IMPLEMENTING BURST MODE OPERATION

Granted: April 10, 2014
Application Number: 20140097814
Switching regulator methods and systems are provided for supplying output current at a regulated voltage level to a load. Upon determining that the output current is not below a predetermined current threshold, the regulator is operated in a continuous mode. The input voltage is monitored. If the input voltage is not below a first input threshold level, the system remains in continuous mode. Otherwise, the system enters a burst mode in which the switch mode power supply is turned OFF,…