Linear Technology Patent Grants

Controller area network bus transmitter with complementary source follower driver

Granted: October 11, 2016
Patent Number: 9467303
A Controller Area Network (CAN) driver (a transmitter) includes a conventional main driver having an open drain first driver MOSFET, for pulling up a first conductor of a bus in a dominant state, and an open drain second driver MOSFET, for pulling down a second conductor of the bus in the dominant state. Since it is difficult to perfectly match the driver MOSFET characteristics for conducting exactly equal currents during turning on and turning off, significant common mode fluctuations…

LDO regulator powered by its regulated output voltage for high PSRR

Granted: September 27, 2016
Patent Number: 9454168
In an LDO regulator, two feedback loops are created. The first feedback loop includes a high power PNP bipolar power transistor connected in series between the input voltage Vin terminal and the output voltage Vout terminal. The first feedback loop includes a first error amplifier that controls a drive transistor to drive the base of the power transistor such that Vout matches a set voltage Vset. This first feedback loop circuitry uses an operating voltage (the upper rail voltage) that…

Address translation in I2C data communications system

Granted: September 20, 2016
Patent Number: 9448960
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…

Exposed, solderable heat spreader for integrated circuit packages

Granted: August 30, 2016
Patent Number: 9431319
An integrated circuit package may include a semiconductor die, a heat spreader, and encapsulation material. The semiconductor die may contain an electronic circuit and exposed electrical connections to the electronic circuit. The heat spreader may be thermally-conductive and may have a first outer surface and a second outer surface substantially parallel to the first outer surface. The first outer surface may be affixed to all portions of a silicon side of the semiconductor die in a…

PD in PoE system having redundant PSE channel inputs

Granted: August 16, 2016
Patent Number: 9419807
A Powered Device (PD) in a PoE system has two input channels, each being coupled to a separate Power Sourcing Equipment (PSE) for increased reliability. A first PD controller is coupled to the first channel to perform hand-shaking and closes a first Power Good (PWRGD) switch when the PoE voltage is detected on the first channel. A second PD controller is coupled to the second channel to perform hand-shaking and closes a second PWRGD switch when the PoE voltage is detected on the second…

System and method for providing programmable synchronous output delay in a clock generation or distribution device

Granted: July 19, 2016
Patent Number: 9397668
A clock frequency division circuit receives delay value, synchronization signal, and external clock signal of a given frequency. The clock division circuit includes (a) a decode circuit receiving delay value and providing set of initial count values; (b) one or more counters each receiving input clock signal derived from the external clock signal and providing frequency divided output signal having a frequency a fraction of the given frequency, and each receiving a corresponding one of…

Low-voltage analog variable gain amplifier with enhanced linearity

Granted: July 12, 2016
Patent Number: 9391577
In a variable gain amplifier, a base of a bipolar first transistor receives a first differential input signal. The emitter of the first transistor is connected in series between a first resistor and a MOSFET coupled to ground. An output of the amplifier is a current through the collector. The conductivity of the MOSFET controls a gain of the amplifier. A bipolar second transistor receives a second differential input signal, and the second transistor provides a modulated gate voltage to…

Rapid power up of Power Over Ethernet equipment system

Granted: June 28, 2016
Patent Number: 9377794
A Power Over Ethernet (PoE) system includes Power Sourcing Equipment (PSE) providing data and voltage over Ethernet wires to a Powered Device (PD). Instead of the conventional detection and classification routine being performed every time the system is powered up, the pertinent data to determine whether to apply PoE to the PD is stored in a memory in the PSE. The memory is accessed by a controller in the PSE when the PSE is powered up. Therefore, a time-consuming detection and…

Level-shifting amplifier

Granted: June 21, 2016
Patent Number: 9374050
A differential amplifier may, when connected to a positive or negative supply voltage and to a ground voltage, provide a differential pair of outputs signals at a differential output that are an amplification of a differential pair of input signals at a differential input. A differential input stage may receive the differential pair of input signals from the differential input and may include a first transistor associated with one of the input signals and a second transistor associated…

Converting time-encoded signal into analog output

Granted: June 21, 2016
Patent Number: 9374105
A converter may generate an analog output that is representative of a time-encoded signal. The circuit may include an input port receiving the time-encoded signal; a time-encoded to digital converter coupled to the input port; and a digital-to-analog converter coupled to the time-encoded to digital converter.

Boost then floating buck mode converter for LED driver using common switch control signal

Granted: May 24, 2016
Patent Number: 9351352
A converter has a boost portion and a buck portion. The boost portion supplies a boosted voltage and includes a first inductor having a first end coupled to the input terminal, a first switch coupled to a second end of the first inductor to charge the first inductor when the first switch is in its on-state, and a first capacitor for being charged to the boosted voltage. The buck portion supplies an output voltage to a load that is less than the boosted voltage and includes a second…

Voltage generator with current source compensated for an error current operable over a wide voltage range

Granted: May 24, 2016
Patent Number: 9348347
In one embodiment, a regulator circuit for generating a regulated output voltage Vout has an error amplifier using a pair of bipolar transistors at its front end. The error amplifier compares the regulated output voltage to a reference voltage Vref. A precision current source draws a first current through a user-selected set resistance to generate the desired Vref. The regulator circuit controls a power stage to cause Vout to be equal to Vref. The base current into one of the bipolar…

Trimming gain and CMMR in difference amplifier

Granted: May 10, 2016
Patent Number: 9337792
A multistage amplifier may include a multistage amplifier circuit and a resistive voltage divider network. The multistage amplifier circuit may have multiple transconductance input stages, each of which may have differential inputs and an adjustable tail current input that controls the amount of the transconductance of the input stage. The resistive voltage divider network may control the closed loop gain of the multistage amplifier circuit and include multiple resistors that provide…

Power converter for generating both positive and negative output signals

Granted: May 10, 2016
Patent Number: 9337731
A power converting system produces an input signal regulated with respect to an input signal. The power converting system has a first inductive element having a first node coupled to an input node, and a second inductive element having a first node coupled to an output node. A first switching element is coupled to a second node of the first inductive element. A first capacitive element is coupled between the second node of the first inductive element and of the second inductive element.…

Analog-to-digital converter

Granted: May 3, 2016
Patent Number: 9331709
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…

High-frequency RMS-DC converter using chopper-stabilized square cells

Granted: May 3, 2016
Patent Number: 9330283
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 polarity independent step-up converter capable of operating under ultra-low input voltage condition

Granted: April 26, 2016
Patent Number: 9325250
Apparatus and method for a polarity independent step-up converter capable of operating with ultra low input voltage. The step-up converter as disclosed herein receives an input source having a variable polarity and includes a first core circuit coupled to the input source and an output of the step-up converter and a second core circuit coupled to the input source and the output of the step-up converter. The first core circuit is configured to be active for a first input voltage polarity…

Broadband integrated RF/microwave/millimeter mixer with integrated balun(s)

Granted: April 12, 2016
Patent Number: 9312815
A broadband radio frequency, microwave, or millimeter mixer system may include a balun and a mixer. The balun may have an unbalanced port; a balanced port; a first and a second inductor tightly and inversely magnetically coupled to one another; and a third inductor which is not magnetically coupled to the first or the second inductors. The mixer may be connected to the balanced port of the balun. The balun, including its three inductors, and the mixer may all be integrated onto a single…

Auto resonant driver for wireless power transmitter sensing required transmit power for optimum efficiency

Granted: April 5, 2016
Patent Number: 9305700
An auto-resonant driver for a transmitter inductor drives the inductor at an optimal frequency for maximum efficiency. The transmitter inductor is magnetically coupled, but not physically coupled, to a receiver inductor, and the current generated by the receiver inductor is used to power a load. The system may be used, for example, to remotely charge a battery (as part of the load) or provide power to motors or circuits. A feedback circuit is used to generate the resonant driving…

Exponential ROM table tuning using trim for frequency agile analog filters

Granted: April 5, 2016
Patent Number: 9306531
A tunable and trimmable analog filter may include a tunable analog filter and a trimming circuit. The tunable analog filter may set the frequency of a characteristic of the tunable analog filter based on a digital tuning signal that is indicative of a desired frequency of the characteristic. However, the tunable analog filter may contain components having values that deviate from specified values due to var during manufacture of the tunable analog filter. The value deviations can cause…