Linear Technology Patent Grants

Logarithmic scale analog to digital converter for wide dynamic range avalanche photodiode current companding

Granted: October 6, 2020
Patent Number: 10794761
An electronic circuit comprises an analog-to-digital converter (ADC) circuit. The ADC circuit includes a pre-amplifying transistor and a quantizer circuit. The pre-amplifying transistor includes a base, an emitter and a collector. The pre-amplifying transistor is configured to receive an input voltage at the base that varies logarithmically; and produce an output voltage at the collector according to a comparison of a reference voltage and a difference between the input voltage and a…

Methods and systems of reducing charge pump substrate noise

Granted: August 18, 2020
Patent Number: 10749429
Methods and systems of reducing a substrate noise in a charge pump having a flying capacitor are provided. An input node of the flying capacitor is pre-charged at a first slew rate. The input node of the flying capacitor is charged at a second slew rate that is faster than the first slew rate. The input node of the flying capacitor is pre-discharged at a third slew rate. The input node of the flying capacitor is discharged at a fourth slew rate that is faster than the first slew rate.

Notch filter for ripple reduction

Granted: July 21, 2020
Patent Number: RE48112
A notch filter is controlled synchronously with a chopper to filter out chopping ripple. In one embodiment, the notch filter is coupled to the differential output of the chopper and includes a sampling capacitor, a hold capacitor, and a second set of switches between the sampling capacitor and the hold capacitor. The second set of switches is temporarily closed once per chopper switching cycle to transfer charge from the sampling capacitor to the hold capacitor such that the ripple from…

Current sensing method for hybrid converters

Granted: June 23, 2020
Patent Number: 10693373
A hybrid power converter includes a switching circuit, an LC circuit, and a detection circuit. The switching circuit includes three or more switching transistors in series that may turn on or off according to a switching cycle to generate a series of voltage pulses at an output port across one of the switching transistors. The LC circuit may be coupled to the output port of the switching circuit to receive the series of pulses and to generate an inductor current in the LC circuit. The…

Trans-impedance amplifier with fast overdrive recovery

Granted: June 16, 2020
Patent Number: 10686412
A high-speed low-noise trans-impedance amplifier (TIA) with fast overdrive recovery is suitable for use in light detection and ranging (LIDAR) receivers.

Load current feedforward schemes for current-mode controlled power converters

Granted: June 16, 2020
Patent Number: 10686379
A switching power converter circuit comprises an inductor arranged to receive input energy from an input circuit node; a switch circuit coupled to the inductor; a load current sensing circuit element coupled to a regulated circuit node and an output circuit node; a compensation circuit coupled to a compensation circuit node; a control circuit coupled to the compensation circuit node and the switch circuit, the control circuit configured to modulate activation of the switch circuit to…

Chopper amplifiers with high pass filter for suppressing chopping ripple

Granted: June 2, 2020
Patent Number: 10673389
Chopper amplifiers with high pass filters for suppressing chopping ripple are provided herein. In certain embodiments, a chopper amplifier includes an input chopping circuit, an amplification circuit, a low frequency content detection circuit, and an output chopping circuit electrically connected in a cascade. The low frequency content detection circuit operates in combination with a transconductance or other gain circuit as a high pass filter that filters input offset voltage and/or low…

Balancing charge pump circuits

Granted: May 26, 2020
Patent Number: 10666135
Methods and systems of controlling a switched capacitor converter are provided. Upon determining that a voltage across a flying capacitor is above a first threshold, a first current is drawn from a first terminal of the flying capacitor by a first current source, and a second current is provided to a second terminal of the flying capacitor by a second current source. Upon determining that the voltage across the flying capacitor is below a second threshold, the first current is provided…

Simultaneous power injection in power over ethernet system

Granted: May 12, 2020
Patent Number: 10652035
In a PoE system, DC power is transmitted over two wire pairs. The primary winding of an isolation transformer is connected across the differential I/O terminals of a first PHY (a transceiver). A positive voltage output of a power supply is connected to a center tap of the secondary winding, and the secondary winding is coupled across a first wire pair. In this way, differential data and DC power is supplied to the first wire pair. A CMC is connected between the secondary winding and an…

Power over data lines system using split or coupled CMCs and DMCs for coupling DC voltage and attenuating common mode noise

Granted: May 12, 2020
Patent Number: 10652050
A PoDL system conducts differential data and DC power over the same wire pair, and various DC coupling techniques are described that improve DC voltage coupling while attenuating AC common mode noise. Pairs of differential mode chokes (DMCs) are used to share current supplied by a power supply. In one embodiment, one DMC is coupled to the line side of a common mode choke (CMC), and one DMC is coupled to the PHY side of the CMC. The line-side DMC has windings that are loosely magnetically…

Transceiver utilizing isolated signaling and concealed isolated power to attain high common mode working voltage and tolerance

Granted: May 12, 2020
Patent Number: 10651894
A transceiver capable of common mode operating range and output voltage tolerance set by an isolation boundary and not limited by the device type used in the circuitry. The subject technology is a powered isolated transceiver, where the isolated generated supply and ground nodes are concealed and thus do not participate in tests that stress electrostatic discharge (ESD)/electrical overstress (EOS) or voltage tolerance. The architecture of the subject technology has the advantage of…

Regulator light load control techniques

Granted: May 5, 2020
Patent Number: 10644591
Techniques for operating a power supply under light load conditions are provided. In an example, a frequency of an oscillator can be adjusted based on a feedback signal indicative of a voltage error of the power supply when the feedback signal falls below a first threshold. In certain examples, a peak inductor current command can be kept constant and a slope compensation ramp can be based on the frequency of the oscillator when the feedback signal falls below the first threshold. In some…

Ripple monitoring

Granted: May 5, 2020
Patent Number: 10641837
A ripple monitoring circuit may generate information indicative of a failing component in a power supply. At least one input may receive a ripple signal from the power supply that has a ripple component. A quantization circuit may repeatedly quantize the amplitude of the ripple component. A ripple amplitude statistics counter bank may count and store the number of times that different quantized amplitudes or different ranges of quantized amplitudes of the ripple component occurred. A…

Spread spectrum for switch mode power supplies

Granted: April 28, 2020
Patent Number: 10637254
A switch mode power supply may utilize a switching signal to control one or more power switches in the switch mode power supply. A switch mode power supply controller may generate and/or control this switching signal. The controller may reduce the peak spectral noise of the switch mode power supply by varying the instantaneous switching frequency at a constant slew rate magnitude that changes sign at random times. The instantaneous switching frequency may be controlled by a signal that…

Open circuit-based Rx power limiter for wireless power transfer

Granted: April 7, 2020
Patent Number: 10615626
A wireless power transfer system may wirelessly transmit and receive power. A transmitting coil may wirelessly transmit the power. A receiving coil may be magnetically but wirelessly coupled to the transmitting coil and may wirelessly receive the power and generate an AC input voltage. A rectifier may rectify the AC input voltage. A capacitance may filter the rectified AC input voltage. An electronic switch may be connected in series between the rectified AC input voltage and an output.…

Wilkinson combiner with coupled inductors

Granted: March 31, 2020
Patent Number: 10608313
A power divider/combiner circuit with coupled inductors is provided. With coupled inductors, the new circuit topology exhibits broader bandwidth for insertion loss, port matching and isolation compared with traditional power divider/combiner circuit topologies. The coupled inductors can be implemented for single-stage low-pass networks, multi-stage low-pass networks, or multi-stage wide-band networks. For example, the power divider/combiner circuit includes a first coupled inductor…

Monitoring of channel stability and interference in wireless networks

Granted: March 17, 2020
Patent Number: 10595216
The stability of a channel in a wireless network is evaluated at a node. Upon transmitting a packet from the node on a network channel, a first counter associated with the channel is incremented. Upon receiving an acknowledgment packet responsive to the transmitted packet, a second counter associated with the channel is incremented. A stability metric for the channel is computed based on values stored in the first and second counters. Additionally, interference on a channel of the…

Power over data lines system using pair of differential mode chokes for coupling DC voltage and attenuating common mode noise

Granted: March 17, 2020
Patent Number: 10594519
In a Power over Data Lines (PoDL) system that conducts differential data and DC power over the same wire pair, various DC coupling techniques are described that improve DC voltage coupling while attenuating AC common mode noise. Pairs of differential mode chokes (DMCs) are used to share current supplied by a single phase or multi-phase power supply. In one embodiment, one DMC is coupled to the line side of a common mode choke (CMC), and one DMC is coupled to the PHY side of the CMC. The…

Power over data lines system with accurate and simplified cable resistance sensing

Granted: March 17, 2020
Patent Number: 10594367
In a PoDL system, where DC power and differential data are supplied over the same conductors between a PSE and a PD, a low-power test is first performed to determine the conductor resistance. The PSE and PD are connected to the conductors via DC-coupling inductors that block the data signals. Such inductors have a DC resistance (DCR). To avoid the DCR of the PD inductors being included in the resistance test of the conductors and to avoid the requirement of additional pins for kelvin…

Exposed solderable heat spreader for flipchip packages

Granted: March 10, 2020
Patent Number: 10586757
A flipchip may include: a silicon die having a circuit side with solder bumps and a non-circuit side; a leadframe attached to the solder bumps on the circuit side of the silicon die; a heat spreader attached to the non-circuit side of the silicon die; and encapsulation material encapsulating the silicon die, a portion of the leadframe, and all but one exterior surface of the heat spreader. The leadframe may have NiPdAu plating on the portion that is not encapsulated by the encapsulation…