Hittite Microwave Corporation

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Hittite Microwave Norway As

Yalcin Alper Eken

Peter John Katzin

Savas Tokmak

Abdullah Celik

Alp Oguz

Celal Avci

Mehmet Arda Akkaya

Fatih Kocer

Shawn S Kuo

Ercan Kaymaksut

Atilim Ergul

Devrim Aksin

Tarik Cavus

Frank A Traut

Katzin Peter

Peter Katzin

Mechanisms for evaluating amplitude for current pulses provided to a transimpedance amplifier (TIA) for current levels beyond the linear range of the TIA where clipping circuit(s) may limit the input voltage of the TIA are disclosed. In one aspect, an example TIA arrangement includes a clipping arrangement that includes multiple clipping circuits. Each clipping circuit can be biased by different bias voltages such that the different clipping circuits are activated at different input current amplitudes. Different clipping circuits can have different impedances, which can result in different recovery time characteristics. With the multiple clipping circuits in clipping arrangements discussed herein, a saturated dynamic range of a TIA can be divided into sub-regions and different pulse widening characteristics for each region may be defined, which may enable determination of amplitude for current pulses provided to the TIA even for current levels beyond the linear range of the TIA.

Transimpedance amplifier with pulse widening

Laser driver designs that aim to reduce or eliminate the problem of fault laser firing are disclosed. Various laser driver designs presented herein are based on providing a current dissipation path that is configured to start providing a resistance for dissipating at least a portion, but preferably substantially all, of the negative current from the laser diode. Dissipating at least a portion of the negative current may decrease the unintentional increase of the voltage at the input to the laser diode and, therefore, reduce the likelihood that fault laser firing will occur. A control logic may be used to control the timing of when the current dissipation path is activated (i.e., provides the resistance to dissipate the negative current from the laser diode) and when it is deactivated.

Laser driver designs to reduce or eliminate fault laser firing

An example log power detector includes a gain or attenuation circuit and a detector circuit. The gain or attenuation circuit includes a plurality of gain or attenuation elements arranged in a sequence, each gain or attenuation element configured to generate an output signal that is an amplified or attenuated version of an input signal provided thereto. The detector circuit includes a plurality of detectors, each detector configured to receive the output signal from a different one of the gain or attenuation elements and to generate a signal indicative of a power of the received output signal. At least the last detector is configured to receive a DC offset signal that is different from a DC offset signal received by at least one other detector. Such a log detector may provide effective noise compensation to reduce errors caused by input noise, especially for low-power and/or high-frequency input signals.

Logarithmic power detector with noise compensation

Apparatus and methods for assisting a voltage regulator. In an example, a voltage regulator can include an error amplifier configured to compare a reference voltage with a representation of an output voltage of the voltage regulator, an output transistor coupled to a supply voltage and configured to receive an output of the error amplifier and to provide the output voltage, and an auxiliary-current circuit including a helper transistor having a terminal coupled to the output voltage, the helper transistor configured to turn on when the output voltage drops due to current demand from the load and to provide charge current to the load in addition to current provided by the output transistor.

Fast regulator architecture having transistor helper

Aspects of this disclosure relate to a receiver for a light detection and ranging system. The receiver includes a transimpedance amplifier that is operable in a linear mode for a range of power of light received by the receiver. The receiver can provide information about amplitude of the light outside of the range of power of the light for which the transimpedance amplifier operates in the linear mode. This information can be useful, for example, in identifying an object from which light received by the receiver was reflected.

High dynamic range transimpedance amplifier

A system and method for operating a high dynamic range analog front-end receiver for long range LIDAR with a transimpedance amplifier (TIA) include a clipping circuit to prevent saturation of the TIA. The output of the clipping circuit is connected via a diode or transistor to the input of the TIA and regulated such that the input voltage of the TIA remains close to or is only slightly above the saturation threshold voltage of the TIA. The regulation of the input voltage of the TIA can be improved by connecting a limiting resistor in series with the diode or transistor. A second clipping circuit capable of dissipating higher input currents and thus higher voltages may be connected in parallel with the first clipping circuit. A resistive element may be placed between the first and second clipping circuits to further limit the input current to the TIA.

High dynamic range analog front-end receiver for long range LIDAR

Embodiments of the present disclosure provide an optical range finder that includes a transimpedance amplifier (TIA) and a photodiode emulation circuitry for testing the TIA. The photodiode emulation circuitry may be coupled to an input port of the TIA and configured to receive one or more parameters specifying one or more characteristics of a test current signal to be provided to the TIA. The photodiode emulation circuitry may further be configured to provide the test current signal in accordance with the one or more parameters to the input port of the TIA while the photodiode is also coupled to the input port of the TIA.

Photo-diode emulator circuit for transimpedance amplifier testing

Disclosed herein are power detectors and methods for detecting the average power level of an RF input signal and the voltage envelope of the RF input signal. Also disclosed herein are linear envelope detectors and methods for detecting the voltage envelope of an RF input signal.

Envelope detector with bipolar triple-tail cells

RMS and envelope detector

An RF detector configured to provide two outputs, one being a function of the true RMS power level of an RF input signal, and the other being a function of the instantaneous/peak power of the RF input signal, normalized to the average power level. The RF detector includes a variable gain detection subsystem including a single detector or detector array that provides a representation of the power level of the RF input signal. The detector or detector array is common to both the RMS power detection channel and the instantaneous/peak power detection channel of the RF detector. A method of RF detection includes providing representations of the RF input signal at different gain levels, selecting one or more of the representations, and averaging the selected signals. The gain levels of the selected representations is adjusted to provide information about the average power level of the RF input signal.

RF detector with crest factor measurement

A mean square power detector in accordance with one or more embodiments includes a gain or attenuation circuit comprising a plurality of gain or attenuation elements arranged for generating a plurality of amplified or attenuated versions of a radio frequency (RF) input signal. The mean square power detector also includes a plurality of mean square detectors coupled to the gain or attenuation circuit. Each of the mean square detectors receives a different one of the plurality of amplified or attenuated versions of the RF input signal. Each of the plurality of mean square detectors generates an output signal representative of the mean square power of the RF input signal for a different input signal level range. A summing element is coupled to the plurality of mean square detectors for combining the output signals of the plurality of mean square detectors to generate a signal representative of the mean square or root mean square of the RF input signal.

Logarithmic mean-square power detector

A variable gain amplifier includes a plurality of amplification elements arranged to generate amplified representations of an RF input signal at a plurality of nodes. A plurality of controllable response elements each have an input coupled to a different one of the nodes to receive a different one of the amplified representations of the RF input signal. A scale factor generator is coupled to each of the controllable response elements. The scale factor generator receives a gain control signal and generates scale factor signals for varying the response of each of the controllable response elements such that as the scale factor generator sweeps through a full range of the gain control signal, the response of each of the controllable response elements is, in succession, increased smoothly to a peak and thereafter decreased smoothly to a lower level to produce a scaled output. A summing element is coupled to the controllable response elements for combining the scaled outputs of the controllable response elements to generate an output of the variable gain amplifier having a given gain range.

Logarithmic mean-square power detector with servo control loop

An active bias control circuit for an amplifier includes a low dropout regulator for providing a regulated voltage to provide an input current to the amplifier, and a current sense circuit responsive to the low dropout regulator for sensing a scaled down replica of the input current to the amplifier. An amplifier control circuit adjusts a control voltage to the amplifier in response to the sensed, scaled down replica of the input current to regulate the input current to the amplifier. A method for power up sequencing an amplifier for an active bias control circuit for the amplifier is also disclosed.

Active bias control circuit for an amplifier and method of power up sequencing the same

An active bias control circuit for an amplifier includes a switch responsive to a supply voltage for providing an input current to the input of the amplifier, and a current sense circuit coupled to the switch for sensing a scaled down replica of the input current to the amplifier. A first amplifier control circuit is responsive to the current sense circuit for adjusting a first control voltage to the amplifier in response to the sensed, scaled down replica of the input current to regulate the input current to the amplifier. Circuitry for power up sequencing an amplifier for an active bias control circuit for the amplifier is also disclosed.

Growing community of inventors

Istanbul, Turkey

Yalcin Alper Eken