Abstract: A transimpedance amplifier (TIA) can include an operational amplifier with a programmable compensation capacitor, such as can be used for compensating first transconductance stage of an operational amplifier circuit that can be used in a TIA configuration. This technique is particularly suitable, for example, for an Optical Time Domain Reflectometer (OTDR) application, which can use variable pulsewidth launch pulses. Based on the pulsewidth of such launch pulses, the bandwidth of an operational amplifier of the TIA can be adjusted, such as to decrease the signal and noise bandwidth when relatively wider pulses are to be used, to improve the noise performance for such wider pulses, and to increase the signal and noise bandwidth when relatively narrower pulses are to be used.

Abstract: An integrated circuit may include a substrate and a dielectric layer formed over the substrate. A plurality of p-type thermoelectric elements and a plurality of n-type thermoelectric elements may be disposed within the dielectric layer that are connected in series while alternating between the p-type and the n-type thermoelectric elements. The integrated circuit may include first and second substrates each having formed thereon a plurality of thermoelectric legs of a respective type of thermoelectric material. The first and second thermoelectric substrates also may have respective conductors, each coupled to a base of an associated thermoelectric leg and forming a mounting pad for coupling to a thermoelectric leg of the counterpart substrate.

Abstract: A method for detecting frequency mismatch in microelectromechanical systems (MEMS) gyroscopes is described. Detection of the frequency mismatch between a drive signal and a sense signal may be performed by generating an output signal whose spectrum reflects the physical characteristics of the gyroscope, and using the output signal to determine the frequency fC of the sense signal. The output signal may be generated by cross-correlating a random or pseudo-random noise signal with a response signal, where the response signal can be obtained by allowing the noise signal to pass through a system designed to have a noise transfer function that mimics the frequency response of the gyroscope. Since the noise signal is random or pseudo-random, cross-correlating the noise signal with the response signal reveals spectral characteristics of the gyroscope. To improve computational efficiency, the cross-correlation can be performed on demodulated versions of the noise signal and the response signal.

Abstract: A multiple-level driver circuit, such as for providing several different signals to a device under test (DUT) in an automated test system, can include multiple diode bridge circuits. In an example, a first diode bridge circuit is configured to receive a multiple-valued input voltage signal, having at least two different DC voltage signal levels, at an input node and, in response, to selectively provide a corresponding multiple-valued output voltage signal at an output node. The first diode bridge circuit can operate in a conducting and non-commutated state when it is used to selectively provide the multiple-valued output voltage signal at the output node.

Abstract: According to some aspects, a low-leakage switch is provided. In some embodiments, the low-leakage switch includes a plurality of pass transistors in series that selectively couple two ports of the low-leakage switch and a node biasing circuit coupled to a node between the plurality of pass transistors. In these embodiments, the node biasing circuit may adjust a voltage at the node to change the gate-to-source voltage of the pass transistors and, thereby, reduce the leakage current through the pass transistors when the low-leakage switch is turned off. The node biasing circuit may also include circuitry to reduce the leakage current introduced by the node biasing circuit into the node when the low-leakage switch is turned on.

Abstract: Techniques for limiting the output voltage of an amplifier without directly affecting an output current of the amplifier are provided. In an example, an amplifier can include a plurality of amplifier stages configured to receive an input voltage and to provide an output voltage as a function of the input voltage, and a comparator configured to receive a voltage limit and a representation of the output voltage of the amplifier, to adjust current at an input to a first amplifier stage of the plurality of amplifier stages when the output voltage violates the voltage limit, and to clamp the output voltage at an offset from the voltage limit.

Abstract: An electromechanical system (MEMS) accelerometer is described. The MEMS accelerometer may be configured to sense linear acceleration along one, two or three axes, and to sense angular acceleration about one, two or three axes. As such, the MEMS accelerometer may serve as 2-axis, 3-axis, 4-axis, 5-axis or 6-axis inertial accelerometer. In some embodiments, the MEMS accelerometer may comprise a single mass connected to at least one anchor via a plurality of tethers. In other embodiments, the MEMS accelerometer may comprise a proof mass connected to at least one anchor via a plurality of tethers and one or more shuttle masses connected to the proof mass via a second plurality of tethers. Rotational and linear motion of the MEMS accelerometer may be sensed using capacitive sensors.

Abstract: A MEMS resonant accelerometer is described. The MEMS resonant accelerometer may comprise a pair of proof masses configured to resonate when driven with periodic signals. In this respect, the accelerometer's proof masses may serve as masses for detecting accelerations as well as resonators. The MEMS resonant accelerometer may comprise drive electrodes for causing the proof masses to resonate and sense electrodes for sensing motion of the proof masses. The magnitude of a z-axis acceleration, that is, an acceleration perpendicular to the plane of the proof masses, may be detected by sensing the frequency at which the proof masses resonate in the presence of such an acceleration. The proof masses may be arranged to produce differential signals.

Abstract: A MEMS product includes a stress-isolated MEMS platform surrounded by a stress-relief gap and suspended from a substrate. The stress-relief gap provides a barrier against the transmission of mechanical stress from the substrate to the platform.

Abstract: A successive approximation register analog-to-digital converter (SAR ADC) typically includes circuitry for implementing bit trials that converts an analog input to a digital output bit by bit. The circuitry for bit trials are usually weighted (e.g., binary weighted), and these bit weights are not always ideal. Calibration algorithms can calibrate or correct for non-ideal bit weights and usually prefer these bit weights to be signal independent so that the bit weights can be measured and calibrated/corrected easily. Embodiments disclosed herein relate to a unique circuit design of an SAR ADC, where each bit capacitor or pair of bit capacitors (in a differential design) has a corresponding dedicated on-chip reference capacitor. The speed of the resulting ADC is fast due to the on-chip reference capacitors (offering fast reference settling times), while errors associated with non-ideal bit weights of the SAR ADC are signal independent (can be easily measured and corrected/calibrated).

Abstract: A microelectromechanical systems (MEMS) accelerometer is described. The MEMS accelerometer may comprise a proof mass configured to sense accelerations in a direction parallel the plane of the proof mass, and a plurality of compensation structures. The proof mass may be connected to one or more anchors through springs. The compensation structures may be coupled to the substrate of the MEMS accelerometer through a rigid connection to respective anchors. A compensation structure may comprise at least one compensation electrode forming one or more lateral compensation capacitors. The compensation capacitor(s) may be configured to sense displacement of the anchor to which the compensation structures is connected.

Abstract: In some exemplary embodiments, a MEMS accelerometer includes a device wafer having a proof mass and a plurality of tracking anchor points attached to a substrate. Each tracking anchor is configured to deflect in response to asymmetrical deformation in the substrate, and transfer mechanical forces generated in response to the deflection to tilt the proof mass in a direction of the deformation.

Abstract: A low capacitance n-channel analog switch circuit, a p-channel analog switch circuit, and a full CMOS transmission gate (T-gate) circuit are described. Resistive decoupling can be used to isolate the switch or T-gate from AC grounds, such as one or more switch control signal inputs or supply voltages. A semiconductor region that is separated from a body region of a pass field-effect transistor (FET) can be coupled to or driven to a voltage similar to the input voltage or other desired voltage to help reduce parasitic capacitance of the switch or T-gate. The switch or T-gate can have improved frequency bandwidth or frequency response. The switch can be useful in a programmable gain amplifier (PGA) or programmable gain instrumentation amplifier (PGIA) or other circuit in which excessive switch capacitance could degrade circuit performance.

Abstract: Apparatus and methods for transient overstress protection with false condition shutdown are provided herein. In certain configurations, a high-voltage tolerant actively-controlled protection circuit includes a transient overstress detection circuit, a clamp circuit electrically connected between a first node and a second node, a bias circuit that biases the clamp circuit, and a false condition shutdown circuit. The transient overstress detection circuit generates a detection signal indicating whether or not a transient overstress event is detected between the first and second nodes. Additionally, the false condition shutdown circuit generates a false condition shutdown signal based on low pass filtering a voltage difference between the first and second nodes, thereby determining independently whether or not power is present. The bias circuit controls operation of the clamp circuit in an on state or an off state based on the detection signal and the false condition shutdown signal.

Abstract: An apparatus includes an electrostatic discharge (ESD) protection device configured to protect a circuit from ESD conditions. The protection device includes an emitter region having a first diffusion polarity; a collector region laterally spaced apart from the emitter region, and having the first diffusion polarity; and a barrier region interposed laterally between the emitter region and the collector region while contacting the emitter region. The barrier region has a second diffusion polarity opposite from the first diffusion polarity. The device can further include a base region having the second diffusion polarity, and laterally surrounding and underlying the emitter region and the barrier region. The barrier region can have a higher dopant concentration than the base region, and block a lateral current flow between the collector and emitter regions, thus forming a vertical ESD device having enhanced ESD performance.

Abstract: A method of fabricating a super-capacitor provides a substrate, and then adds an electrode and electrolyte template film, having a well for receiving the electrode, to the substrate. The method also adds a second electrolyte to the electrode and electrolyte template.

Abstract: A connection device for connecting a load to a power supply, comprising at least first and second current control devices arranged in parallel between the power supply and the load, and a controller arranged to switch the current control devices on in sequence for temporally overlapping on periods.

Abstract: A delta-sigma modulator circuit comprising: an integrator circuit configured to produce an integrator output signal that represents an integration of an analog input signal, a comparator output signal and a periodic signal; a comparator circuit configured to produce the comparator output signal in response to a comparison of the integrator output signal with a first reference signal; and a periodic signal generation circuit configured to produce the periodic signal.

Abstract: Apparatus and methods for actively-controlled trigger and latch release thyristor are provided. In certain configurations, an actively-controlled protection circuit includes an overvoltage sense circuit, a thyristor or silicon controlled rectifier (SCR) that is electrically connected between a signal node and a discharge node, and an active trigger and latch release circuit. The overvoltage sense circuit controls a voltage of a dummy supply node based on a voltage of the signal node, and the active trigger and latch release circuit detects presence of a transient overstress event at the signal node based on the voltage of the dummy supply node. The active trigger and latch release circuit provides one or more trigger signals to the SCR to control the SCR's activation voltage, and the active trigger and latch release circuit activates or deactivates the one or more trigger signals based on whether or not the transient overstress event is detected.

Abstract: For broadband data communication, a data signal voltage at a signal input node can be converted to an output signal current at a signal output node. A first transistor device can contribute to the output signal current, with its transconductance or other gain reduced to accommodate larger signal swings, at which a second transistor can turn on and increase an effective resistance value of at least a portion of a gain degeneration resistor associated with the first transistor device. The second transistor can also contribute to the output signal current to help maintain or enhance an overall gain between the signal input node and the signal output node. Multiple secondary stages, push-pull arrangements, buffer amplifier configurations (which may or may not contribute to current in the gain degeneration resistor), input and output transformers, negative feedback to help reduce component variability, and frequency modification circuits or components are also described.