Analog Devices Global

Analog Devices International Unlimited Company

Sharad Vijaykumar

Jun Gao

Patrick C Kirby

Gerard Mora-Puchalt

Avinash Gutta

Tony Yincai Liu

Michal Brychta

Alan Patrick Cahill

A line protector circuit comprises an external side switch circuit coupled to an external circuit node of the line protector circuit, an internal side switch circuit coupled in series to the external side switch circuit and an internal circuit node of the line protector circuit, a high supply circuit node and a low supply circuit node, and switch control circuitry configured to deactivate the internal side switch circuit and divert a bias current from the external side switch to the low supply circuit node when the external voltage exceeds a high supply voltage of the high supply circuit node.

Bootstrapped line-protector CMOS switch

The present disclosure provides a current-to-voltage signal converter which may operate at an adjusted voltage. The current-to-voltage converter includes a trans-impedance amplifier which converts a current input into a voltage output. The voltage output may operate around an undesirable predetermined voltage, and must therefore be adjusted in order to make it suitable for any downstream signal processing circuitry, such as an ADC. As such, a subtractor circuit is coupled to the output of the trans-impedance amplifier. At the input of the subtractor circuit, a voltage adjustment circuit is employed, to adjust the voltage input to the subtractor circuit. As such, the input to the subtractor is adjusted between a first predetermined voltage threshold and a second predetermined voltage threshold, and the subtractor circuit may therefore be a low-voltage component.

Current-to-voltage signal converter

Techniques are provided for an integrated circuit, current loop interface that can receive and extract a high-frequency digital communication signal from a low-frequency analog current signal using a complex impedance circuit. The complex impedance circuit can allow for low input impedance at the lower frequencies of the analog current signal and high input impedance at the higher frequencies of the digital communication signal.

Communication receiver interface for current loop circuit

The amplifier circuit includes a pair of differential input stages coupled to an output stage where both a selected input stage and an unselected input stage are active with one of either a differential input signal or a reference voltage. A switching network couples a first input differential signal to a first differential input stage and a reference voltage to a second differential input stage when an amplifier input signal is less than a threshold voltage. The switching circuit also couples the second input differential signal to the second differential input stage and the reference voltage to the first differential input stage when the amplifier input signal is greater than the threshold signal.

Operational amplifier

A delta-Vbased bandgap reference voltage circuit generates a temperature stable reference voltage. First and second paths of the circuit each include a respective transistor coupled in series with a resistance. The collector current density of the transistor in first path is lower than the collector current density of transistor in the other path. A control path is used to generate a 2Vvoltage that is coupled to the base nodes of the resistors in each path. A resistance that is coupled between a common node of a first end of the two paths and a circuit ground node. The circuit current is controlled by this resistance and a voltage drop of 2&#x394;Vis across the resistance. The output reference voltage of the circuit is 2(V+&#x394;V) when stack resistors in each path are used.

Temperature compensated reference voltage circuit

A compensation capacitor can be added to an amplifier for stability. Disclosed are systems and methods for improving the power supply rejection ratio (PSRR) performance of an amplifier in the presence of one or more compensation capacitors.

Apparatus and method for improving power supply rejection ratio

An embodiment of a digital-to-analog converter circuit includes a resistor network connected to an output node, a switch network having a first plurality of switches connecting the resistor network to a first circuit node and a second plurality of switches connecting the resistor network to a second circuit node, a voltage reference to supply a reference voltage to the first circuit node, and a current generator connected to the first circuit node and the second circuit node, to generate a compensation current, draw the compensation current from the first circuit node, and supply the compensation current to the second circuit node. The current generator can generate the compensation current as a function of a current or a voltage of a component of the voltage reference or as a function of an analog output voltage produced at the output node.

Growing community of inventors

Bengaluru, India

Sharad Vijaykumar