258 results about "Log amplifier" patented technology

An electrosurgical system for performing an electrosurgical procedure is provided and includes an electrosurgical generator and a calibration computer system. The electrosurgical generator includes one or more processors and a measurement module including one or more log amps that are in operative communication with the processor. The calibration computer system configured to couple to a measurement device and is configured to measure parameters of an output signal generated by the electrosurgical generator. The calibration computer system is configured to compile the measured parameters into one or more data look-up tables and couple to the electrosurgical generator for transferring the data look-up table(s) to memory of the electrosurgical generator. The microprocessor is configured to receive an output from the log amp(s) and access the data look-up table(s) from memory to execute one or more control algorithms for controlling an output of the electrosurgical generator.

An amplifying circuit of a display device including a plurality of pixels includes an input unit, a bias unit, and an output unit. The input unit is coupled between a first power source for supplying a first voltage and a second power source for supplying a second voltage, receives a first input signal and a second input signal, and is controlled by the first and second input signals. The bias unit receives a bias voltage for operating the input unit, and includes a first node and a second node controllable by the input unit. The output unit applies an output voltage to a pixel by using a first output transistor turned on / off by a signal applied to the first node and a second output transistor turned on / off by a signal applied to the second node, and the first output transistor is a different type to the second output transistor. In this instance, the input unit includes a first input transistor having a first terminal coupled to a first power source and being turned on / off by a first input signal and a second input transistor of the same type as the first input transistor, having a first terminal coupled to the first power source, and being turned on / off by a second input signal. The bias unit includes a first transistor controllable by the on / off state of the first input transistor and a second transistor controllable by the on / off state of the second input transistor.

The disclosure concerns a tunable logarithmic detector amplifier (TLDA) system where dynamic tuning functionality is applied to resonant circuits used for feedback control as well as applying tuning to the amplifier. Control signals for the tuning function are generated from the baseband processor. The control of the amplifier tuning and resonator tuning can be performed from information derived from baseband where metrics such as SNR, SINR or CQI are used to optimize system performance. Bandwidth and sensitivity of the receiver are key specifications targeted for optimization using this technique. This technique can be implemented in designs where a wide bandwidth is required.

A successive approximation A / D converter includes a sample-hold amplifier circuit configured to sample and hold an input analog voltage to produce an internal analog voltage proportional to the input analog voltage with a voltage gain being smaller than 1, a switched capacitor D / A converter coupled to the sample-hold amplifier circuit and including a plurality of capacitors for storing electric charge responsive to the internal analog voltage, the switched capacitor D / A converter configured to switch couplings of the capacitors in response to a control signal to produce a comparison analog voltage responsive to the internal analog voltage and the control signal, a comparator coupled to the switched capacitor D / A converter to produce a comparison result signal responsive to the comparison analog voltage, and a control circuit coupled to the comparator to supply the control signal responsive to the comparison result signal to the switched capacitor D / A converter.

A gradient amplifier arrangement is described that comprises a gradient amplifier power stage. The device may be employed to provide a current to a gradient coil, as in a MRI system. The circuitry disclosed includes a series coupling of a first bridge amplifier operating at a first voltage, a second bridge amplifier operating at a second voltage, a third bridge amplifier operating at a third voltage, and a gradient amplifier control stage. The amplifiers may provide output voltages at different levels, and may be switched at different times and frequencies to provide a range of output voltage and current levels.

A voltage regulator includes first and second closed-loop amplifiers and a N-type transistor. The first amplifier receives a first reference voltage and a feedback voltage. The second amplifier is responsive to the first amplifier and to the regulated output voltage of the regulator. Both amplifiers are biased by a biasing voltage. The second amplifier has a bandwidth greater than the bandwidth of the first amplifier and a gain smaller that the gain of the first amplifier. The N-type transistor has a first terminal responsive to the output of the second amplifier, a second terminal that receives the input voltage being regulated, and a third terminal that supplies the regulated output voltage. The feedback voltage is generating by dividing the regulated output voltage. An optional fixed or dynamically biased current source biases the first terminal of the N-type transistor. The voltage regulator optionally includes an overshoot correction circuit.

The levels of the power supply and the ground are kept constant against a parasitic resistance by keeping the constant current of an amplifier irrespective of the size of a pixel signal and the gain of the amplifier in this case in an image signal reading circuit system having the amplifier arranged to each column. The amplifier has a limiter at an output terminal thereof which limits an output voltage of the amplifier to a range for keeping the constant consumption-current.

Transconductance-based variable gain amplifiers amplify an input voltage by converting the voltage difference to a current and then amplifying the result. At least one resistor network is adjusted depending on the magnitude of the input voltage difference and the output desired. A network of MOS transistor switches with a small footprint adjusts the resistance of the input voltage circuit in a way to insure consistent resistance and low stray capacitance.