Comparator applications

About: Comparator applications is a research topic. Over the lifetime, 2518 publications have been published within this topic receiving 26639 citations.

Pll frequency synthesizer and method for controlling the pll frequency synthesizer

Abstract: A PLL frequency synthesizer which is provided with a voltage detector (9) which detects the present value of a control voltage applied to a voltage-controlled oscillator (6), a storage device (7) which stores in advance the set values of a plurality of control voltages corresponding to the set values of a plurality of frequency dividing numbers set in a frequency divider (2) and outputs the set value of the control voltage corresponding to the frequency dividing number set in the frequency divider by selecting the set value out of the set values of the control voltages, a voltage value comparator (8) which compares the present value of the control voltage detected by the detector (9) with the set value of the control voltage outputted from the device (7), and a switching circuit (10) which outputs either the phase difference signal generated by means of a phase comparator (3) and representing the phase difference between the phase of a frequency dividing signal outputted from the divider (2) and that of a reference frequency signal or the output signal of the comparator (8) by switching. The comparator (8) controls the circuit (10) so that a charge pump (4) can be driven with its own output signal when the difference between the present value of the detected control voltage and the set value of the control voltage from the device (7) is larger than a prescribed value or with the phase different signal from the phase comparator (3) when the difference is not larger than the prescribed value.

Automatic regulation of power delivered by ultrasonic transducer

Abstract: An ultrasonic generator has an output circuit for delivering ultrasonic power to a load through a transducer, the generator having an amplitude control input coupled to the output of a comparator, the inputs of which are coupled to a user interface circuit. The output circuit produces voltage and current signals which are applied to a multiplier in the interface circuit, which produces a power signal applied to an error input of the comparator, the interface circuit also having a signal processor which receives a user-input reference and applies it to a reference input of the comparator. The output of the comparator regulates the power output of the generator to the reference level, and is also coupled to an indicator circuit for providing an visual indication of whether or not the apparatus is in regulation.

Analog/digital converter apparatus

Abstract: An analog/digital converter apparatus includes a reference signal generator circuit for generating a reference signal, a comparator section for determining a relationship in level between an input analog signal and the reference signal, and an encoder for converting a comparison result of the comparator section into a digital signal as an output signal. The comparator section has a comparator for comparing the input analog signal with the reference signal and a switching circuit which is interposed between the comparator and each of an input terminal for the input analog signal and a reference signal output terminal for the reference signal and used for switching the input signal lines of the comparator to compensate an equivalent input offset.

Fully differential interpolating comparator bank and method

Abstract: An interpolating comparator bank having first and second differential amplifiers, each having a differential input and a differential output and first, second and third comparator circuits, each having differential inputs. The differential output of the first differential amplifier and second differential amplifier are coupled to the first and second comparator inputs, respectively. The differential outputs of the first and second differential amplifiers are also both coupled to the differential input of the second comparator circuit. In analog to digital converter circuit applications, the first and second comparators function to provide outputs indicative of the magnitude of a differential input voltage relative to first and third differential reference voltages produced, for example, by a resistor network. The second comparator circuit provides an output indicative of the magnitude of the differential input relative to a second differential input voltage which is not produced by the resistor network but which has a magnitude intermediate that of the first and second differential reference voltages.

Apparatus for use in testing an internal combustion engine ignition system

Abstract: An apparatus for testing an i.c.e. ignition system of the kind including an ignition coil and a semi-conductor switch means controlling current interruption in the coil primary, includes a voltage comparator connected to compare the voltage across the switch means with a predetermined voltage. The comparator output starts a monostable timer circuit, the output of which is gated with the output of the comparator to produce an output signal only if the voltage across the switch means falls below the predetermined voltage within a predetermined time duration.