Comparator applications

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

Controller for switching regulator, switching regulator and light source

Abstract: A switching regulator (2-5) supplies a controllable stable average current to a load (1), such as series-connected light emitting diodes. A regulator controller (2) includes a hysteretic comparator (12, 30) which controls a switch in the form of a transistor (15) for switching current into an inductor (3). The comparator (12) has upper and lower thresholds defined by a hysteresis control (30). A first circuit comprising a fast current monitor (6) supplies a first signal representing the instantaneous current in the inductor (3). A second circuit (36, 37, 41, and 42) supplies a second signal representing an error between a desired regulator output and an actual regulator output. The second signal varies at least one of the upper and lower thresholds of the comparator (12, 30) with respect to the first signal.

Multi-level receiver circuit with digital output using a variable offset comparator

Abstract: A number of comparators are provided where each has a differential input coupled to receive a transmission line analog signal level. Each comparator has substantially variable offset that is controllable to represent a respective variable reference level, without requiring a separate input to receive a voltage reference level. An output of each comparator is to provide a value that represents a comparison between the transmission line analog signal level and the respective reference level.

Semiconductor active fuse operating at high supply voltage employing current oscillation

Abstract: A high-voltage semiconductor active fuse has first and second semiconductor elements, a comparator for comparing the voltages of the first and second semiconductor elements with each other, a driver for supplying a control voltage to the control electrodes of the first and second semiconductor elements according to the output of the comparator, a first diode connected between a first input terminal of the comparator and a low-potential power supply terminal of the comparator, and a second diode connected between a second input terminal of the comparator and the low-potential power supply terminal through a resistor. When detecting an abnormal current, the active fuse turns on and off the first semiconductor element to cause current oscillations, which blocks the conduction between an external input terminal and an external output terminal. The active fuse needs no shunt resistor and is capable of quickly responding to an abnormal current caused by an incomplete short circuit failure.

Method and apparatus for regulating power in a flyback converter

Abstract: An integrated circuit includes an operational amplifier configured to receive a current sense voltage (VCS) at a first input and an offset voltage at a second input. A comparator is coupled to the operational amplifier and adapted to receive at a first input an output voltage signal (VOUT) of the operational amplifier. A voltage limiting circuit is configured to receive a regulation voltage. A fold back correction circuit is coupled to the voltage limiting circuit and to a second input of the comparator. A pulse width modulator circuit is coupled to the comparator and is adapted to receive the output of comparator.

A 5.8nW, 45ppm/°C On-Chip CMOS Wake-up Timer Using a Constant Charge Subtraction Scheme.

Abstract: This work presents an ultra-low power oscillator designed for wake-up timers in compact wireless sensors. A constant charge subtraction scheme removes continuous comparator delay from the oscillation period, which is the source of temperature dependence in conventional RC relaxation oscillators. This relaxes comparator design constraints, enabling low power operation. In 0.18µm CMOS, the oscillator consumes 5.8nW at room temperature with temperature stability of 45ppm/°C (-10°C to 90°C) and 1%V line sensitivity.