Comparator applications

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

DC-to-DC converter having enhanced control features and associated methods

Abstract: A DC-to-DC converter includes a comparator for controlling a high-side switch and has one input connected to a switch signal and another input connected to a peak current reference signal. A comparator bias boost circuit increases a bias to the comparator to provide accurate comparisons even when the switch signal and the peak current reference signal are both relatively close to a voltage of the source. The additional bias may be provided by a voltage which is typically available for a DC-to-DC converter. More particularly, the high-side switch has a terminal defining a phase node, and the additional bias voltage may be provided by a capacitor referenced to the phase node to provide the bias higher than a voltage of the source and responsive to switching at the phase node. The converter preferably further includes one or more clamps for clamping the output of the comparator during a relatively rapid change in the bias. A clock may be used for turning on the high-side switch. The comparator may include an additional input, and the clamps may further deliver a blanking signal based upon the clock to the additional input of the comparator so that at least one of the comparator output and inputs is clamped responsive to the blanking signal. Method aspects of the invention are also disclosed.

Monitor for current circuit of appliance, e.g. separate lamps of motor vehicle - uses differential amplifier as comparator with inputs across fuse and output supplying warning appts. if heat exceeds threshold value

Abstract: A load circuit monitoring arrangement contains a measurement resistance in the leads to at least one load (1). The resistance input is connected to one comparator (4) input via a potential divider (3) and its output is connected to the other comparator input. The comparator drives a warning device. The fuse (2) in the lead to the load can be used as the measurement resistance. For functional monitoring of the load the threshold of the comparator is matched to the load current and the variation in the resistance of the fuse with temp. ADVANTAGE - Contains min. number of components and occupies relatively little space. Measurement resistance does not introduce any additional potential drop in load circuit or generate additional heat loss.

A single-inductor 8-channel output DC-DC boost converter with time-limited one-shot current control and single shared hysteresis comparator

Abstract: This paper describes a time-limited one-shot current control technique used to extend the outputs of a single-inductor multiple-output DC-DC converter without stability and complexity issues The proposed scheme also reliably supports many outputs with unbalanced loads True all-comparator control is realized with a single shared hysteresis comparator and a fixed switching frequency of 800-kHz The maximum efficiency reaches 92% The fabricated 8-channel output chip occupies 24×21 mm2 in a 035-µm CMOS process

P‐51: a‐IGZO TFT Based Operational Amplifier and Comparator Circuits for the Adaptive DC‐DC Converter

Abstract: In this paper, we present an operational amplifier (op-amp) based on amorphous Indium-Gallium-Zinc-Oxide thin-film transistors (a-InGaZnO TFTs) to achieve a comparator operated by pulse-width-modulation (PWM) control-loop structure, which can be used for dc-dc converter circuits integrated in the display driving system. Based on electrical characteristics of the fabricated a-InGaZnO TFT, we proposed a novel NMOS op-amp to achieve the overall gain of 19.2dB. On the basis of the proposed op-amp, we fabricated a-InGaZnO TFT comparator circuit, which could successfully operate at 100 Hz to control the duty ratio from 25% to 75% with the slew rate of 0.625V/μs.

D/A conversion apparatus with offset compensation function and offset compensation method for a D/A conversion apparatus

Abstract: It is an object of the present invention to enable a DC offset of a D/A converter to be removed substantially completely even when a DC offset exists in a comparator. An input switchover switch 160 is provided between complementary outputs A+, A− of a D/A converter 130 and an input of a comparator 150 . An input signal correction section 110 calculates a zero-cross delay value when an output A+ of the D/A converter 130 and a + input of the comparator 150 are connected and an output A− of the D/A converter 130 and a − input of the comparator 150 are connected, and a zero-cross delay value when the output A+ of the D/A converter 130 and the − input of the comparator 150 are connected and the output A− of the D/A converter 130 and the + input of the comparator 150 are connected, adds up the two zero-cross delay values calculated, decides whether the value is positive, negative or zero, integrates the result and uses a DC offset compensation value generated to thereby correct a digital input signal using an adder 128.