Abstract: A comparator includes a current mirror module, a comparison module and a buffering and outputting module. The current mirror module provides a bias current to the comparison module. The comparison module comprises a positive input end, a first negative input end and a second negative input end, the positive input end connects to an external terminal, the first negative input end and the second negative input end input a low threshold voltage and a high threshold voltage, respectively. The comparison module compares a voltage of the positive input end to the low threshold voltage and the high threshold voltage, and outputs a comparison result to the buffering and outputting module.

Abstract: The present invention discloses a class D amplifier chip with duty ratio limiting functions and the device thereof, a class D amplifier chip includes triangle wave modules, PWM modulation modules, duty ratio detection modules and logic control modules, the input differential audio signals and triangle wave signals generated by the triangle wave module are converted into low voltage pulsed PWM signals through the PWM modulation module, then gets driving processed and generates high voltage pulses; the duty ratio detection module real-time detects the duty ratio of PWM signals, when the logic control module decides the duty ratio of the PWM signals is larger than the preset maximum value, the PWM module is controlled to stop working, equals to close the audio output of the class D amplifier device; which limits the amplitude of the output audio signals, avoids burning the speaker due to an overlarge amplitude.

Abstract: The present disclosure discloses a power converter and a switching power supply device. The power converter includes an energy storing and outputting circuit used for charging a load after storing energy, a main switch used for transmitting input power to the energy storing and outputting circuit when the main switch is conducting, an after flow switch used for supplying an after flow loop to the energy storing and outputting circuit when the main switch is shut down, a driving circuit used for changing connecting states of the main switch and the after flow switch according to a preset clock frequency, and a testing circuit and a feedback circuit, the testing circuit is used for testing a voltage on a connecting node of the main switch and the after flow switch.

Abstract: The present invention discloses a comparator and low power consumption oscillator thereof.

Abstract: The present disclosure discloses a power converter and a switching power supply device. The power converter includes an energy storing and outputting circuit used for charging a load after storing energy, a main switch used for transmitting input power to the energy storing and outputting circuit when the main switch is conducting, an after flow switch used for supplying an after flow loop to the energy storing and outputting circuit when the main switch is shut down, a driving circuit used for changing connecting states of the main switch and the after flow switch according to a preset clock frequency, and a testing circuit and a feedback circuit, the testing circuit is used for testing a voltage on a connecting node of the main switch and the after flow switch.

Abstract: The present invention discloses a class D amplifier chip with duty ratio limiting functions and the device thereof, a class D amplifier chip includes triangle wave modules, PWM modulation modules, duty ratio detection modules and logic control modules, the input differential audio signals and triangle wave signals generated by the triangle wave module are converted into low voltage pulsed PWM signals through the PWM modulation module, then gets driving processed and generates high voltage pulses; the duty ratio detection module real-time detects the duty ratio of PWM signals, when the logic control module decides the duty ratio of the PWM signals is larger than the preset maximum value, the PWM module is controlled to stop working, equals to close the audio output of the class D amplifier device; which limits the amplitude of the output audio signals, avoids burning the speaker due to an overlarge amplitude.