Composition of charger
Nov 19, 2019| Shenzhen Shenchuang Hi-tech Electronics Co., Ltd(SChitec) is a high tech enterprise which specialized in phone accessories production and sales. Our main products include travel chargers, car chargers, USB cables, power banks and other digital products.All products are safe and reliable, with unique styles.products pass certificates like CE,FCC,ROHS,UL,PSE,C-Tick,etc, If you are interested in, you can contact ceo@schitec.com directly.
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Composition of charger
The charger uses the power semiconductor device as the switching element, which can control the duty cycle of the switching element to stabilize the output voltage. The charger is mainly composed of DC / DC converter, driver, signal source and comparator amplifier.
The functions of each link are as follows:
(1) DC / DC converter: used for power conversion, it is the core part of charger. DC / DC converter has many kinds of circuit forms, among which PWM converter with square wave control waveform and resonant converter with quasi sine wave operation waveform are widely used.
(2) driver: the amplifying part of the switch signal, amplifying and shaping the switch signal from the signal source to meet the driving requirements of the switch tube.
(3) signal source: generate control signal, which is generated by other excitation or self excitation circuit. It can be PWM signal, PFM signal or other signals.
(4) compare amplifier: compare the given signal and output feedback signal, control the amplitude, frequency and waveform of the switch signal, and control the duty cycle of the switch device through the driver to achieve the purpose of stable output voltage.
In addition, the charger also has auxiliary circuits, including start circuit, over-current voltage protection circuit, input filter circuit, output sampling circuit, function indication circuit, etc.
Compared with the linear power supply, the transient transformation of the input is more reflected in the output. When the switching frequency is increased, the frequency characteristic of the feedback amplifier is improved, so that the transient response index of the charger is also improved. The transient response of the load conversion is mainly determined by the characteristics of the output LC filter, so the transient response can be improved by increasing the switching frequency and reducing the LC value of the output filter.