DC/DC Converter is the core and the key of a low-voltage, high-current, high -efficiency power supply. It is divided into two major categories of switch mode and linear. Earlier linear step-down converter is large, heavy, inefficient. And it's power factor is little. So it's easily impacted by power frequency and power voltage fluctuation. As the result, switch-mode converter replaced most of the linear converter by the features of small, light, efficient, output forms is various, output voltage range is broad.
The DC-DC conversion module designed in this paper is switch mode, it is formed by a step-down module and a step-up module. Converter chip is MC34063, dedicated to DC-DC converter control part. To achieve a wide range of input DC voltage converted into two respectively. One of the output fixed 5V, another is continuously adjustable between 3-12V. Output voltage Through the computing circuits conversion into 0-5V, carried out by the ADC0804 analog-to-digital conversion, and after treatment by single-chip, with digital display. The voltage conversion range of the transformation module Meet the design requirements after tested and showed, the abs olute value of its output voltage error was less than 1.9%.
Key Word: DC-DC MC34063 A/D conversion LED display
