| 摘要 |
PROBLEM TO BE SOLVED: To shorten a startup time of an IC by connecting a Zener diode to a resistor attached to an IC power supply of a DC-DC converter circuit using a switching IC. SOLUTION: In the DC-DC converter circuit, the startup resistor comprises a switching element and the switching IC, the timing and interval of switching is set by the switching IC, the on/off of the switching is determined by giving a command to the switching IC, a current is made to flow so that an input voltage is applied to a transformer primary side, energy is given to the input voltage by generating magnetic flux at a transformer core, the input voltage is converted to a voltage value of a transformer secondary-side output, and a stipulated voltage is outputted. In the DC-DC converter circuit, the Zener diode is inserted between the resistor and GND in a circuit wherein the resistor is inserted between a VCC voltage and the GND for preventing the refloating of the VCC voltage, when the VCC voltage, fed to the switching IC is refloated in power-in and power-off. COPYRIGHT: (C)2004,JPO
|
