| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a current mode control DC-DC converter having a high-accuracy current restriction function with a simple circuit configuration, and to provide a control circuit for the same. <P>SOLUTION: A current mode control DC-DC converter controls ON and OFF of a main switch Q to control an energy stored in an inductor L from an input direct current voltage Vin, and supplies a direct current output voltage Vout to a load 2. A current mode PWM control circuit 10 detects a current flowing in the inductor L from both-end voltages Vcs+ and Vcs- inputted from a current detection resistance Rcs, and generates a reset signal (an off trigger signal OFFtrig) to an RS latch circuit 5. At that time, a level shift circuit 11 outputs a reference voltage signal Va obtained by shifting the level of the voltage Vcs- by a voltage V2 depending on an output voltage Vea from an error amplifier 9, to a comparator 8. The comparator 8 supplies the off trigger signal OFFtrig generated by comparing the reference voltage signal Va with the voltage signal Vcs+ to the RS latch circuit 5. <P>COPYRIGHT: (C)2012,JPO&INPIT |
