| 摘要 |
PROBLEM TO BE SOLVED: To obtain a current mode control type switching regulator which can operate stably, being able to generate a slope voltage Vslp excellent in linearity. SOLUTION: A slope voltage generating circuit 4 includes: an inductance current detecting circuit 11, which detects an inductance current iL when a switching transistor M1 is ON and converts it into a voltage; and a lamp voltage generating circuit 12, which generates a lamp voltage. In the lamp voltage generating circuit 12, a constant current circuit 24, a resistor R25 for offset voltage generation, and a lamp capacitor C21 for generating the lamp voltage are connected in series between an input voltage Vin and a ground voltage GND, and it adds up: a voltage Vd, where a voltage drop of the resistor R25 when a constant current i24 is supplied from the constant current circuit 24 to the resistor R25 and the lamp capacitor C21 and a voltage Vb charged in the lamp capacitor C21 are added up; and the output voltage of an inductance current detecting circuit 11, thereby making a slope voltage Vslp. COPYRIGHT: (C)2009,JPO&INPIT
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