| 摘要 |
PURPOSE:To stably control an output of a switching regulator, by a magnitude comparator decreasing the voltage of a ciricuit, when the input voltage of a DELTAM encoder gradually increases and a counting value of an accumulator reaches a specified value. CONSTITUTION:Since an input voltage of a DELTAM encoder 305 is gradually increased at the application of power supply, a pulse with consecutive ''1s'' is obtained at an output of the encoder 305. This DELTAM signal is applied to an input terminal of an accumulator 309 via an LED 306 and a phototransistor TR 307 and ''1'' is added to the accumulator 309. If the value of the accumulator 309 exceeds a value set to a register 310, a magnitude comparator 311 turns off a TR 105 and a voltage across a capacitor 108 is reduced by this operation. Thus, the register 105 repeats intermission according to the output of the accumulator 309 to set an output voltage of the switching regulator to the register 310. |
