| 摘要 |
PROBLEM TO BE SOLVED: To provide a switching regulator having simple circuitry, and capable of generating a constant current easily.SOLUTION: Switching elements SW1, SW2 operate at predetermined switching frequency and duty ratio, and generate a primary voltage V1 from an input voltage Vi. An immittance converter M1 has a resonance frequency equal to the switching frequency, and an impedance viewed from one pair of terminals proportional to the admittance of a circuit or an element connected with the other pair of terminals, and generates a secondary current I2 having a secondary voltage V2 from a pair of output terminals when a primary voltage V1 is applied to a pair of input terminals. The secondary current I2 flows through a resistor Ro, and an output voltage Vo lower than the secondary voltage V2 is generated. A control circuit 10 matches the output current of the switching regulator to a desired current value Iset, by changing the input voltage Vi so that the primary voltage V1 is equal to the sum of the product of the desired current value Iset and the resistance Ro, and the output voltage Vo. |
