| 摘要 |
PROBLEM TO BE SOLVED: To provide a power source at a low cost which performs excellent boosted starting characteristics, by utilizing booster capacity of a booster circuit to a maximum limit. SOLUTION: A power source unit 1 comprises an analog switch 17 for switching a booster circuit 13 and a high-voltage load circuit 19 to a connecting state or an interrupting state between an output stage of the circuit 13 and the circuit 19, and a latched circuit 16 for opening a contact of the switch 17 when power source ON is detected by a power source ON detector 14 to switch the circuit 13 to the circuit 19. And, the circuit 16 closes the contact of the switch 17 when counting of a predetermined time is finished by a timer circuit 15 to connect the circuit 19 to the circuit 13. Accordingly, the circuit 13 can boost a power source voltage VDD to a driving voltage VLCD having a predetermined voltage level in the state that it is disconnected from the circuit 19. |
