| 摘要 |
PROBLEM TO BE SOLVED: To reduce the number of circuit parts for a printed wiring board without deteriorating the reliability of the reset release operation of the circuit when a power supply is turned on. SOLUTION: A power supply voltage which is matching the 2.5 V specification of an LCD controller 11 is generated by reducing input power supply voltage. Then, the reduced power supply voltage is inputted into a reset circuit 111 that is incorporated into the controller 11. When the power supply voltage reaches a prescribed level, the circuit 111 performs reset release of a DC/DC converter 13 and a reset release is conducted for the controller 11 with a prescribed time delay. Thus, the converter 13 and the controller 11 are reliably reset released in the order indicated above. Moreover, an external reset circuit and a reset circuit incorporated into the converter 13 are made unnecessary by effectively utilizing the circuit 111 incorporated into the controller 11.
|
