| 摘要 |
<p>PURPOSE:To remove an unstable period at the time of turning on a power supply and to obtain a stable operation state by switching power supply to an IC connected with an oscillation circuit to a main power supply synchronously with the start of oscillating operation. CONSTITUTION:When a main switch 1 is turned on, the output voltage Vcc of the main power supply 3 is boosted, and when the oscillation circuit 8 reaches an oscillatable voltage Voc, the output of a voltage detecting circuit 10 is turned from an 'L' level to an 'H' level. Consequently, transistors(TR) 5, 6 are successively turned on and the output voltage Vcc of the main power supply 3 is inputted to a power supply voltage input terminal 1V of the IC4. Since the inverse of STBY terminal is switched from an 'L' level to an 'H' level simultaneously with said input, the oscillation circuit 8 starts oscillation. Since the power supply to the IC is switched to the main power supply 3 simultaneously with the operation start of the circuit 8, a sufficient voltage can be secured and data stored in a RAM4B built in the IC4 can be stored.</p> |
