| 摘要 |
<p>PURPOSE:To set optionally the temperature characteristic of the oscillated frequency by using a current conversion circuit so as to output a current having a temperature characteristic to cancel the change in the charge/discharge time attended with the temperature characteristic of the capacitor. CONSTITUTION:A voltage VA across a resistor 5 is produced by an output constant current I0 of a constant current circuit 1 and the resistor 5. A collector current is subject to mirror processing by a current mirror circuit comprising resistors 9, 10 and transistors 8, 11 and becomes an output current I1 of a current conversion circuit 13. The current I1 is given to an oscillation circuit 2 connecting to a capacitor 3, the circuit 2 leads the current I1 to the capacitor 3, which is charged and discharged between setting voltages VH and VL to oscillate the circuit 2. A resistor 7 acts like outputting the current I1 having a temperature characteristic to cancel the change in the charge/discharge time attended with the temperature characteristic of the capacitor 3. Thus, the temperature characteristic of the oscillated frequency is set optionally by selecting the resistors 5, 7.</p> |
