| 摘要 |
PURPOSE:To prevent any temperature dependancy from appearing as a whole when it is used for an oscillator or other circuit by providing the temperature characteristic to the hysteresis of a comparator. CONSTITUTION:A transistor (TR)14 switches a current value of a terminal t2 of a current mirror circuit 11 to 0 or 2I and TR15 generates a collector current in response to a terminal voltage of a capacitor 13. On the other hand, a TR18 for a comparator switch compares a collector current of the TR15 with the sum of output currents of current mirror circuits 16, 17 and switches the current value of the current mirror circuits to 0 or nI. Then a capacitor repeats charge/discharge for oscillation. The hysteresis Ehy depends on a VT and is independently of a current I. That is, the hysteresis has a temperature characteristic. Thus, no temperature dependancy appears in the oscillation period. Further, the same effect is obtained by using the comparator for other circuits such as an oscillator. |
