| 摘要 |
<p>PURPOSE:To always obtain a PWM signal having the prescribed pulse width regardless of the temperature change by using a comparator which compares the output of a level shift circuit with the output of an absolute value circuit to obtain the pulse width modulation output. CONSTITUTION:The voltage obtained at the lower edge of a triangular wave is fixed at a prescribed level of a level shift circuit 12 which is formed by a diode circuit. For the reference voltage of an absolute value circuit 4, the input signal is switched between the positive and negative states by the reference voltage V0 decided by a diode. Thus the difference of both voltage levels can be set at a prescribed level with substantially no control. Then the forward drop voltage change if caused by the temperature characteristics of the diode can be offset since the diodes are used to both a voltage generating circuit 11 and the circuit 12. As a result, the same PWM pulse signals can be obtained regardless of the temperature change.</p> |
