| 摘要 |
PURPOSE:To obtain a pulse width modulation circuit without malfunction, by outputting an output pulse until a counter is again preset, through the counting of a counter is stopped, when the counter preset with a digital value counts a maximum counting value. CONSTITUTION:After digital modulation signals d1-dn are stored in a preset circuit 4, they are preset in a binary counter 1. A clock (a) is applied to the counter 1 via a gate 5 and the counter 1 counts this clock (a). When the content of the binary counter 1 reaches a maximum count value, a detector 6 detects it, a detected output is applied to an output generator 7 and a gate 5 to close the gate 5. At every period corresponding to a period when the counter 1 reaches the maximum value from zero, the counter 1 is preset from the preset circuit 4. An output pulse width corresponding to the digital modulation signals d1-dn can be obtained from the output circuit 7. |
