| 摘要 |
PURPOSE:To generate pulses of a random duty ratio by permitting a counter, having alternate initial values, to count from those initial values and by inputting a carry to a flip-flop every time its count value exceeds a maximum value. CONSTITUTION:Counter 21, when providing a four-bit count, can count up to maximum value M which is 15. To obtain a duty ratio of 5:3, a pulse signal is supplied to terminal T of flip-flop 23 at time intervals of 5:3. For this purpose, since a carry is generated every time counter 21 counts up over 15, the generation of the carry should be at time intervals of 5:3. Then, every time the output of flip-flop 23 is inverted in response to the initially set-up input of counter 21, 11 and 13 are alternately set in the counter, so that a signal of the 5:3 duty ratio can easily be obtained. |
