| 摘要 |
PURPOSE:To obtain the titled oscillator with small circuit scale and high phase accuracy by taking an output of a counter circuit as a high-order bit and outputting the output of an adder circuit as a low-order bit. CONSTITUTION:A control signal inputted from an input terminal 10 is added to a value corresponding to the center frequency inputted from an input terminal 11 by an adder circuit 12 and the result is inputted to an adder circuit 13. An output of the adder circuit 13 is delayed by T at a register circuit 14 and the result is fed back to the other input of the adder circuit 13. As a result, the adder circuit 13 stores the inputted data one after another. An m-bit counter 15 is counted once every time the adder circuit 13 overflows. The overflow is detected by the change of the most significant bit of the adder circuit 13 from '1' to '0'. Thus, the same phase accuracy of a digital oscillator using an (m+n)-bit adder circuit is provided, n-bit is enough for the adder circuit and the oscillator with small scale is obtained.
|
