【摘要】 介绍了一种可用作FSK调制器的数字可编程振荡器(DPO)的设计。该振荡器使用一片PLL电路LM565,其VCO的中心振荡频率由8031单片机经由CMOSCD4066开关所接的电阻阵列来控制。在88KHz-678KHz数字可变的频率范围内获得了良好的方波和三角波。将电路改动为一个正弦的DPO后,得到了一个由8031控制的相位连续的BFSK调制输出。更多还原

【Abstract】 The design of a Digitally Programmable Oscillator (DPO) is described for applications in the area of FSK modulator. DPO is designed using a PLL chip LM565, the centre frequency of VCO within which is controlled by 8031 microcontroller using a Resistor Array implemented by CMOS CD4066 switches. Good quality square and triangular waves are obtained from the block whose frequencies in the range of 88KHz to 678KHz are varied digitally. DPO will be a sinusoidal DPO by improving the circuit. A good quality FSK output are easily obtained with good phase continuity which is controlled by using 8031 microcotroller.更多还原