VCO and VCXO design

hi!

can anyone help me with my design exercise?

i am tasked to design:

1. A vco centered at 10 MHz (any implementation is allowed but simplest is most preferred). It will use varactor diode as the voltage dependent element. Acceptable output voltage range is 1Vpp-5Vpp.

2. A 500 Hz reference crystal oscillator that will serve as a reference for a future PLL.

i'm currently looking for related and helpful tutorials and previous projects and schematics.

any help will be greatly appreciated! :)

thanks in advance!

yiyen

Make a ring oscillator with odd number of inverters. Use varactor in RC circuit to control the frequency

dear use lm566

we're not allowed to use LM566..how i wish we can use it, it would really be much easier.. we need to implement it in transistor or opamp level..not in IC.. thanks. :D

learning