A prescaler, based on the MC12080 is presented here. The MC12080 is a single modulus divide by 10, 20, 40, 80 prescaler for low power frequency division of a 1.1GHz signal. However, it can be used for frequencies up to 1.5GHz. This circuit has been designed for the front end of a frequency counter.
The MC12080 is set for 1:40 prescale. The divide ratio can be set in another value from the control inputs SW1, SW2 and SW3. The MC12080 produces an output signal of about 1200mVp-p when driven from a high frequency signal source in the range of 70MHz to 1.6GHz. Observing the schematic, you will notice that we also use a MAX9203 high speed comparator in order to match the output signal to TTL levels. R4 is used for trigger level adjust.
If you decide to build this circuit, remember to use SMD only.
Author: A.G
