User's Manual

y Audio amplifier connection from D_S UB pin 1
y F requency S ynthesiser
y Transmitter
y Automatic Power C ontrol
Audio frequency connections
Processed data from the U601A is applied to the V C O via V R 521
F requency synthesiser circuit
With data received from the E E PR OM (U911) the frequency synthesiser circuit controls and
Produces the R F carrier frequency for the transmitter durin g transmit and the local oscillator
frequency for the receiver.The frequency synthesiser circuit is comprised of:
y 12.8MHZ V C TC X O
y V oltage C ontrolled Oscillator (V C O)
y C harge Pump and Loop F ilter
y PL L F requency S ynthesiser
y Dual Modulus Prescaler
PLL S ynthesiser
The PL L synthesiser circuit is common to both the transmitter and receiver,
The synthesiser comprises:
TC X O