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RC6564
PRODUCT SPECIFICATION
4
P
VCO Internal Schematic
VCC2
VCC_HF
VCC_RF
VCC_XTL
VCO_Fs
VCO_In
VDDD1
VDDD2
VDDA
VRT
XTL_Out
XTL_Tnk
34
39
4
43
6
5
30
27
10
33
2
1
Analog Supply Voltage (12V)
Analog Supply Voltage (12V)
Supply Voltage (5V) for High Frequency Mixed Signal Sections
Supply voltage for Crystal Oscillator
VCO External Frequency Select Circuit Connection
VCO Input. Can be used for directly feeding external LO.
+5V Digital supply
+5V Digital supply
+5V power supply voltage
Output reference voltage for top of A/D input range
Crystal Oscillator Output
Crystal Oscillator Frequency Select Circuit Connection
Pin Descriptions
(continued)
Pin Name
Pin Number
Pin Function Description
V
CC
–R
F
(4)
VCO–F
S
(4)
TO MIXER
+
–
VCO–IN (5)
Q5
Q3
GND-VCO
47.7
I
C
=0.9mA
Q1
Q4
The VCO is designed as a Colpitts oscillator. The frequency
is controlled by the external resonance circuit. The oscillating
transistor is Q1 in common base configuration. In case it is
necessary to inject the signal in place of LO in the mixer pin
VCO_Fs is recommended to be open and the injected signal
on pin VCO_In to be under 100mVpp.