Tait TB9100 - Page 31

TB9100 Reciter Service Manual Reference Switch 31
© Tait Electronics Limited January 2006
Figure 4.1 Reciter External Reference Block Diagram
/R
/N
10 or 12.8MHz
External Reference
Internal Reference
12.8MHz TCXO
Programmable
Reference Divider
Programmable
VCO Divider
Phase
Detector
Charge
Pump
f
ref
f
VCOfb
Software
Register
External Reference
Detector
Lock
Detect
RISC
8/9
Prescaler
Frequency Synthesizer IC
Loop
Filter
External Reference
12.8MHz VCO
Clock
Data
Chip Select/Latch Enable
Serial Bus
External
Reference
Buffer
12.8MHz VCXO
Feedback Buffer
Reference Switch
Ext_Ref_Det
Ext_Ref_Lock_Detect
Digital Switch
OFF / ON ON / OFF
RF Switch
Ext_Ref_Ctrl
Buffer Buffer
FCL Reference Receiver Synthesizer Reference Digital Clock Synthesizer Reference
Internal/External Reference Clock Branch