Contents
iii
CG635 Synthesized Clock Generator
Phase Noise Tests
56
Jitter Tests
58
Timebase Calibration
59
Timebase Calibration Test
60
Calibration 60
Circuit Description
61
Overview 61
Accuracy 61
Resolution 61
Phase Noise
61
Circuit Block Diagram
62
Timebase 62
Reference Synthesizer
62
Reference Synthesizer Clean-up
63
Time Modulation
63
RF Synthesizer
63
Programmable Dividers and Clock Fan-out
64
Determining Register Values
64
Phase adjustment
67
Detailed Circuit Description
69
Timebase 69
DDS and the 19.40/19.44 MHz Reference
71
Time Modulation
73
RF Synthesizer
74
ECL Dividers and Clock Multiplexer
75
Microcontroller 76
Rear-Panel RJ-45 Outputs
82
RS-232 and GPIB Interfaces
83
Power Supply Interface
83
Front-Panel Output Drivers
83
Front-Panel Q and Q
¯ Drivers
84
Front-Panel CMOS Driver
84
Front-Panel Display and Keypad
85
Power Supply
85
Timebase Options
86
Optional PRBS Generator
86
Line Receiver Accessories
87