Combined Use Of Int And Ll Modes In A Single System - Sony SS-HQ1 Application Notes

12.2.5. Combined Use of INT and LL Modes in a Single System

To switch between INT (internal) and LL (line lock) in a single set, we recommend the three switching systems
presented below. The main differences between these switching systems are summarized in Table 12.2-15.
• ECK-27MHz INT / ECK-27MHz LL switching system (set automatically; no external circuit)
This system uses the internal detector for automatic recognition (auto mode) in order to switch
between INT and LL. With this system, ECK input is always operated at 27MHz, regardless of
whether INT or LL is used.
• ECK-28MHz INT / ECK-27MHz LL switching system (set manually; DIP switch change)
This system switches (manually) between LL and INT depending on whether a DIP switch is set to
"High" or "Low". ECK input must be switched in each mode (INT/LL). (We provide the block diagram
of this system by Ver1.2.0.)
• ECK-28MHz INT / ECK-27MHz LL switching system (set automatically; external circuit required)
This system uses an external circuit to automatically detect whether there is an external VD input and
automatically switches between LL and INT. ECK input must be switched in each mode (INT/LL). (We
provide the block diagram of this system by Ver1.2.0.)
Table 12.2-15 Main Differences Between Switching Systems
System
Difference
ECK
X'tal
Sub-carrier
in INT mode
PLL
in INT mode
RESET operation
each time system is
switched
External VD
detection circuit
Use of Auto mode
ECK-27MHz INT /
ECK-27MHz LL
Switching system
(set automatically)
Always 27MHz
Free-run
Required
(X'tal oscillation)
Not required
Not required
Possible (required)
ECK-28MHz INT /
ECK-27MHz LL
Switching system
(set manually)
27MHz/28MHz
Switching required
Locked
Not required
Required
Not required
Not possible
199
- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
ECK-28MHz INT /
ECK-27MHz LL
Switching system
(set automatically)
27MHz/28MHz
Switching required
Locked
Not required
Required
Required
Not possible