
LA75520KVA
No.A0654-5/12
System changeover
a. SIF system SW
The SIF system can be changed over by setting A (pin 7) and B (pin 9) to GND and OPEN respectively.
A
B
BG
I
DK
MN
FM DET
LEVEL
De-emphasis
GND
O
6dB
75
μs
GND
OPEN
O
0dB
50
μs
OPEN
GND
O
0dB
50
μs
OPEN
O
0dB
50
μs
Note : Circles mean that the system indicated with a circle is selected
b. IF system SW
The IF frequency becomes 38.9MHz when pin 10 is open.
The IF frequency becomes 38.0MHz when pin 10 is set to GND.
The IF frequency becomes 39.5MHz when pin 10 is set to VCC.
c. Split/inter carrier SW
Inter-carrier is selected by setting the 1st SIF input (pin 13) to GND.
d. Reference frequency changeover SW
The reference frequency becomes 4.43MHz when pin 11 is OPEN.
The reference frequency becomes 4.0MHz when 270k
Ω is connected between pin 11 and GND.
e. AFT mute level, trap point shift SW
By changing the pin 15 voltage, the potential and TRAP point at which AFT is muted can be set to either just or shift
(about +220kHz).
Pin 15 potential
AFT mute potential
TRAP point shift
VCC to 4V
MIDDLE (VCC/2)
Just
4V to 2.5V
MIDDLE (VCC/2)
Shift
2.5V to 1V
HI (VCC)
Just
1V to GND
HI (VCC)
Shift
* VCC=5V
f. FM detector function not used
To stop FM detection VCO without using the SIF circuit, short-circuit pin 1 – GND with resistance of 1k
Ω or less.