(No.22036)1-29
4.6 LA1838 (IC1) : FM AM IF amp & detector, FM MPX decoder
• Block Diagram
• Pin Function
ALC
BUFF
AM
OSC
REG
AM
MIX
FM
RF.AMP
AGC
AM IF
DET
SD
COMP
AM
S-METER
FM
S-METER
FM IF
PM
DET
S-CLRVE
AM/FM
IF-BUFF
TUNING
DRIVE
GND
VCC
STEREO
DRIVE
MUTE
DECODER
ANIT-BIRDIE
STEREO
5N
SW
P-DET
PILOT
DET
FF
19k
FF
19k
FF
38k
VCO
384KHz
/
2
/
LS
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
1
2
3
4
6
7
8
9
10
11
12
13
14
15
5
Pin No.
Symbol
I/O
Function
1
FM IN
I
This is an input terminal of FM IF signal.
2
AM MIX
O
This is an out put terminal for AM mixer.
3
FM IF
I
Bypass of FM IF
4
AM IF
I
Input of AM IF Signal.
5
GND
-
This is the device ground terminal.
6
TUNED
O
When the set is tunning,this terminal becomes "L".
7
STEREO
O
Stereo indicator output. Stereo "L", Mono: "H"
8
VCC
-
This is the power supply terminal.
9
FM DET
-
FM detect transformer.
10
AM SD
-
This is a terminal of AM ceramic filter.
11
FM VSM
O
Adjust FM SD sensitivity.
12
AM VSM
O
Adjust AM SD sensitivity.
13
MUTE
I/O When the signal of IF REQ of IC121(LC72131) appear, the signal of FM/AM IF output. //Muting
control input.
14
FM/AM
I
Change over the FM/AM input. "H" :FM, "L" : AM
15
MONO/ST
O
Stereo : "H", Mono: "L"
16
L OUT
O
Left channel signal output.
17
R OUT
O
Right channel signal output.
18
L IN
I
Input terminal of the Left channel post AMP.
19
R IN
I
Input terminal of the Right channel post AMP.
20
RO
O
Mpx Right channel signal output.
21
LO
O
Mpx Left channel signal output.
22
MPX IN
I
Mpx input terminal
23
FM OUT
O
FM detection output.
24
AM DET
O
AM detection output.
25
AM AGC
I
This is an AGC voltage input terminal for AM
26
AFC
-
This is an output terminal of voltage for FM-AFC.
27
AM RF
I
AM RF signal input.
28
REG
O
Register value between pin 26 and pin28 besides the frequency width of the input signal.
29
AM OSC
-
This is a terminal of AM Local oscillation circuit.
30
OSC BUFFER
O
AM Local oscillation Signal output.
Содержание CA-UXP55
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