Sansui 5900Z - Page 6

5900Z/4900Z/390024
3.
INTERIOR
BLOCK
DIAGRAM
OF
IC
3-1.
LC7207
(FM
AM
Electronic
Tuning
Controller
IC)
VSS
CVin 11
Manu
Tune
12
S-Curve
FM 5
ow
MW
6
3
TEST
a
LW 7 n
F/A
out
8
a
M-U/D
M/L out 9 as
MEMO
CH1 36
MANU
CH2 37
2)
S
UP
CH3
38
z
=
3
3
o
“7
DOWN
CH4
39
ie
g
ia)
=
oO
Oo
2
CHS 40 i
s)
3. 3 br UP
é .: /DOWN
CH6
4)
x
Counter
a
o
CH7 42 3 19 DX-LO
3
g
22
MUTE
CR2 2
e
3 BUC 23 F-Tune
Table.
3-1
Function
and
Operation
of
Each
Pin
Pin
Input/
Description
of
Function
and
Pin
Input/
Description
of
Function
and
No.
Output
Operation
No.
Output
Operation
1
{CRI
Input/
|
To
this
pin,C
and
R
are
connected
7
|
LW
Input
LW
band
select
pin
Output
|
for
a
clock
pulse
generator.
At
H
level,
no
band
selection
is
made.
2
i
CR2
Input/
To
this
pin,C
and
R
are
connected
At
L
level,
LW
band
is
selected.
Output
|
for
a
timer
to
control
a
pulse
|
width
of
MUTE
pin
output
signal
8
|
F/AOUT
|
Output
|
Indicator
control
signa
Output
pin
|
when
the
band
selector
is
tuned.
H
level:
FM
band
L
level:
AM
band
3
|
BUC
Input
Memory
back
up
function
is
ope-
rated
by
this
input
pin.
9
|
M/L
OUT
Indicator
control
signd
Output
pin
At
H
level,
the
function
is
not
ac-
H
level:
MW
band
tuated.
L
level:
LW
band
At
L
level,
the
function
is
ac-
se
tuated.
10
|
CV
OUT
Output
|
Voltage
for
variable
capacitance
diode
from
internal.
inalog
signal
4
{TEST
Input
Test
mode
control
pin
for
internal
transfer
gate
comes
@ut
to
this
LSI
circuit.
output
pin.
At
H
tevel,
LSI
is
normal
opera-
tion
mode.
141
|
CVIN
Input
This
pin
is
an
input
of
analog
sig-
At
L
level,
LSI
is
fixed
to
test
nal
transfer
gate,
ando
btains
out-
mode.
put
voltage
of
exterml
ladder
re-
sistor.
5
|FM
Input
FM
band
select
pin
=
At
H
level,
no
band
selection
ts
12
This
pin
is
an
input
of
analog
sig-
mode.
nal
transfer
gate,
ando
btains
out-
At
L
level,
FM
band
is
selected.
put
tuning
voltage
tom
manual
tuning
volume.
6
|MW
Input
MW
band
select
pin
At
H
level,
no
band
selection
is
13.
|
S<urve
S-curve
voltage
from
AM
or
FM
made.
is
fed
to
this
input
pn
,
and
inter-
At
L
level,
MW
band
is
selected.
nal
window
comparaol
generates
voltage
required
fromAmFC
circuit.