JVC RX-508VBK Service Manual page 20

RX-508VBK RX-508VBK
RX-5O9VTN RX-SO9VTN
Wi LA3401 (IC105): FM MPX Detector
1. The main function descriptions
(1) Detect the FM Multiplex Signal (Stereo signal ).
(2) When receiving FM Stereo Signal, it outputs the signal for indicator. 1. Explanation of the operation
(3) AM/FM Audio Amplifier. Audio signal is input to LPF1 to reduce the high frequency components. The output from LPF1 is
coded to 1 bit signal by ADM modulator and comparator with inside .This digital signal is input to
HE M50198P(1C602) : Digital Delay IC
2. Terminal Layout 3. Top View & Block Diagram 4 Toe main contro! logic. And this signa! obtain various effect,and is written in SRAM .At the same time
ts Steno ! Hi 2S oft t main contro! logic read the data from SRAM ,and input it to ADM demodulator .The ADM
demodulator converts 1bit signal to analog signal. The analog signal is input to LPF2 to reduce the
os '"e cont i ts,and Pin 13 "
vec VEO LPF LUPE in LPF LPF in Cont STEREO GND suprius components,and output to Pin 1 3 .
am InC]1 220) Vee ee AA. 9 ed ee -A iis ;
ena 3 Bae I Fr. | RREO TT . od LPF1 Reject the high frequency components which is contained the input signal and
sepaans.j4 19 LI LPF 1 | Pitot et. | 1 (MONO + HY i unnecessary.
courtjs = 18f Pliny | LPF2 Reject the suprius components which is generated by the ADM demodulation by usin
(Ge
Bur
tJ
Trigger I
with comparator.
es
RQ? 16 LPF °
Pee cell | = thn Reactance | OP1,CC1 For ADM modulator.
rwamCiio i3Esterco zm ! OP2,CC2_ For ADM demodulator.
aot P| Deel |] |
TN 1 2. Terminal Layout 3.P in function
1a ! ,
a B a l a . A
i? Dp | mot Base [ET smit| —rantin [|
aan = = a Bs
I rattan [Lae] a Bor LL ove | Powersupply | 12 | wan | Ompuroturr _|
i 1 ! = Foran | 2.| xm _[Oxelation Terminal] 14 | vm | inpuroftpr |
L e ) tea ! oa Bjorm | |_xour [osatation Terminal] 15] orovt_| Integrator ovtput |
i =—a Muting I oa = a | 4 | per | Delaytimecontro! | 16 { opin | Integrator input
wa HES lexi] | ee a CO
1 wom) od oats Fa opm Ce De
anes BT ET EO er ere a nt ware F3 or our Ee ee de
AM An- SEMIN wee irets boy (Poss mmme? «Rieu aeceoe Change eee: D-GNO PIN | 8 |ucomasy| ConnectedtoGND | 20{ orm | Integrator input
[9 | mre | +f 21 crour_| integrator output _|
} 10} mmme | | «df 22 { wour | outputofter |
| ecwo fot 23 ew [input of iPr |
| acu | ee Ee | _ Powersupply _|
A-GND 73] LP OUT
4. Pin Function Description [rnno.] symbol] SSC and opens Sd
f 1 | amin [tt | Input terminal for AM detection signal.
| 2 [ FMin | 1 | Input terminal for FM detection signal.
[| 3 [{ PILOT OUT | O {Output of MPX pilot signal (Connect to Pin18).
| 4 | Sepa. ads. | - [Separation adjustment.
| _L-out | Left channel signa! output.
Ea
L- out | 0 |
[ 0 [Reversal omput of Pins.
7 [RO [Reversal ouput of Pn
[Rew [oO | Right channel signal out SS
| MUTE CONT | — [The mute time is controlled by the connected capacitor when turning the power switch on.
| FM/AM | 1 [Changeover the FM/AM input. "H":AM, —"L": FM
Puget
[end | = |eround termina Sd
[tenes To | stereo indicator ouiput Stereo", Mone SCSCSCSCSCSCSCS~*S
| 14 [MuTE CONT | - | The mute time is controlled by the connected capacitor when changing over the FM/AM .
| 15 | MUTEIN | 1 | Mute signal input."H": Mute on, —_"L" : Mute off.
PF | - |
LPF [ - |
PF =
PF | - |
cof i |
Vec i - |
[3s |__| [low pass Fiter of plot deteaor ——OSOSOSCSCSCSCSCSCSCSCS~S
[17 [rr] = wile tis terminal goes to "He VO Rep OSS
RS GA
3]
[20]
Power supply.
ul
[21 fj vco |
p22 vec |