PC1876
DESCRIPTION
The
PC1876 is an integrated circuit for US MTS (Multi Channel Television Sound) system. All functions for US
MTS system are provided on one chip. The
PC1876 has built-in SAP (Sub Audio Program) discrimination error
protection circuit.
FEATURES
BTSC (USA) standard demodulator (Stereo demodulation and TV-dbx noise reduction)
Only four adjustments (2 separation, 1 stereo VCO, 1 filter)
Supply voltage: 8 V to 10 V
Circuit current: 27 mA TYP. (Supply voltage: 9 V)
Input and output level (L+R, 100% modulation)
Input level: 0.42 V
p-p
Output level: 1.41 V
p-p
APPLICATION
TV sets and VCRs for North America
ORDERING INFORMATION
Part Number
Package
PC1876GT
42-pin plastic SSOP (9.53 mm (375))
The
PC1876 is available only to licensees of THAT Corporation.
Please contact: (03) 5790-5391 (Japan)
(508) 229-2500 (USA)
US MTS DECODER
The mark shows major revised points.
1996
DATA SHEET
BIPOLAR ANALOG INTEGRATED CIRCUIT
Document No. S11666EJ4V0DS00 (4th edition)
Date Published June 2000 N CP(K)
Printed in Japan
The information in this document is subject to change without notice. Before using this document, please
confirm that this is the latest version.
PC1876
3
Data Sheet S11666EJ4V0DS00
BLOCK DIAGRAM
Notes 1. Do not leave the Internally Connected (IC) pin open because it is a base-open pin. Connect this pin to V
CC
or GND.
2. Am: Amplitude modulation (Carrier frequency is 31.5 kHz (2fH))
Remark Use the following for external parts.
Resistor (
) : Metal film resistor (
1%). Unless otherwise specified;
5%
Capacitors (
) : Tantalum capacitor (
10%). Unless otherwise specified;
20%
Variable resistors:
10%
ROT
V
CC
1 k
24
25
26
LED
Driver
Mode
Selector
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
Matrix
Offset
Absorp-
tion
Wide-
Band
RMS
Wide-
Band
VCA
Wide-
Band
RMS
Filter
f
H
Trap
LPF
Spectral
RMS
Filter
Spectral
RMS
2.19 kHz
LPF
408 Hz
LPF
Stereo
VCO
De-
emphasis
SAP
VCO
Note 2
Note 1
L-R
AM
Demodulator
L+R
LPF
Pilot
Discrimination
Phase
Comparator
Stereo
LPF
Stereo
Phase
Comparator
Pilot
Canceller
+
Phase
Detector
SAP
LPF
Loop
Filter
SAP
Detector
SAP
BPF
Noise
BPF
Noise
Detector
ST/SAP
SW
SAP1/2
ST/SAP
MUTE
FMONO
IC
LOT
10 F
10 F
+
1 F
+
0.1 F
22 F
+
1.5 V
33 k
SAPVA
10 k
33 k
1 k
47 k
0.1 F
20 k
+
1 F
4.7 F +
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
1 k
V
CC
V
CC
20 k
10 F
+
3.3 F
WTI
51 k
100 k
51 k
50 k
56 k
56 k
5.1 k
3 k
+
+
1 F
V
CC
0.1 F
0.1 F
68 k
0.47 F
+
0.047 F
0.01 F
2.2 F
+
+
+
STL
GND
MOA1
MOA2
FLTA
STI
DCO
SAPL
LGND
1 F
SPA
WBA
ITI
WRB
SRB
V
CC
WBVI
VEO
fHSW
SI
SOT
NDT
SDT
SDI
SBO
COM
1/2
V
CC
1/2
1/4
VRE
STVA
PD1
PD2
D1
D2
VOA
23
Variable
Emphasis
22
PC1876
4
Data Sheet S11666EJ4V0DS00
PIN CONFIGURATION (Top View)
42-pin plastic SSOP (9.53 mm (375))
PHASE COMPARATOR FILTER 2
COMPOSITE SIGNAL INPUT
1
42
D2
COM
PHASE COMPARATOR FILTER 1
SAP BPF OUTPUT
2
41
D1
SBO
PILOT DISCRIMINATION FILTER 2
SAP DISCRIMINATION FILTER INPUT
3
40
PD2
SDI
PILOT DISCRIMINATION FILTER 1
SAP DISCRIMINATION FILTER
4
39
PD1
SDT
STEREO VCO SETTING
NOISE DETECTION FILTER
5
38
STVA
NDT
FILTER ADJUSTMENT
6
37
FLTA
SAP VCO SETTING
SAP SINGLE OUTPUT
7
36
SAPVA
SOT
SAP SINGLE INPUT
8
35
1.5 V
SI
MONAURAL OFFSET ABSORPTION 1
9
34
VRE
VCA OFFSET ABSORPTION
STEREO VCO FREE-RUN MONITOR SWITCH
10
33
MOA2
fHSW
SIGNAL GND
VARIABLE EMPHASIS OUTPUT
11
32
MOA1
VEO
WIDE-BAND VCA INPUT
12
31
GND
WBVI
L CHANNEL OUTPUT
POWER SUPPLY (9 V)
13
30
VOA
V
CC
R CHANNEL OUTPUT
SPECTRAL RMS OFFSET ABSORPTION
14
29
LOT
SRB
WIDE-BAND RMS OFFSET ABSORPTION
15
28
ROT
WRB
F-MONAURAL SELECTION
TIMING CURRENT SETTING
16
27
IC
ITI
MATRIX MUTE
WIDE-BAND RMS SETTING
17
26
FMONO
WBA
STEREO/SAP SWITCH
SPECTRAL RMS SETTING
18
25
MUTE
SPA
SAP 1/2 SWITCH
SPECTRAL RMS TIMING
19
24
ST/SAP
STI
STEREO LED DRIVER/
STEREO VCO FREE-RUN MONITOR
WIDE-BAND RMS TIMING
20
23
SAP1/2
WTI
LED GND
21
22
STL
LGND
DCO
SAPL
DC OUTPUT
SAP LED DRIVER
INTERNAL CONNECTION
MONAURAL OFFSET ABSORPTION 2
BIAS (1.5 V)
1/2 V
CC
FILTER
PC1876
5
Data Sheet S11666EJ4V0DS00
CONTENTS
1.
INTERNAL EQUIVALENT CIRCUITS ............................................................................................
6
2.
FUNCTION OF EACH BLOCK ..................................................................................................... 13
2.1 Stereo Demodulation Block ................................................................................................... 14
2.2 SAP Demodulation Block ....................................................................................................... 15
2.3 dbx Noise Reduction Block ................................................................................................... 15
2.4 Matrix Block ............................................................................................................................ 17
3.
EXPLANATION OF EACH FUNCTION ........................................................................................ 18
3.1 Mode Matrix Table ................................................................................................................... 18
3.2 MATRIX MUTE Pin .................................................................................................................. 18
3.3 F-MONAURAL SELECTION Pin ............................................................................................. 19
3.4 STEREO/SAP SWITCH Pin ..................................................................................................... 19
3.5 SAP 1/2 SWITCH Pin ............................................................................................................... 19
4.
PRECAUTIONS ............................................................................................................................... 20
4.1 Impedance of Input Pins and Output Pins ........................................................................... 20
4.2 Output Load Impedance ........................................................................................................ 20
4.3 Cautions on External Components ....................................................................................... 21
4.4 Change of Electrical Characteristics Depending on External Components ..................... 21
4.5 BIAS (1.5 V) Pin ....................................................................................................................... 21
5.
ADJUSTMENT PROCEDURE ........................................................................................................ 22
5.1 Stereo VCO Adjustment ......................................................................................................... 22
5.2 Filter Adjustment .................................................................................................................... 22
5.3 Separation Adjustment .......................................................................................................... 22
5.4 SAP VCO Adjustment ............................................................................................................. 23
5.5 List of Pin Settings in Adjustment ........................................................................................ 23
6.
ELECTRICAL SPECIFICATIONS ................................................................................................... 24
7.
MEASURING CIRCUIT ................................................................................................................... 35
8.
DIFFERENCES BETWEEN THE
PC1876GT AND
PC1872GT ............................................. 36
9.
PACKAGE DRAWING ..................................................................................................................... 37
10. RECOMMENDED SOLDERING CONDITIONS ............................................................................. 38
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