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ICs for TV
AN5637
SECAM decoder IC
I Overview
The AN5637 is a chroma signal processing circuit
for use in SECAM system. It outputs the color dif-
ference signal.
19.2±0.3
16
9
Unit : mm
I Features
• Built-in bell filter, deemphasis circuit
• One point adjustment
• Small number of external components
1
8
I Applications
• SECAM system TV
(0.71)
Seating plane 2.54
0.5±0.1
1.22±0.25
7.62±0.25
3°
to
15°
0.30+–00.1.005
DIP016-P-0300D
Note) The package of this product will be changed to lead-free type
(DIP016-P-0300M). See the new package dimensions section
later of this datasheet.
Publication date: December 2001
SDB00021BEB
1
AN5637
I Electrical Characteristics at VCC = 9 V, Ta = 25 °C (continued)
Parameter
Symbol
Conditions
Min Typ Max Unit
Demodulator/Output (continued)
Typical input : (Pin16) Color bar signal (Composite) 1 V[p-p],
(Pin15) Sand castle pulse,
(Pin1) 4.43362 MHz sine wave 350 mV[p-p], V-BLK period
Blanking period
output DC voltage
SN ratio *3
VBLK
S/N
Stable sine wave is necessary
in V period (4.4336 MHz)
Amplitude ratio when
Deviation = 460 kHz/0 kHz
(Pin10 measurement)
2.2 2.7 3.2
30
V
dB
Residual high frequency amplitude
VRH Harmonic content with 100 %
white signal input
(Pin10 measurement)
10 mV[p-p]
Output impedance
(when SECAM) Pin9
ZOS9 DC measurement, Pin1 = 5 V
260 460 660 Ω
Output impedance
(when non SECAM) Pin9
ZON9 DC measurement, Pin1 = 1.5 V 1 MΩ
Output impedance
(when SECAM) Pin10
ZOS10 DC measurement, Pin1 = 5 V
260 460 660 Ω
Output impedance
(when non SECAM) Pin10
ZON10 DC measurement, Pin1 = 1.5 V 1 MΩ
Sand castle pulse
Typical input : (Pin1) 4.43362 MHz sine wave 350 mV[p-p], V-BLK period
Horizontal and vertical BLK level *4 VBL Measurement of slice level of H, 0.5 1 1.5 V
V blanking pulse
Burst gate level *5
VBG Measurement of slice level of
burst gate pulse
3.4 3.9 4.4 V
Reference signal/interface
Typical input : (Pin1) 4.43362 MHz sine wave 350 mV[p-p], V-BLK period
Reference signal amplitude
Vref Amplitude range of sine wave
(4.43362 MHz) of Pin1 input
0.20 0.50 V[p-p]
System SW discrimination level
VSS Voltage when Pin10 becomes
2.5 3.0 3.5
open if Pin1 is 5 V to 1 V variable
V
IDENT
Typical input : (Pin16) Color bar signal (Chroma), (Pin15) Sand castle pulse,
(Pin1) 4.43362 MHz sine wave 350 mV[p-p], V-BLK period
Color On/Off hysteresis
HC Difference between color turn On 0.5 2 6 dB
or Off and Off to On level
Killer sensitivity
K Color turn Off level when disc-
rimination signal changes
150 mV[p-p] to 0 mV[p-p]
−32 dB
Note) *3 : Refer to "Explanations of testing method 3"
*4 : Refer to "Explanations of testing method 4"
*5 : Refer to "Explanations of testing method 5"
SDB00021BEB
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I Application Circuit Example
AN5637
Note) The following signal is inputted to Pin1 from the AN5192/95.
• System discrimination
1. Pin1 is the input and output pin for the three pieces of information
(1) Reference frequency signal input pin (AC)
(2) System discrimination signal input pin (DC voltage)
(3) SECAM/Non-SECAM discrimination output pin (DC current)
AN5637
System discrimination
SECAM
Non-SECAM
Pin1 input
DC voltage
"H" (4.6 V)
"L" (1.3 V)
"H" (4.6 V)
"L" (1.5 V)
Pin1 sink current
175 µA
175 µA
0 µA
0 µA
Pin9, 10 output
Color difference signal output
Open
DC voltage output
Open
2. Reference frequency signal
The reference frequency signal input for Pin1 is used for the following 4 signals ;
(1) Bell filter automatic adjustement
(2) PLL(VCO) automatic adjustement
(3) Deemphasis automatic adjustement
(4) Ident discrimination
Be sure to input the high precision PAL carrier signal (4.43362 MHz) only in the vertical retrace period.
SDB00021BEB
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