TEMIC U4935B

U4935B
SECAM Decoder
Description
The U4935B is an SECAM decoder designed for use with
the PAL/NTSC TV baseband processor U4930B and the
baseband delay line U3665M.
The circuit includes a bell filter, a demodulator and an
identification circuit. A signal with stable reference frequency for calibration and a three-level sandcastle pulse
for blanking and burst gating are required.
The IC is realized in a bipolar VLSI technology and
operates with +8 V supply voltage. Easy interfacing and
few external components support the design of a
multistandard TV.
Features
Package
D Fully integrated and auto-tuned filters
D Minimum number of external components
D Easy interfacing with the TV baseband processor and
16-pin dual in-line plastic (DIP16)
the switched capacitor baseband delay line
Block Diagram
VS = 8 V
0.1 m F
Bell filter
out
PLL
auto2
2
CVBS 16
in
Bell
filter
ref 7
AMP
Ident
Interface
PLL
tuning
fref/
ident
5
Killer
out
22 m F
3
Bandgap
Bell-filter
tuning
1
13
12
Bell
filter
ACC
0.1 m F
PLL
auto1
0.47 m F
4 Band
gap
PLL
De–
emphasis
SECAM
sw.
B –Y
output
10 – (B–Y)
out
R –Y
output
9 – (R–Y)
out
Pulse
gen.
8
PLL
ref
15
SCP
in
6
GND
14
Black
adj. R
11
Black
adj. B
96 11715
Figure 1. Block diagram
Ordering Information
Extended Type Number
U4935B-ADP
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
Package
DIP16
Remarks
1 (16)
Preliminary Information
U4935B
Pin Description
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Symbol
fref / ident
Bell out
VS
Band gap
Killer out
GND
Bellref
Function
fref / ident
Bell-filter output
8-V supply voltage
Band-gap reference voltage
SECAM killer output
Ground
Bell-filter reference
voltage output
PLLref
PLL reference
–(R–Y)
–(R–Y) output
–(B–Y)
–(B–Y) output
Black adj. B Black level adjust B - channel
PLL1
PLL auto 2
PLL2
PLL auto 1
Black adj. R Black-level adjust R - channel
SCP
Sandcastle pulse input
CVBS
CVBS input
fref / ident
1
16
CVBS input
Bell filter
output
2
15
SCP input
VS
3
14
Black adj. R
Band gap
4
13
PLL auto 1
*
U4935B
SECAM
killer out
5
12
PLL auto 2
GND
6
11
Black adj. B
Bell filter
ref
7
10 – (B–Y) output
PLL ref
8
9
– (R–Y) output
9611726
Figure 2. Connection diagram
Absolute Maximum Ratings
VS = 8 V, Tamb = 25°C, reference point Pin 6, unless otherwise specified
Test conditions: Vpin 1 = 4.75 V, Vpin 16 = 4 V, unless otherwise specified
Parameters
Supply voltage
Junction temperature
Storage temperature range
Electrostatic handling*)
Pin 3
all Pins
Symbol
VS
Tj
Tstg
VESD
Value
8.0
125
–40 to +125
200
Unit
V
°C
°C
V
Symbol
VS
Tamb
Value
7.5 to 8.5
–20 to +70
Unit
V
°C
Symbol
RthJA
Value
80
Unit
K/W
*) Equivalent to discharging a 200 pF capacitor via a 0-W resistor
"
Operating Range
Parameters
Supply voltage range
Ambient temperature
Pin 3
Thermal Resistance
Parameters
Junction ambient (when soldered to PCB)
2 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
Power dissipation Pd ( mW )
1500
1250
1000
750
500
250
0
0
96 11702
25
50
75
100
125
150
Ambient temperature Tamb ( °C )
Figure 3. Thermal derating curve of the package
(maximum rating)
Electrical Characteristics
VS = 8 V, Tamb = 25°C, reference point Pin 6, unless otherwise specified
Test conditions: Vpin 1 = 4.75 V, Vpin 16 = 4 V, unless otherwise specified
Parameters
DC supply
Supply voltage VS
Supply current IS
Test Conditions / Pins
Symbol
Min.
Typ.
Max.
Unit
Pin 3
Pin 3
VS
IS
7.5
18
8.0
24
8.5
30
V
mA
f = 4.0 - 5.0 MHz sweep
signal with 20 mV
peak-to-peak amplitude at
the CVBS input
(see note 2, page 5), Pin 2
f = 4.0 - 5.0 MHz sweep
signal with 20 mV
peak-to-peak amplitude at
the CVBS input,
Pin 2
fBO
4.236
4.286
4.336
MHz
fBW
250
320
368
kHz
DVRB
VO
2.1
–15
2.8
3.5
+15
V
mV
DVBB
–50
+20
mV
VR–Y
0.85
1.0
1.15
V
VB–Y
1.05
1.24
1.36
V
Note 1
Bell filter
Resonance frequency
Bandwidth
Demodulator
Output DC level during blanking
Black level error –(R–Y)
Black level error –(B–Y)
–(R–Y) output signal amplitude
(peak-to-peak value)
–(B–Y) output signal amplitude
(peak-to-peak value)
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
Pins 9 and 10
Black/ white signal at the
CVBS input
(see note 4, page 5), Pin 9
Black/ white signal at the
CVBS input
(see note 4, page 5), Pin 10
(see note 1, page 5), Pin 9
(see note 1, page 5), Pin 10
3 (16)
Preliminary Information
U4935B
Parameters
Ratio of –(B–Y)/–(R–Y) output
signal amplitude
Linearity
Test Conditions / Pins
Symbol
VB–Y/VB–
Min.
1.10
Typ.
1.24
Max.
1.36
(see notes 1 and 3, page 5)
VLIN
2.6
Pin 10
Sandcastle pulse (see figures 16 and 17)
Vertical blanking detection level
Pin 15
VVB
1.0
Horizontal blanking detection level
Pin 15
VHB
1.75
Burst-gate detection level
Pin 15
VBG
3.5
Reference/ Identification
Reference frequency
During vertical blanking
fref
(see figure 4, 300 mVpp)
Pin 1
System switches detection level
Vext1 = variable
VTH1
(at SECAM)
(see figure 6),
Pin 1
System switches detection level
Vext1 = variable
VTH2
1.5
(at no SECAM)
(see figure 6),
Pin 1
Sink current (at SECAM)
(see note 5, page 5), Pin 1
125
Pin 5 voltage (at SECAM)
(see note 1, page 5), Pin 5
V5S
2.4
Sensitivity of identification and
Attenuate the amplitude
I/K
–46
killer
(see notes 1 and 6, page 5)
Pin 5
Unspecified characteristics (only for reference but not guaranteed limiting values)
Input dynamic range
Pin 16
VDR
(peak-to-peak value)
Chrominance input voltage
(see note 7, page 5), Pin 16
VCL
(peak-to-peak value)
Pole frequency of the de-emphasis
fp
LPF
Ratio of the pole and zero
fp/fo
frequency
–(R–Y), –(B–Y) output impedance
Pins 9 and 10
Zo1
(at SECAM)
–(R–Y), –(B–Y) output impedance
Pins 9 and 10
Zo2
1
(at no SECAM)
Reference voltage amplitude
(see note 8, page 5), Pin 1
Vref
0.2
(peak-to-peak value)
Rising edge of SECAM burst-gate
(see note 9, page 5)
Tr
pulse (internal generated)
Falling edge of SECAM burst-gate
(see note 10, page 5)
Tf
pulse
2.9
3.2
1.25
2.0
3.85
1.4
2.25
4.2
Unit
Y
4 (16)
Preliminary Information
4.4336
2.9
V
V
V
MHz
3.3
2.0
V
V
180
3.1
–38
235
3.6
–32
mA
1.0
1.4
V
167
300
mV
85
V
dB
kHz
3
200
600
W
MW
0.57
V
4.5
ms
0.2
ms
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
Notes:
1.
2.
3.
4.
CVBS input: 100/75 color bar signal. The (B–Y) burst signal [fOB] amplitude is 167 mVpp (= 0 dB).
Measure during scanning. An active probe is recommended for low capacitive loading.
Defined as VLIN = b / a (see figure 4).
Measure the difference between the blanking (V1) and the black level (V2) (see figure 5).
DVRB = V2 - V1 (Pin 9), DVBB = V2 - V1 (Pin 10)
a
V2
b
V1
96 11720
96 11719
Figure 4. VLIN
Figure 5. Black level error at Pin 9 (R–Y)
5. The external voltage at Pin 1 should exceed 0.5 V.
6. VK (peak-to-peak value of the burst signal in a blue line) when “LOW” (0.2 V) at Pin 5 related to 167 mVPP ( = 0 dB)
I / K = 20 log10 (VK / 167 m V) [dB]
7. Measured in the burst period of a blue line
8. The reference frequency should be stable during the vertical blanking
9. Defined as the time from rising edge of the sandxastle burst-gate pulse at Pin 15.
10. Defined as the time from falling edge of the sandxastle burst-gate pulse at Pin 15.
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
5 (16)
Preliminary Information
U4935B
Internal Pin Configuration
VCC
9611727
300 m A
2W
4.3 V
1
2.8 V
2 kW
2 kW
18 k W
13 k W
4.3 V
10 pF
100 W
5
15.1 k W
20 k W
96 11730
100 m A
Figure 9. SECAM killer output
7
96 11733
Figure 6. fref / ident
VCC
100 W
20 k W
2
20 k W
100 m A
100 m A
96 11728
Figure 7. Bell-filter output
Figure 10. Bell-filter reference
8
VCC
2 kW
2 kW
4
1.8 k W
200 mA
9 kW
12.6 k W
96 11734
Figure 11. PLL reference
96 11729
Figure 8. Band gap
6 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
Internal Pin Configuration (continued)
96 11738
50 m A
9, 10
50 m A
50 m A
mA
230
15
96 11735
100W
Figure 12. –(R–Y), –(B–Y) output
Figure 15. Sandcastle input
14
4
4.3 V
670 W
13 pF
225 W
16
8.1 k W
1.11 kW
200 m A
13.6 kW
2.5 k W
2.8 V
8.1 k W
200 m A
100m A
96 11739
11
96 11736
Figure 13. Black level adjust –(B–Y), –(R–Y) channel
13
Figure 16. CVBS input
12
200 m A
200 m A
96 11737
Figure 14. PLL auto 1, 2
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
7 (16)
Preliminary Information
U4935B
Functional Description
Bell Filter
The ACC amplifier provides a C- (chrominance) signal of
a constant peak-to-peak level for the bell filter. The bell
filter is of a gyrator-capacitor type. The resonance
frequency is
4.433619 MHz
4.286 MHz
4.33 MHz
The reference frequency should be stable during the vertical blanking because it is used to calibrate the filters and
the demodulator. The capacitor C7 should be connected
as close as possible to the ground Pin of the package. If
not, this can result in a resonance frequency error.
during vertical blanking
during scanning
during burst gating.
CVBS
in
VBLK pulse
ACC
16
Bell filter
PLL
fref/
ident
Tuning
Amp
1
7
C7
Gain
9611724
fo
4.286 MHz
fref
4.434 MHz
f
Figure 17. Block diagram of the bell filter
8 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
Demodulator
The bell filter delivers the C signal via a limiter amplifier
to the demodulator. The demodulator is of a phase-locked
loop (PLL) type VCO and a phase-emitter coupled
multivibrator with the limiter output and is fed back to the
VCO. The free-running frequency is adjusted by charging
or discharging the capacitor at Pin 8 during the vertical
blanking and is held during scanning.
Therefore, the IC needs no adjustment to enable constant
operation
The low-frequency de-emphasis is matched to the PLL
and is controlled by the tuning voltage of the PLL.
The capacitor, C8, should be connected as close as
possible to the ground pin of the package. If this is not
ensured, a black-level error for both channels may result.
VBLK pulse
Bell-filter
output
Limiter
De–
emphasis
LPF
to H,
V blanking
VCO
PLL
Tuning
8
C8
PLL
ref
9611721
Figure 18. Block diagram of the demodulator
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
9 (16)
Preliminary Information
U4935B
Identification
The identification circuit is a quadrature-type FM
demodulator which uses the bell filter as a phase shifter.
The resonance frequency of the phase shifter is adjusted
to 4.33 MHz i.e., the frequency between the 4.25-MHz
(B–Y) carrier and the 4.40625-MHz (R–Y) carrier
during burst gating. The output of the ACC is multiplied
with the output of the phase shifter. The sample-and-hold
circuit samples the output of the multiplier during burst
gating and maintains this value outside of the burst-gate
pulse time. The identification and killer detectors
compare the sampled-and-hold voltage with internal
detection levels. Only line identification (and no field
identification) is implemented.
*
*
The identification circuit must communicate with the
System Identification of
the U4930B
Logic Level; Pin 1 of
the U4935B
No PAL
(5 0 V)
HIGH (5.0
PAL
LOW (1.5
(1 5 V)
CVBS
in
ACC
16
U4930B (PAL/NTSC decoder) to guarantee that the output signal from the decoder is available when no PAL
signal has been identified.
If a SECAM signal has been decoded, a request for
“color on” is transmitted to Pin 1 (current sink: 180 mA).
If the signal request is grated (i.e., Pin q is “HIGH”
therefore no PAL), the output signals from the U4935B
are switched on and the output pins of the U4930B have
a high impedance.
If no SECAM signal has been decoded, the outputs of the
U4935B will be blanked or have high-impedance state
depending on the logic level at Pin 1.
(see table 1)
SECAM Identification of
the U4935B
SECAM; 180 mA
no SECAM; 0 mA
SECAM; 180 mA
no SECAM; 0 mA
Bell
filter
Output Pins 9, 10 of
the U4935B
(–R–Y), –(B–Y) signals
Blanked
High impedance
Bell-filter
output
VBLK
BGP
fH
2
S/H
Identification
detector
output
Killer
detector
output
9611722
Figure 19. Block diagram of the identification
10 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
SECAM Switch, Output Stage
The de-emphasis circuit provides the color-difference
signals which are blanked during the horizontal and
vertical blanking pulses. After blanking, the color
difference signals are switched every (B–Y) and (R–Y)
line by the SECAM switch.
The (B–Y) signal is then amplified 3.8 times and
available at Pin 10 after reversing. The (R–Y) signal is
amplified 2.54 times and available at Pin 9. When the
logic level at Pin 1 is “LOW”, the outputs have
high-impedance state.
3.85 V
2.0 V
1.25 V
Pin 15
SCP in
BGP : 3.85 V
HBLK : 2.0 V
VBLK : 1.25 V
fref = 4.433619 MHz
0.2 ~ 0.5 Vp–p
Pin 1
fref / ident
5.0 VDC at SECAM
1.5 VDC at no SECAM
Pin 9
– (R–Y) out
Pin 10
– (B–Y) out
96 11718
Figure 20. Timing waveforms of the output stage
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
11 (16)
Preliminary Information
U4935B
Sandcastle Pulse
The required blanking burst and fH/2 pulses are derived from a three-level sandcastle pulse.
(see figures 16 and 17)
3.85 V
2.0 V
1.25 V
Pin 15
SCP in
HBLK
F/F
(fH/2 pulse)
125 ms
VBLK
SECAM sw
SECAM sw
96 11716
Pin 15 SCP detection level :
BGP : 3.85 V
HBLK : 2.0 V
VBLK : 1.25 V
Figure 21. Timing chart of the internal pulses
0.2 ms
Pin 15
SCP in
SECAM
BGP
4.5 ms
95 11717
Figure 22. Timing chart of the internal SECAM burst gating pulse
12 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
Typical Voltages
Pin
1
Function
DC Voltage
fref / ident
2
3
4
5
Bell-filter output
Supply voltage
Bell-filter ref. voltage output
SECAM killer output
6
7
8
Ground
Bell-filter reference
PLL reference
3.3 V
4.3 V
9
–(R–Y) output
2.8 V
10
–(B–Y) output
2.8 V
11
Black level adjust B - channel
4.16 V
12
PLL auto 2
5.0 V
13
PLL auto 1
5.0 V
14
Black level adjust R - channel
4.28 V
15
16
Sandcastle-pulse (SCP) input
CVBS input
2.05 V
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
1.7 V
8V
4.3 V
3.1 V
0V
Comment
For the - reference input,
- PAL system identification input,
- SECAM killer-signal output.
180 mA typ. at SECAM
0 mA typ. at no SECAM
System switches detection level = 2.9 V.
When SECAM
When no SECAM
The capacitor should be connected as close as
possible to the ground pin of the package.
1.0 V (peak-to-peak value) when the color-bar
signal at Pin 16 is 100/75.
1.24 V (peak-to-peak value) when the color-bar
signal at Pin 16 is 100/75
Black-level error can be compensated by an
external resistor
Capacitor between Pin 12 and Pin 13 improves
color S/N ratio. The value of the capacitor is typ.
0.1 mF.
Capacitor between Pin 12 and Pin 13 improves
color S/N ratio. The value of the capacitor is typ.
0.1 mF.
Black-level error can be compensated by an
external resistor
13 (16)
Preliminary Information
U4935B
VS
10 mF
SCP input
A
0.1 m F
2 kW
5 kW
RR
RB
Vext16 = 4 V
16
15
14
13
12
11
10
9
6
7
8
U4935B
VS
1
2
3
5
4
sw5
150 pF
0.1 m F
22 m F
fref
5 kW
Vext1
0.47 mF
Vext5
=1.5 V
0.47 mF
8.2 k W
VS= 8 V
96 11725
Figure 23. Basic application circuit
14 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
U4935B
Package Information
Package DIP16
20.0 max
Dimensions in mm
19.8 max
7.82
7.42
4.8 max
0.5 min
6.4 max
3.3
1.64
1.44
0.58
0.48
0.39 max
9.75
8.15
2.54
17.78
Alternative
16
15
14
13
12
11
10
9
technical drawings
according to DIN
specifications
96 11709
1
2
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97
3
4
5
6
7
8
15 (16)
Preliminary Information
U4935B
Ozone Depleting Substances Policy Statement
It is the policy of TEMIC TELEFUNKEN microelectronic GmbH to
1. Meet all present and future national and international statutory requirements.
2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems
with respect to their impact on the health and safety of our employees and the public, as well as their impact on
the environment.
It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as
ozone depleting substances ( ODSs).
The Montreal Protocol ( 1987) and its London Amendments ( 1990) intend to severely restrict the use of ODSs and
forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban
on these substances.
TEMIC TELEFUNKEN microelectronic GmbH semiconductor division has been able to use its policy of
continuous improvements to eliminate the use of ODSs listed in the following documents.
1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively
2 . Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental
Protection Agency ( EPA) in the USA
3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C ( transitional substances ) respectively.
TEMIC can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain
such substances.
We reserve the right to make changes to improve technical design and may do so without further notice.
Parameters can vary in different applications. All operating parameters must be validated for each customer
application by the customer. Should the buyer use TEMIC products for any unintended or unauthorized
application, the buyer shall indemnify TEMIC against all claims, costs, damages, and expenses, arising out of,
directly or indirectly, any claim of personal damage, injury or death associated with such unintended or
unauthorized use.
TEMIC TELEFUNKEN microelectronic GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany
Telephone: 49 ( 0 ) 7131 67 2831, Fax number: 49 ( 0 ) 7131 67 2423
16 (16)
Preliminary Information
TELEFUNKEN Semiconductors
Rev. A1, 28-Jan-97