Single/multistandard VIF/SIF-PLL
and FM-PLL/AM demodulators
Preliminary specification
File under Integrated Circuits, IC02
1997 May 12
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
FM-PLL/AM demodulators
FEATURES
• 5 V supply voltage
• Applicable for IFs (Intermediate Frequencies) of
38.9 MHz, 45.75 MHz and 58.75 MHz
• Gain controlled wide band Video IF (VIF)-amplifier
(AC-coupled)
• True synchronous demodulation with active carrier
regeneration (very linear demodulation, good
intermodulation figures, reduced harmonics,
excellent pulse response)
• Robustness for over-modulation better than 105% due
to gated phase detector at L/L accent standard and
PLL-bandwidth control at negative modulated standards
• VCO (Voltage Controlled Oscillator) frequency
switchable between L and L accent (alignment external)
picture carrier frequency
• VIF AGC (Automatic Gain Control) detector for gain
control, operating as peak sync detector for B/G, peak
white detector for L; signal controlled reaction time for L
• Tuner AGC with adjustable TakeOver Point (TOP)
• AFC (Automatic Frequency Control) detector without
extra reference circuit
TDA9817; TDA9818
• AC-coupled limiter amplifier for sound intercarrier signal
• Alignment-free FM PLL (Phase Locked Loop)
demodulator with high linearity
• SIF (Sound IF) input for single reference QSS (Quasi
Split Sound) mode (PLL controlled); SIF AGC detector
for gain controlled SIF amplifier; single reference QSS
mixer able to operate in high performance single
reference QSS mode and in intercarrier mode
• AM demodulator without extra reference circuit
• Stabilizer circuit for ripple rejection and to achieve
constant output signals
• ESD (Electrostatic Discharge) protection for all pins.
GENERAL DESCRIPTION
The TDA9817 is an integrated circuit for single standard
vision IF signal processing and FM demodulation.
The TDA9818 is an integrated circuit for multistandard
vision IF signal processing, sound AM and FM
demodulation.
supply voltage4.555.5V
supply current7690104mA
vision IF input signal voltage
−1 dB video at output−60100µV
sensitivity (RMS value)
video output signal voltage
0.971.11.23V
(peak-to-peak value)
−3 dB video bandwidth on pin 16B/G and L standard;
< 20 pF; RL>1kΩ; AC load
C
L
weighted signal-to-noise ratio for
78−MHz
5660−dB
video
intermodulation attenuation at ‘blue’f = 1.1 MHz5864−dB
intermodulation attenuation at ‘blue’f = 3.3 MHz5864−dB
suppression of harmonics in video
3540−dB
signal
sound IF input signal voltage
−3 dB at intercarrier output−50100µV
sensitivity (RMS value)
audio output signal voltage for FM
(RMS value)
B/G standard;
27 kHz modulation (54%)
M, N standard;
0.40.50.6V
0.360.450.54V
25 kHz modulation
audio output signal voltage for AM
L standard; 54% modulation0.40.50.6V
(RMS value)
total harmonic distortion audio signal54% modulation
FM−0.20.5%
AM−0.51.0%
weighted signal-to-noise ratio audio
54% modulation
signal
FM5560−dB
AM4753−dB
1997 May 123
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
FM-PLL/AM demodulators
BLOCK DIAGRAM
video
SOUND
video
16
2021171819
GND
P
V
AFC
VOLTAGE
REFERENCE
AFC
VIDEO
DETECTOR
(p-p)
audio
1 V
TRAP
(p-p)
1.1 V
8
AND AMPLIFIER
DEMODULATOR
1011
9
FM-PLL
DEMODULATOR
13
TDA9817; TDA9818
MHA663
DEC
C
de-em
C
mute
switch
pc
2 × f
and adjust
L/L accent switch
PLL
T
VAGC
C
BL
C
TOP
(1)
615
422
(1)
7
VIF
AGC
AGC
TUNER
14
tuner AGC
VCO
TWD
QSS MIXER
AM DEMODULATOR
INTERCARRIER MIXER
TDA9817
TDA9818
MODE SWITCH
INTERCARRIER
VIF AMPLIFIERFPLL
2
1
VIF
SAW
SIF AMPLIFIER
24
23
SIF
SAW
SIF
mode
intercarrier
AGC
5.5 MHz
12
handbook, full pagewidth
Fig.1 Block diagram.
(1)
3
switch
selection
standards
5
SAGC
C
(1) Not connected for TDA9817.
1997 May 124
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
FM-PLL/AM demodulators
PINNING
SYMBOLPINDESCRIPTION
V
i VIF1
V
i VIF2
(1)
STD
C
VAGC
C
SAGC
T
PLL
(1)
LADJ
V
oAF
V
de-em
C
de-em
C
DEC
V
o QSS
V
iFM
TAGC14tuner AGC output
(1)
C
BL
V
o(vid)
AFC17AFC output
VCO118VCO1 resonance circuit
VCO219VCO2 resonance circuit
GND20ground
V
P
TADJ22tuner AGC takeover point adjust
V
i SIF1
V
i SIF2
1VIF differential input signal voltage 1
2VIF differential input signal voltage 2
3standard switch
4VIF AGC capacitor
5SIF AGC capacitor
6PLL loop filter
7L/L accent switch and adjust
8audio output
15black level detector
16composite video output voltage
21supply voltage
23SIF differential input signal voltage 1
24SIF differential input signal voltage 2
handbook, halfpage
(1) Not connected for TDA9817.
V
V
C
C
LADJ
V
C
V
i VIF1
i VIF2
STD
VAGC
SAGC
T
PLL
V
o AF
de-em
de-em
C
DEC
o QSS
1
2
(1)
3
4
5
6
(1)
7
8
9
10
11
12
Fig.2 Pin configuration.
TDA9817; TDA9818
V
24
i SIF2
V
23
i SIF1
TADJ
22
V
21
P
GND
20
VCO2
MHA664
19
VCO1
18
AFC
17
V
16
o(vid)
(1)
C
15
BL
TAGC
14
13
V
i FM
TDA9818
TDA9817
Note
1. Not connected for TDA9817.
1997 May 125
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
FM-PLL/AM demodulators
FUNCTIONAL DESCRIPTION
The integrated circuit comprises the functional blocks as
shown in Fig.1:
• Vision IF amplifier and VIF AGC detector
• Tuner AGC
• Frequency Phase Locked Loop detector (FPLL)
• VCO, Travelling Wave Divider (TWD) and AFC
• Video demodulator and amplifier
• SIF amplifier and SIF AGC
• Single reference QSS mixer
• AM demodulator
• FM-PLL demodulator
• AF (Audio Frequency) signal processing
• Internal voltage stabilizer.
Vision IF amplifier and VIF AGC detector
The vision IF amplifier consists of three AC-coupled
differential amplifier stages. Each differential stage
comprises a feedback network controlled by emitter
degeneration.
The AGC detector generates the required VIF gain control
voltage for constant video output by charging/discharging
the AGC capacitor. Therefore for negative video
modulation the sync level and for positive video
modulation the peak white level of the video signal is
detected. In order to reduce the reaction time for positive
modulation, where a very large time constant is needed,
an additional level detector increases the discharging
current of the AGC capacitor (fast mode) in the event of a
decreasing VIF amplitude step. The additional level
information is given by the black-level detector voltage.
Tuner AGC
The AGC capacitor voltage is converted to an internal IF
control signal, and is fed to the tuner AGC to generate the
tuner AGC output current at pin TAGC (open-collector
output). The tuner AGC takeover point can be adjusted at
pin TADJ. This allows to match the tuner to the SAW filter
in order to achieve the optimum IF input level.
Frequency Phase Locked Loop detector (FPLL)
The VIF-amplifier output signal is fed into a frequency
detector and into a phase detector via a limiting amplifier.
During acquisition the frequency detector produces a DC
current proportional to the frequency difference between
the input and the VCO signal. After frequency lock-in the
phase detector produces a DC current proportional to the
TDA9817; TDA9818
phase difference between the VCO and the input signal.
The DC current of either frequency detector or phase
detector is converted into a DC voltage via the loop filter,
which controls the VCO frequency. In the event of positive
modulated signals the phase detector is gated by
composite sync in order to avoid signal distortion for
overmodulated VIF signals.
VCO, Travelling Wave Divider (TWD) and AFC
The VCO operates with a resonance circuit (with L and C
in parallel) at double the PC frequency. The VCO is
controlled by two integrated variable capacitors.
The control voltage required to tune the VCO from its
free-running frequency to actually double the PC
frequency is generated by the frequency-phase detector
(FPLL) and fed via the loop filter to the first variable
capacitor. This control voltage is amplified and additionally
converted into a current which represents the AFC output
signal. At centre frequency the AFC output current is equal
to zero.
For TDA9818: the VCO centre frequency can be
decreased (required for L accent standard) by activating
an additional internal capacitor. This is achieved by using
the L accent switch. In this event the second variable
capacitor can be controlled by a variable resistor at the L
accent switch for setting the VCO centre frequency to the
required L accent value.
The oscillator signal is divided by 2 with a TWD which
generates two differential output signals with a 90 degree
phase difference independent of the frequency.
Video demodulator and amplifier
The video demodulator is realized by a multiplier which is
designed for low distortion and large bandwidth. The vision
IF input signal is multiplied with the ‘in phase’ signal of the
travelling wave divider output. In the demodulator stage
the video signal polarity can be switched in accordance
with the TV standard.
The demodulator output signal is fed via an integrated
low-pass filter for attenuation of the carrier harmonics to
the video amplifier. The video amplifier is realized by an
operational amplifier with internal feedback and high
bandwidth. A low-pass filter is integrated to achieve an
attenuation of the carrier harmonics for B/G and
L standard. The standard dependent level shift in this
stage delivers the same sync level for positive and
negative modulation. The video output signal at V
1.1 V (p-p) for nominal vision IF modulation, in order to
achieve 1 V (p-p) at sound trap output.
o(vid)
is
1997 May 126
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
FM-PLL/AM demodulators
SIF amplifier and SIF AGC
The sound IF amplifier consists of two AC-coupled
differential amplifier stages. Each differential stage
comprises a controlled feedback network provided by
emitter degeneration.
The SIF AGC detector is related to the SIF input signal
(average level of AM or FM carrier) and controls the SIF
amplifier to provide a constant SIF signal to the
AM demodulator and single reference QSS mixer.
At L standard (AM sound) the SIF AGC reaction time is set
to ‘slow’ for nominal video conditions. But with a
decreasing VIF amplitude step the SIF AGC is set to ‘fast’
mode controlled by the VIF AGC detector. In FM mode this
reaction time is always ‘fast’.
Single reference QSS mixer
The single reference QSS mixer is realized by a multiplier.
The SIF amplifier output signal is fed to the single
reference QSS mixer and converted to intercarrier
frequency by the regenerated picture carrier (VCO).
The mixer output signal is fed via a high-pass for
attenuation of the video signal components to the output
pin 12. With this system a high performance hi-fi stereo
sound processing can be achieved.
For a simplified application without a sound IF SAW filter
the single reference QSS mixer can be switched to the
intercarrier mode by connecting pin 24 to ground. In this
mode the sound IF passes the vision IF SAW filter and the
composite IF signal is fed to the single reference QSS
mixer. This IF signal is multiplied with the 90 degree TWD
output signal for converting the sound IF to intercarrier
frequency. This composite intercarrier signal is fed to the
output pin 12, too. By using this quadrature detection, the
low frequency video signals are removed.
AM demodulator
The AM demodulator is realized by a multiplier.
The modulated SIF amplifier output signal is multiplied in
phase with the limited (AM is removed) SIF amplifier
output signal. The demodulator output signal is fed via an
integrated low-pass filter for attenuation of the carrier
harmonics to the AF amplifier.
TDA9817; TDA9818
consists of 7 stages which are internally AC-coupled in
order to minimize the DC offset.
Furthermore the AF output signal can be muted by
connecting a resistor between the limiter input pin 13 and
ground.
The FM-PLL consists of an integrated relaxation oscillator,
an integrated loop filter and a phase detector.
The oscillator is locked to the FM intercarrier signal, output
from the limiter. As a result of locking, the oscillator
frequency tracks with the modulation of the input signal
and the oscillator control voltage is superimposed by the
AF voltage. The FM-PLL operates as an FM demodulator.
AF signal processing
The AF amplifier consists of two parts:
1. The AF pre-amplifier for FM sound is an operational
amplifier with internal feedback, high gain and high
common mode rejection. The AF voltage from the
PLL demodulator, by principle a small output signal, is
amplified by approximately 33 dB. The low-pass
characteristic of the amplifier reduces the harmonics of
the intercarrier signal at the sound output terminal
pin 9 at which the de-emphasis network for FM sound
is applied. An additional DC control circuit is
implemented to keep the DC level constant,
independent of process spread.
2. The AF output amplifier (10 dB) provides the required
output level by a rail-to-rail output stage. This amplifier
makes use of an input selector for switching to AM, FM
de-emphasis or mute state, controlled by the standard
switching voltage and the mute switching voltage.
Internal voltage stabilizer
The bandgap circuit internally generates a voltage of
approximately 1.25 V, independent of supply voltage and
temperature. A voltage regulator circuit, connected to this
voltage, produces a constant voltage of 3.6 V which is
used as an internal reference voltage.
FM-PLL demodulator
The FM-PLL demodulator consists of a limiter and an
FM-PLL. The limiter provides the amplification and
limitation of the FM sound intercarrier signal. The result is
high sensitivity and AM suppression. The amplifier
1997 May 127
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
TDA9817; TDA9818
FM-PLL/AM demodulators
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
SYMBOLPARAMETERCONDITIONSMIN.MAX.UNIT
V
P
V
i
t
sc(max)
V
TAGC
T
stg
T
amb
V
es
Notes
1. I
P
2. Machine model class B.
supply voltagemaximum chip temperature
−5.5V
of 110 °C; note 1
voltage at pins 1 to 6, 9 to 11, 13to15, 17
0V
and 21 to 24
maximum short-circuit time to ground or V
P
−10s
tuner automatic gain control output voltage013.2V
storage temperature−25+150°C
operating ambient temperature−20+70°C
electrostatic handling voltagenote 2−300+300V
= 104 mA; T
=70°C; R
amb
th j-a
= 65 K/W.
P
V
THERMAL CHARACTERISTICS
SYMBOLPARAMETERCONDITIONSVALUEUNIT
R
th j-a
thermal resistance from junction to ambient in free air65K/W
1997 May 128
Philips SemiconductorsPreliminary specification
Single/multistandard VIF/SIF-PLL and
TDA9817; TDA9818
FM-PLL/AM demodulators
CHARACTERISTICS
V
=5V; T
P
peak white level for L); IF input from 50 Ω via broadband transformer 1 : 1; video modulation DSB; residual carrier
B/G: 10%; L = 3%; video signal in accordance with
Fig.13; unless otherwise specified.
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
Supply (pin 21)
V
P
I
P
Vision IF amplifier (pins 1 and 2)
V
i(VIF)(rms)
V
i(max)(rms)
∆V
o(int)
G
IF(cr)
R
i(diff)
C
i(diff)
V
I(1,2)
True synchronous video demodulator; note 3
f
VCO(max)
∆f
/∆Toscillator drift as a function
osc
∆f
/∆V
osc
V
VCO(rms)
f
cr(pc)
∆f
pc(fr)
f
alg(L accent)
t
acq
=25°C; see Table 1 for input frequencies and level; input level V