TDA9550 PHILIPS [NXP Semiconductors], TDA9550 Datasheet - Page 100

• Manufacturer Part Number: TDA9550
• Description: TV signal processor-Teletext decoder with embedded m-Controller
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
19. Calculation of the FM-PLL filter can be done approximately by use of the following equations:
20. Modulation frequency: 1 kHz, f =
21. f = 4.5/5.5 MHz; FM: 70 Hz,
22. This figure is independent of the TV standard and valid for a frequency deviation of 25 kHz at a carrier frequency
23. The deemphasis pin can also be used as additional audio input. In that case the internal (demodulated FM signal)
24. Audio input signal 200 mV
25. Audio input signal 1 V
26. Unweighted RMS value, audio input signal 500 mV
27. Audio attenuator at 20 dB; temperature range 10 to 50 C.
28. In various versions the Automatic Volume Levelling (AVL) function can be activated. The pin to which the external
29. Signal with negative-going sync. Amplitude includes sync pulse amplitude.
30. This parameter is measured at nominal settings of the various controls.
31. Indicated is a signal for a colour bar with 75% saturation (chroma : burst ratio = 2.2 : 1).
2000 Jun 22
TV signal processor-Teletext decoder with
embedded -Controller
BL
These equations are only valid under the conditions that
Definitions:
K
K
R = loop filter resistor
C
C
f
BL
Some examples for these values are given in table 147
of 4.5 MHz or a deviation of 50 kHz at a carrier frequency of 5.5/6.0/6.5 MHz.
must be switched off. This can be realised by means of the SM (sound mute) bit. When the vision IF amplifier is
switched to positive modulation the signal from the FM demodulator is automatically switched off. The external signal
must be switched off when the internal signal is selected.
capacitor has to be connected depends on the IC version. For the 90 types the capacitor is connected to the EW
output pin. For the 110 types a choice can be made between the AVL function and a sub-carrier output / general
purpose switch output. The selection must be made by means of the CMB0 and CMB1 bit in subaddress 22H (see
also table G-1 on page G-9). More details about the sub-carrier output are given in the parameters D.10.
The Automatic Volume Levelling (AVL) circuit stabilises automatically the audio output signal to a certain level which
can be set by means of the volume control. This AVL function prevents big audio output fluctuations due to variation
of the modulation depth of the transmitter. The AVL can be switched on and off via the AVL bit in subaddress 29H.
The AVL is active over an input voltage range (measured at the deemphasis output) of 150 to 1500 mV
control curve is given in Fig.39. The control range of +6 dB to 14 dB is valid for input signals with 50% of the
maximum frequency deviation.
f o
0
0
D
S
P
= damping factor
= natural frequency of PLL
= VCO steepness in rad/V
=
= phase detector steepness A/rad
= series capacitor
= parallel capacitor
=
3dB
3dB
---------------------------------- -
2R K
------ -
2
1
= f
= loop bandwidth for 3dB
0
K
------------- -
(1.55
1
C
0
0
K
K
P
D
D
C
P
2
)
RMS
RMS
and the volume control setting such that no clipping occurs in the audio output.
. Measured with a bandwidth of 15 kHz and the audio attenuator at 6 dB.
50 kHz deviation; AM: 1.0 kHz, 30% modulation.
50 kHz.
RMS
100
, audio attenuator at 6 dB.
1 and C
TDA955X/6X/8X PS/N1 series
S
5C
P
.
Tentative Device Specification
RMS
. The AVL