TDA9899_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 15 January 2008 62 of 103
NXP Semiconductors
TDA9899
Multistandard hybrid IF processing including car mobile
[18] Measured with an FM deviation of 25 kHz and the typical AF output voltage of 500 mV (RMS). The audio signal processing stage
provides headroom of 6 dB with THD < 1.5 %. The I
2
C-bus bits W3[0] and W3[1] control the AF output signal amplitude from
0dBto−18 dB in steps of −6 dB. Reducing the audio gain for handling a frequency deviation of more than 55 kHz avoids AF output
signal clipping.
[19] Amplitude response depends on dimensioning of FM PLL loop filter and components at pin APCLC and pin APCHC.
[20] The lower AF cut-off frequency depends on the value of the capacitor at pin CAF. A value of C
AF
= 470 nF leads to f
−3dB(AF)l
≈ 20 Hz and
C
AF
= 220 nF leads to f
−3dB(AF)l
≈ 40 Hz.
[21] For all signal-to-noise measurements the used VIF modulator has to meet the following specifications:
a) Incidental phase modulation for black-to-white jump less than 0.5 degrees.
b) QSS AF performance, measured with the television demodulator AMF2 (audio output, weighted signal-to-noise ratio) better than
60 dB (at deviation 27 kHz) for 6 kHz sine wave black-to-white video modulation.
c) Picture-to-sound carrier ratio PC / SC1 = 13 dB (transmitter).
[22] The PC / SC ratio is calculated as the addition of TV transmitter PC / SC1 ratio and SAW filter PC / SC1 ratio. This PC / SC ratio is
necessary to achieve the weighted signal-to-noise values as noted. A different PC / SC ratio will change these values.
[23] Measurement condition is SC1 / SC2 ≥ 7dB.
[24] The differential QSS signal output on pins OUT1A and OUT1B is analyzed by a test demodulator TDA9820. The signal-to-noise ratio of
this device is better than 60 dB. The measurement is related to an FM deviation of ±27 kHz and in accordance with
“ITU-R BS.468-4”
.
[25] Sound carrier not present.
[26] The tolerance of the reference frequency determines the accuracy of VIF AFC, RIFAFC, FM demodulator center frequency, maximum
FM deviation, sound trap frequency, LIF band-pass cut-off frequency and ZIF low-pass cut-off frequency as well as the accuracy of the
synthesizer.
[27] The value of C
pull
determines the accuracy of the resonance frequency of the crystal. It depends on the used type of crystal.
[28] The AC characteristics are in accordance with the I
2
C-bus specification for fast mode (maximum clock frequency is 400 kHz).
Information about the I
2
C-bus can be found in the brochure
“The I
2
C-bus and how to use it”
(order number 9398 393 40011).
[29] The SDA and SCL lines will not be pulled down if V
P
is switched off.
[30] The threshold is dependent on V
P
.
[31] The threshold is independent of V
P
.
Table 56. Examples to the FM PLL filter
B
LF(−3dB)
(kHz) C
s
(nF) C
par
(pF) R
s
(kΩ) Comment
210 2.2 100 8.2 recommended for single-carrier-sound,
FM narrow
410 2.2 47 5.6 recommended for single-carrier-sound, FM wide
130 2.2 470 5.6 recommended for two-carrier-sound, FM narrow
210 2.2 47 8.2 used for test circuit
Table 57. Input frequencies and carrier ratios (examples)
Symbol Parameter B/G standard M/N standard L standard L-accent standard Unit
f
PC
picture carrier frequency 38.375 38.375 38.375 33.625 MHz
f
SC1
sound carrier frequency 1 32.825 33.825 31.825 40.125 MHz
f
SC2
sound carrier frequency 2 32.583 - - - MHz
PC / SC1 picture to first sound carrier ratio 13 7 10 10 dB
PC / SC2 picture to second sound carrier ratio 20 - - - dB
