1997 May 26
8
Philips Semiconductors
Product specification
Low power PLL FM demodulator for
satellite TV receivers
TDA8012AM
6.
The capture range or lock-in range is defined as the range where the PLL gets in lock. This value depends strongly
on the loop filter characteristics.
Measurements with test signals in accordance with CCIR recommendation 473-3;
FM modulated signal with DBS parameters:
a) 625 lines PAL TV system
b) 16 MHz/V modulator sensitivity
c) 1 V (p-p) video signal
d) No SAW filter is used.
No SAW filter is used at the input:
a) 16 MHz/V modulator sensitivity
b) 4.43 MHz sine wave colour signal (660 mV (p-p))
c) 3.25 MHz sine wave luminance signal (700 mV (p-p))
d) CCIR pre-emphasis
e) Intermodulation distance is defined as the distance between the luminance signal and the intermodulation
products.The video output spectrum is measured on pin 11 (point A of Fig.4) with a high resistance probe.
The de-emphasis figure is obtained from the measured data by calculation.
No SAW filter is used at the input:
a) 16 MHz/V modulator sensitivity
b) Two sound carriers at 7.02 MHz and 7.20 MHz; 4 MHz deviation
c) Intermodulation measurement without pre-emphasis
d) Intermodulation distance is defined as the distance between one of the sound carriers and the intermodulation
products
e) The video output spectrum is measured on pin 11 (point A of Fig.4) with a high resistance probe and a spectrum
analyser.
10. Measurements are made under the following conditions
a) FM modulator video signal
b) Amplitude level: 57 dB
μ
V
c) Frequency: 479.5 MHz
d) Frequency deviation: 16 MHz
e) CCIR pre-emphasis + unified weighting filter
f) C/N > 50 dB
S/N is measured after de-emphasis with a baseband spectrum from 200 kHz to 5 MHz.
7.
8.
9.
11. The AM sensitivity is defined as the ratio of the baseband output signals obtained from either an AM or FM modulated
RF input signal.
20 logV
o(AM)
FM modulated signal: f
c
= 480 MHz, frequency deviation = 25 kHz, modulation frequency = 20 kHz, input
level = 57 dB
μ
V
AM modulated signal: f
c
= 480 MHz, modulation depth = 50%, modulation frequency = 20 kHz, input
level = 57 dB
μ
V.
12. The characteristics of the AGC function are measured in the application circuit of Fig.4. The circuit illustrated in Fig.4
has been designed to set the maximum AGC current to 1 mA. The output of the AGC function is capable of handling
up to 5 mA. The maximum AGC current can be increased to 5 mA by decreasing the value of the resistor connected
between pins 8 and 9.
S
AM
V
=