TDA9875 Philips Semiconductors, TDA9875 Datasheet - Page 28

• Manufacturer Part Number: TDA9875
• Description: Digital TV Sound Processor DTVSP
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Notes to the characteristics
1. ADC level adjust = +6 dB, all other level adjusts = 0 dB, if external 3 dB divider is used set output buffer gain to
2. Due to companding, the quantization noise of the NICAM system limits signal-to-noise ratio to 62 dB
3. Definition of nominal levels:
4. If the supply voltage for the TDA9875 is switched off, because of the ESD protection circuitry, all audio input pins are
5. The SCART specification allows a signal level of up to 2 V (RMS). Because of signal handling limitations due to the
1998 Feb 13
Digital TV Sound Processor (DTVSP)
+3 dB, tone control to 0 dB, AVL off and volume control to 0 dB.
(unweighted; RMS value).
The full-scale level for analog audio signals is V
defined at 15 dB (full-scale).
a) Audio input nominal levels:
b) FM/AM path nominal (maximum) levels:
c) NICAM path nominal (maximum) levels:
short-circuited. To avoid a short-circuit at the SCART inputs a 15 k resistor ( 3 dB divider) has to be used.
5 V supply voltage for the TDA9875, there is a need for fixed 3 dB attenuators at the SCART inputs. To achieve
SCART-to-SCART copies with 0 dB gain, there are +3 dB/0 dB amplifiers at the outputs of SCART 1 and SCART 2
and at the line output. The attenuator is realized by an internal resistor that works together with an external series
resistor as a voltage divider. With this voltage divider the maximum SCART input signal level of 2 V (RMS) is scaled
down to 1.4 V (RMS) at the input pin. To avoid clipping, the +3 dB gain must not be used if the SCART input signal
is larger than 1.4 V (RMS).
SCART: 350 mV (at pin); 12 dB (full-scale)
external, mono: 500 mV; 9 dB (full-scale)
system M: 15 kHz deviation; 23.7 dB (full-scale)
system B/G, D/K, I: 27 kHz deviation; 18.6 dB (full-scale)
SAT stereo (maximum): 50 kHz deviation; 13.3 dB (full-scale)
SAT mono (maximum): 85 kHz deviation; 8.7 dB (full-scale)
AM: 54% modulation; full-scale SIF ADC; 20 dB (full-scale)
system B/G: 18.2 dB (full-scale)
system I: 22.8 dB (full-scale)
maximum level: 0.0 dB (full-scale).
FS
= 1.4 V (RMS). The nominal level at the digital crossbar switch is
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Preliminary specification
TDA9875