Philips CEM5000/00, Service Manual

Page: 39 / 83

TDA7419
8/30
5 DESCRIPTION OF THE AUDIOPROCESSOR
5.1 Input stages
In the basic configuration, one stereo quasi-differential and three (two in case of DSO applications) single
ended stereo inputs are available.
5.1.1 Quasi-differential stereo Input (QD)
The QD input is implemented as a buffered quasi-differential stereo stage with 100k input-impedance at
each input. The attenuation is fixed to -3dB in order to adapt the incoming signal level.
5.1.2 Single-ended stereo input (SE1, SE2, SE3/AC2IN)
The input-impedance at each input is 100k and the attenuation is fixed to -3dB for incoming signals. The
input for SE3 is also configurable as part of the interface for external filters in DSO applications (AC2IN)
Figure 4. Input Stage
GENERAL
e
NO
Output Noise BW=20Hz to 20 kHz all gain =
0dB 12
µ
V
BW=20Hz to 20 kHz Output
muted 6
µ
V
S/N Signal to Noise Ratio all gain = 0dB flat; V
o
=2V
RMS
100 dB
D Distortion V
IN
= 1V
RMS
; all stages 0dB 0.01 %
S
C
Channel Separation left/right 90 dB
Table 6. Electrical Characteristcs (continued)
V
S
= 8.5V; T
amb
= 25°C; R
L
= 10k
Ω
; all gains = 0dB; f = 1kHz; unless otherwise specified
Symbol Parameter Test Condition Min. Typ. Max. Unit
Output Stage
QD
QD_L
QD_R
QD_G
SE3
SE2
SE2_L
SE2_R
QD
SE1
SE2
SE3
Main
Source
Second
Source
In Gain
SE1
SE1_L
SE1_R
AC2IN_L/SE3L
AC2IN_R/SE3R
SE4