STV0056A
PIN INTERNAL CIRCUITRY (continued)
VID IN
Figure 7
VREF 2.4V
10kΩ
VID IN
6.5kΩ
+
0.5pF
GND 0V
1
85µA
PK OUT R, PK OUT L
Figure 8
Audio
VDD 9V
1
3.4V
Peak Detector
1 5kΩ
Clamp
PK OUT R
PK OUT L
FC L, FC R
Ivar is controlled by the peak det audio level max.
±15µA (1VPP audio).
Figure 9
VDD 9V
FC L
FC R
Ivar
1
1
VOL OUT R, VOL OUT L
Audio output with volume and scart driver with
+12dB of gain for up to 2VRMS. The opamp has a
push-pull output stage.
Figure 10
Audio
2.4V Bias
30kΩ
30kΩ
4.8V
VOL OUT R
VOL OUT L
15kΩ
GND 0V
S2 OUT L, S2 OUT R, S3 OUT L, S3 OUT R
Same as above but with gain fixed at +6dB.
Figure 11
Audio
2.4V Bias
20kΩ
S2 OUT L
S2 OUT R
S3 OUT L
S3 OUT R
20kΩ
GND 0V
S2 RTN L, S2 RTN R, S3 RTN L, S3 RTN R
4.8V bias voltage is the same as the bias level on
the audio outputs.
Figure 12
S2 RTN L
S2 RTN R
S3 RTN L
S3 RTN R
4.8V
25kΩ
1
50µA
FM IN
The other input for each channel is internally biased
in the same way via 10kΩ to the 2.4V VREF.
Figure 13
FM IN
2.4V
10kΩ
10kΩ
Left Channel
1
Right Channel
50µA
1
50µA
IREF
The optimum value if IREF is 50µA ±2% so an
external resistor of 47.5kΩ ±1% is required.
Figure 14
2.4V
1
IREF
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