STV0056A
PIN INTERNAL CIRCUITRY (continued)
I/O / 22kHz
The input is TTL compatible.
The output is tri-stateable.
Figure 15
HA
Pull-down current for SDIP42.
Input with CMOS levels.
Figure 19
MUX
22kHz
180µ/2µ I/O/22kHz 205Ω
100 µ/2µ
ESD
10µ/2µ
IIC Reg
91µ/2µ
SCL
This is the input to a Schmitt input buffer made with
a CMOS amplifier.
Figure 16
205Ω
SCL
24µ/4µ
ESD
HA
XTL
Figure 20
205Ω
ESD
150µA
25µ/2µ
10µ/2µ
GND 0V
3
460Ω
XTL
750µA
460Ω
3
2
2
5pF
500µA
GND 0V
750µA
SDA
Input same as above.
Output pull down only : relies on external resistor
for pull-up.
Figure 17
SDA 205Ω
ESD
600µ/2µ
GND 0V
24µ/4µ
J17 L, J17 R, U75 L, U75 R
I1 - I2 = 2 x audio / 18kΩ.
eg 1VPP audio : ±55µA.
The are internal switches to match the audio level
of the different standards.
Figure 18
CPUMP L, CPUMP R
An offset on the PLL loop filter will cause an offset
in the two 1µA currents that will prevent the PLL
from drifting-off frequency.
Figure 21
100µA
Dig Synth
CPUMP L
CPUMP R
100µA
1µA
Loop Filter Tracking
1µA
VCO Input
DET L, DET R
I2 - I1 = f (phase error).
Figure 22
J17 L
I1
J17 R
U75 L
U75 R
I2
I2
DET L
DET R
I1
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