N681622YG Nuvoton Technology Corporation of America, N681622YG Datasheet - Page 27

• Manufacturer Part Number: N681622YG
• Manufacturer: Nuvoton Technology Corporation of America

Specifications of N681622YG

• Lead Free Status / RoHS Status: Supplier Unconfirmed

The control circuit for TIP or RING is illustrated in Figure 5 and utilizes a three transistor discrete Linefeed circuit.
Transistors Q1 and Q2 drive the voltages on the subscriber loop while transistor Q3 provides additional isolation.
The Line Driver DC feedback loop is completed via DC isolation resistors R
signals are derived from the common mode and differential mode signal block. This information is, in turn, used to
exercise control over the external transistors. Voice band signals are passed over a decoupling capacitor in the AC
feedback loop.
Control and monitoring of these transistors is done both individually and in groups. For example, TIP and RING
Linefeed circuits each have a Q1 transistor. Both share the same register to set their Power Alarm Threshold values.
But each TIP and RING transistor has a separate Power Alarm Interrupt bit in the interrupt register.
The control circuit for TIP and RING whenN681622 is utilized follows the same general principles.
Preliminary Datasheet Rev1.0
TIP or RING
TIP or RING
VBAT
VBAT
Differential Mode
Differential Mode
Common Mode
Common Mode
Signals
Signals
R
VBAT
R
R
QE
QE
Linefeed
Linefeed
Discrete
Discrete
R
R
VE
VE
Q3
Q3
R
R
B3
B3
Q2
Q2
Q1
Q1
I
I
VDD
VDD
OUT
OUT
Figure 6: Line Loop Control
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OTA
On- chip
On- chip
OTA
Mux
Mux
+
+
+
-
-
-
+
+
Single Programmable Extended Codec/SLCC
+
+
VBAT
and R
Sigma/Delta
Sigma/Delta
LineFeed
LineFeed
DAC
ADC
DAC
ADC
VE
to the chip. TIP and RING
N681386/87
LLC-v1
LLC-v1
January 2010
AC Loop
AC Loop
DC Loop
DC Loop