MT8931C
Microprocessor
Termination
Network
RTx
2:1
LTx
Lout+
Lin+
C4b
F0b
C4b
F0b
‡
VDD
R
MT8931C
NT Mode
10µF
MT8910-1
DSLIC
MH89101
VBias
Lin-
‡
DSTo
DSTi
DSTi
R
Lout-
DSTo
LRx
2:1
+5V
Power Supply
and
Power Feed
S Reference
Point
U Reference
Point
‡
100Ω terminating resistor
Figure 17 - NT1 using the MT8910-1 (DSLIC) and MT8931C (SNIC)
MT9094
MT8931C
DSTo
DSTi
HSPKR+
RTx
DSTo
DSTi
HSPKR-
M+
1:2
Handset
VDD
‡
F0b
C4b
R
F0i
C4i
LTx
M-
VBias
‡
MIC+
MIC-
R
LRx
Microphone
Speaker
XTAL1
XTAL2
1:2
SPKR+
2kΩ
SPKR-
Data Port
IRQ
S12-1
Display
DATA1
CS
SCLK
+5V
1
4
7
2
5
8
0
3
6
9
#
DC to DC
Converter
K
e
y
p
a
d
+5V
8051
10k
IRQ
‡
100Ω terminating resistor
*
Figure 18 - ISDN Digital Telephone Set
9-96