MT91600
VDD
TD
TF
TIP
RING
VREF
IC
RF
RV
RD
C3A
C3B
C2B
C2A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VEE
GND
RLYD
RLYC
SHK
C1
X2
VR
X3
VX
X1
Z3
Z2
Z1
Preliminary Information
Figure 2 - Pin Connections
Pin Description
Pin #
1
2
3
4
5
6
Name
VDD
TD
TF
TIP
RING
VREF
Positive supply rail, +5V.
Tip Drive (Output).
Controls the Tip transistor.
Tip Feed.
Connects to the Tip transistor and to the TIP lead via the Tip feed resistor.
Tip.
Connects to the TIP lead of the telephone line.
Ring.
Connects to the RING lead of the telephone line.
Reference Voltage (Input).
This pin is used to set the subscribers loop constant
current. Changing the input voltage sets the current to any desired value within the
working limits. VREF is related to VLC.
Internal Connection (Input).
This pin must be connected to GND for normal operation.
Ring Feed.
Connects to the RING lead via the Ring feed resistor.
Ring Voltage and Audio Feed.
Connects directly to the Ring drive transistor and also to
Ring Feed via a relay.
Ring Drive (Output).
Controls the Ring transistor.
A filter capacitor for over-current protection is connected between this pin and GND.
A filter capacitor for over-current protection is connected between this pin and GND.
A capacitor for loop current stability is connected between this pin and C2A.
A capacitor for loop current stability is connected between this pin and C2B.
Line Impedance Node 1.
A resistor of scaled value "k" is connected between Z1 and
Z2. This connection can not be left open circuit.
Line Impedance Node 2.
This is the common connection node between Z1 and Z3.
Line Impedance Node 3.
A network either resistive or complex of scaled value "k" is
connected between Z3 and Z2. This connection can not be left open circuit.
Gain Node 1.
This is the common node between Z3 and VX where resistors are
connected to set the 2W to 4W gain.
Transmit Audio (Output).
This is the 4W analog signal to the SLIC.
Gain Node 3.
This is the common node between VR and the audio input from the
CODEC or switching network where resistors are fitted to sets the 4W to 2W gain
Receive Audio (Input).
This is the 4W analog signal to the SLIC.
Description
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
IC
RF
RV
RD
C3A
C3B
C2B
C2A
Z1
Z2
Z3
X1
VX
X3
VR
2
MITEL [ MITEL NETWORKS CORPORATION ]
