MH88631
LPGND
VDD
RINGND
T
R
VTR-
VTR+
XC
XA
QE
AGND
RXIN+
RXIN-
VEE
TG
RC
RV
FC
RG
QB
Preliminary Information
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
XB
VEE
VDD
RXOUT
VCC+
GSR
TXIN-
VCC-
TXIN+
AGND
VR
VX
RGND
GSX
RC1
NETBAL
RD1
CD
RD2
RC2
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
Figure 2 - Pin Connections
Pin Description
Pin #
1
2
3
Name
LPGND
VDD
RINGND
Description
Loop Ground
is the system ground reference with respect to -48V.
Positive Power Supply
(+5V).
Ring Ground (Input).
For Ground Start Trunk only a logic low input will enable the trunk
circuit to ground the Ring lead through a low resistance (390Ω). This is a signal to the C.O.
that the interface is seizing the line.
Tip (Input).
Normally connects to the “Tip” lead of the C.O.
Ring (Input).
Normally connects to the “Ring” lead of the C.O.
Connects to the TXIN+ (Pin 29) via an external capacitor (C1).
Connects to the collector of an external transistor (Q1) and TXIN- (Pin 27) via an external
capacitor (C4)
External relay contact (K1) connection from XB (Pin 21), activates by loop seize control
input (RC1).
External relay contact (K1) connection from VTR+ (Pin 7), activated by loop seize control
input (RC1).
Connects to the emitter of an external transistor (Q1).
Analog Ground.
Differential Receive (Input).
Connects to analog ground via an external capacitor (C2).
Differential Receive (Input).
Connects to RXOUT (Pin 24) via an external capacitor (C3).
Negative Power Supply.
(-5V).
Tip Lead Ground Detect (Output).
Active low.
Reverse Loop Current Detect (Output).
Active low.
Ringing Voltage Detect (Output).
Active low.
Forward Loop Current Detect (Output).
Active low
Ring Lead detect (Output).
Active low.
Connects to the base of an external transistor (Q1).
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
2-226
T
R
VTR-
VTR+
XC
XA
QE
AGND
RXIN+
RXIN-
VEE
TG
RC
RV
FC
RG
QB
MITEL [ MITEL NETWORKS CORPORATION ]
