Preliminary Information
Pin Description (Continued)
Pin #
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
MH88631
Description
Name
XB
VEE
VDD
RXOUT
VCC+
GSR
TXIN-
VCC-
TXIN+
AGND
VR
VX
RGND
GSX
RC1
NETBAL
RD1
CD
RD2
RC2
External relay contact (K1) connection from XC (Pin 8), activated by loop seize control input
(RC1).
Negative Power Supply.
(-5V).
Positive Power Supply.
(+5V)
Audio receive signal (output) tothe RXIN- (Pin 13), via an external decoupling capacitor
(C3).
Positive analog Power Supply Voltage.
(+12V).
Gain Setting Receive (Input).
Normally used to set the receive gain with an external
resistor connected to RXOUT (Pin 24).
Transmit (Input).
Differential audio signal from VTR- (Pin 6), via an external capacitor
(C4).
Negative Analog Power Supply Voltage.
(-12V).
Transmit (Input).
Differential audio signal from VTR- (Pin 6), via an external decoupling
capacitor (C1).
Analog Ground.
Audio Receive (Input).
The four-wire audio signal input to the interface.
Audio Transmit (Output).
The four-wire audio signal output from the interface.
Relay Ground.
Gain Setting Transmit (Input).
Normally used to set the transmit gain with an external
resistor connected to VX (Pin 32).
Relay Control 1 (Input).
A logic high will activate the relay (K1) to provide loop seize
across Tip and Ring.
Network Balance (Input).
When there is no connection (open), the network is balanced at
600Ω. When the pin is grounded, the network is balanced at AT&T compromise.
Relay Driver 1 (Output).
Open collector sinks current when RC1 is high. Diode clamp
protected.
Clamping Diode.
Normally connects to the positive supply voltage.
Relay Driver 2 (Output).
Open collector sinks current when RC2 is high. Diode clamp
protected.
Relay Driver 2 (Input).
A logic high will activate the relay (K2) to provide proper biasing to
the Tip and Ring. This input control is used for Ground Start Trunk only.
39
40
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MITEL [ MITEL NETWORKS CORPORATION ]
