2-175
Preliminary Information
MH88622
17
NC
No Connection.
This pin should not be connected.
18
NC
No Connection
. This pin should not be connected.
19
RF1
Ringing Frequency Node 1 (Input)
. A capacitor is connected between RF1 & RF2 and
determines the frequency of the ringing generator.
20
RF2
Ringing Frequency Node 2 (Input).
Two capacitors are connected between RF1& RF2
and from RF2 to AGND. This determines the frequency of the ringing generator.
21
RGV
Ringing Gain Voltage.
Connects to RG1 through a resistor to reduce the output ringing
voltage. When left open circuit output ringing voltage is 90Vrms.
22
RG1
Ringing Gain Node 1.
Connects to RGV through a resistor to reduce the output ringing
voltage. When left open circuit output ringing voltage is 90Vrms.
23
NC
No Connection.
This pin should not be connected.
24
NC
No Connection.
This pin should not be connected.
25
RC2
Ringing Control (Input).
A logic level applied to this pin enables ringing to be applied
across Tip and Ring of subscriber 2.
26
LR2
Line Reversal.
A logic 1 applied to LR2 will reverse the “Tip” and “Ring” to subscriber 2.
This pin has an internal pull down
.
27
VDD
Positive Supply Voltage.
+5Vdc. This pin should be connected to pin 14 of the hybrid on
the PCB.
28
GND
Ground.
Return path for VDD, VEE, VBat & DCRI. This pin should be connected to pins 5,
13 & 36 of the hybrid on the pcb.
29
VEE
Negative Supply Voltage
.
-5Vdc. This pin should be connected to pin 12 of the hybrid on
the PCB.
30
VX2
Transmit (Output)
. 4-Wire GND referenced audio input for subscriber 2.
31
LCS2
Loop Current Set 2.
Logic 1 gives ILoop = 40mA, Logic 0 gives ILoop = 25mA.
32
SHK2
Off Hook Indication (Output).
A logic high output indicates when subscriber 2 equipment
has gone off hook.
33
VR2
Receive (Input).
4-Wire GND referenced audio input for subscriber 2.
34
ESE2
External Signal Enable (Input).
The external signal to subscriber 2 is controlled by a logic
level applied to this pin.
35
ESI2
External Signal Input.
A continuous signal should be applied to this pin which will be
switched to “Tip” and “Ring” of subscriber 2.
36
GND
Ground.
This pin should be tied to pins 5, 13 & 28 on the PCB.
37
DCRI
DC Ringing Voltage Input.
A continuous 120Vdc is applied to this input to achieve 90
Vrms ringing. This should be connected to pin 4 of the hybrid on the PCB.
38
VBAT
Battery Voltage.
Typically -48V dc is applied to this pin. This should be connected to pin 3
of the hybrid on the PCB
.
39
RING2
Ring Lead.
Connects to the “Ring” lead of subscriber line 2.
40
TIP2
Tip Lead.
Connects to the “Tip” lead of subscriber line 2.
Pin Description (Continued)
Pin #
Name
Description