4-29
HC55142
(28 LEAD SOIC)
TOP VIEW
HC55150
(28 LEAD SOIC)
TOP VIEW
Pinouts - 28 Lead SOIC Packages
(Continued)
ZT
PTG
RRLY
CH
RING
BGND
TIP
VBH
VBL
RDC_RAC
CDC
DT
DR
CRT_REV_LVM
AGND
SPM
VRX
RSYNC_REV
ILIM
RD
SHD
C1
C2
C3
GKD_LVM
VTX
ROH
V
CC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
ZT
PTG
RRLY
CH
RING
BGND
TIP
VBH
VBL
RDC_RAC
CDC
DT
DR
CRT_REV_LVM
AGND
SPM
VRX
RSYNC_REV
ILIM
RD
SHD
C1
C2
C3
LVM
VTX
ROH
V
CC
28
27
26
25
24
23
22
21
20
19
18
17
16
15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin Descriptions
28
PIN
PLCC
32
PIN
PLCC
28
PIN
SOIC
SYMBOL
DESCRIPTION
1
1
2
PTG
Programmable Transmit Gain - The 2-wire to 4-wire transmission gain is 0dB if this pin is left floating
and -6.02dB if tied to ground. The -6.02dB gain option is useful in systems where Pulse Metering is
used. See Figure 23.
2
2
3
RRLY
Ring Relay Driver Output - The relay coil may be connected to a maximum of 14V.
3
3
4
CH
AC/DC Separation Capacitor - CH is required to properly process the AC current from the DC loop
current. Recommended value 0.1
μ
F.
4
4
1
ZT
2-Wire Impedance Matching Pin - Impedance matching of the 2-wire side is accomplished by placing
an impedance between the ZT pin and ground. See Equation 32.
5
5
5
RING
Connects via protection resistor R
P
to ring wire of subscriber pair.
6
6
6
BGND
Battery ground.
7
7
7
TIP
Connects via protection resistor R
P
to tip wire of subscriber pair.
8
8
8
V
BH
High Battery Supply (negative with respect to GND).
9
9
9
V
BL
Low Battery Supply (negative with respect to GND, magnitude
≤
V
BH
).
10
10
10
RDC_RAC
Resistive Feed/Anti Clipping - Performs anti clipping function on constant current application and sets
the slope of the resistive feed curve for constant voltage applications.
11
11
14
CRT_REV
_LVM
Ring Trip, Soft Polarity Reversal and Line Voltage Measurement - A capacitor when placed between the
CRT_REV_LVM pin and +5V performs 3 mutually exclusive functions. When the SLIC is configured in the
Ringingmodeitprovidesfilteringoftheringingsignaltopreventfalsedetect.WhentheSLICistransitioning
betweentheForwardActiveStateandReverseActiveStateitprovidesSoftPolarityReversalandperforms
charge storage in the Line Voltage Measurement State. Recommended value 0.47
μ
F.
12
12
11
CDC
Filter Capacitor- The CDC Capacitor removes the VF signals from the battery feed control loop.
13
13
12
DT
Tip side of Ring Trip Detector - Ring trip detection is accomplished by connecting an external network
to a detector in the SLIC with inputs DT and DR. Ring trip occurs when the voltage on DT is more
negative than the voltage on DR.
14
14
13
DR
Ring Side of Ring Trip Detector - Ring trip detection is accomplished by connecting an external
network to a detector in the SLIC with inputs DT and DR. Ring trip occurs when the voltage on DR is
more positive than the voltage on DT.
-
15
-
C5
Activates Test Relay TRLY2.
HC55120, HC55121, HC55130, HC55131, HC55140, HC55141, HC55142, HC55143, HC55150, HC55151