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參數(shù)資料
| 型號(hào)： | HC55171CB |
| 廠商： | INTERSIL CORP |
| 元件分類： | 模擬傳輸電路 |
| 英文描述： | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| 中文描述： | TELECOM-SLIC, PDSO28 |
| 封裝： | SOIC-28 |
| 文件頁(yè)數(shù)： | 11/18頁(yè) |
| 文件大?。?/td> | 153K |
| 代理商： | HC55171CB |
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HC55171 ringing SLIC meets the REN drive requirement, the
crest factor limitations and the minimum RMS ringing voltage.
The foremost requirement is that the ringing source must be
able to drive 5 REN. A REN is a ringer equivalence number
modeled by a 6.93k
resistor in series with a 8
μ
F capacitor
(see Figure 10). The impedance of 1 REN at 20Hz is approx-
imately 7k
. 5 REN is equivalent to five of the networks in
parallel. Figure 10 provides the Bellcore REN models.
The crest factor of the ringing waveform is the ratio of the
peak voltage to the RMS voltage. For reference, the crest
factor of a sinusoid is 1.414 and of a square wave is 1.0.
Bellcore defines the crest factor range from 1.2 to 1.6. A sig-
nal with a crest factor between 1.2 and 1.414 resembles the
trapezoid of Figure 9. A signal with a crest factor between
1.414 and 1.6 resembles a “rounded triangular” wave shape
and is an inefficient waveform for the ringing SLIC.
The third pertinent Bellcore requirement is the that RMS ringing
voltage must be greater than 40V
RMS
at the telephone instru-
ment. The HC5517 is able to deliver 40V
RMS
at the end of
500
loops. The 500
loop drive capability of the HC5517 is
achieved with trapezoidal ringing.
Sinusoidal Ringing
The HC55171 uses the same sinusoidal application circuit
as the HC5517. The only difference being the values of three
components in the ring trip filter. The following table lists the
components and the different values required by each
device. All reference designators refer to the application
circuit published in the HC5517 and HC55171 data sheet.
The sinusoidal circuit published in the HC5517 can be used
as an additional reference circuit for the HC55171. To gener-
ate a sinusoid ringing signal, two conditions must be met on
the ringing (V
RING
) input of the SLIC.
The first condition is that a positive DC voltage, which is directly
related to the battery voltage, must be present at the ringing
input. The DC voltage is used to force the Tip and Ring DC out-
puts to half the battery voltage. Having both the Tip and Ring
amplifiers biased at the same DC voltage during ringing is one
characteristic of balanced ringing. The centering voltage (V
C
)
can be calculated from the following equation.
Substituting values of battery voltage, the centering voltage
is +1.8V for a -80V battery and +1.3V for a -60V battery.
The second condition that must be met for sinusoidal ringing
is a low level ringing signal must be applied to the ringing
input of the SLIC. The AC signal that is present at V
RING
will
be amplified by a gain of 20 through the Tip amplifier and a
then inverted through the ring amplifier, resulting in a differ-
ential gain of 40. The maximum low level amplitude that can
be injected for a given battery voltage can be determined
from the following equation.
The maximum output swing may be increased by driving the
V
RING
negative by 200mV. Equation 31 can then by
rewritten as:
Exceeding the maximum signal calculated from the above
equation will cause the peaks of the sinusoid to clip at
ground and battery. The compression will reduce the crest
factor of the waveform, producing a trapezoidal waveform.
This is just one method, though inefficient, for achieving trap-
ezoidal ringing. The application circuit provided with the
HC55171 has been specifically developed for trapezoidal
ringing and may also be used with the HC5517.
Trapezoidal Ringing
The trapezoidal ringing waveform provides a larger RMS
voltage to the handset. Larger RMS voltages to the handset
provide more power for ringing and also increase the loop
length supported by the ringing SLIC.
The HC55171 trapezoidal ringing application circuit will oper-
ate for loop lengths ranging from 0
to 500
. In addition, one
FIGURE 9. BALANCED RINGING WAVESHAPES
(A) SINUSOID
GROUND
BATTERY
TIP
RING
(B) TRAPEZOID
GROUND
BATTERY
TIP
RING
FIGURE 10. BELLCORE RINGER EQUIVALENCE MODELS
40
μ
F
5 REN
1386
8
μ
F
1 REN
6930
TABLE 1. RING TRIP COMPONENT DIFFERENCES
COMPONENT
HC5517
COMPONENT
HC55171
R
15
R
17
C
10
47k
56.2k
1.0
μ
F
R
RT3
R
RT1
C
RT
51.1k
49.9k
0.47
μ
F
V
C
V
--------------
4
–
20
=
(EQ. 30)
V
RING Max
)
V
BAT
8
–
(
)
20
=
(EQ. 31)
V
RING Max
)
V
BAT
5
–
(
)
20
=
(EQ. 32)
HC55171
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| HC55171CM | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC55171IM | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC55185BIM | VoIP Ringing SLIC Family |
| HC55185CIM | VoIP Ringing SLIC Family |
| HC55183ECM | Extended Reach Ringing SLIC Family |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| HC55171CM | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| HC55171CM96 | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| HC55171IB | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| HC55171IM | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC5517B | 制造商:INTERSIL 制造商全稱:Intersil Corporation 功能描述:Low Cost 3 REN Ringing SLIC for ISDN Modem/TA and WL |
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