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參數(shù)資料
| 型號： | HC55171BIM |
| 廠商： | INTERSIL CORP |
| 元件分類： | 模擬傳輸電路 |
| 英文描述： | Low Cost 5 REN Ringing SLIC for ISDN Modem/TA and WL |
| 中文描述： | TELECOM-SLIC, PQCC28 |
| 封裝： | PLASTIC, LCC-28 |
| 文件頁數(shù)： | 7/11頁 |
| 文件大?。?/td> | 87K |
| 代理商： | HC55171BIM |
69
The voltages listed in the tables are driven from a logic
source that will not drive the ringing input negative. If the
ringing input is driven negative by 200mV, the peak-to-peak
ringing amplitudes can be increased.
Ringing Voltage Limiting Factors
As the load impedance decreases (increasing REN), the
source impedance of the SLIC during ringing slightly
attenuates the ringing signal.
If additional surge protection resistance must be used with
the trapezoidal circuit, the loop length performance of the
circuit will decrease proportionally to the added resistance
in the Tip and Ring leads. For example if 30
protection
resistors is used in each of the Tip and Ring leads, the
ringing loop length will decrease by a total of 60
.
Low Level Ringing Interface
The trapezoidal application circuit only requires a cadenced
logic signal applied to the wave shaping RC network to
achieve ringing. When not ringing, the logic signal should be
held low. When the logic signal is low, Tip will be near
ground and Ring will be near battery. When the logic signal
is high, Tip will be near battery and Ring will be near ground.
Loop Detector Interface
The RTD output should be monitored for off hook detection
during the ringing period. At all other times, the SHD should
be monitored for off hook detection. The application circuit
can be modified to redirect the ring trip information through
the SHD interface. The change can be made by rewiring the
application circuit, adding a pullup resistor to pin 23 and set-
ting F0 low for the entire duration of the ringing period. The
modifications to the application circuit for the single detector
interface are shown in Figure 1.
SLIC Operating State During Ringing
The SLIC control pin F1 should always be a logic high during
ringing. The control pin F0 will either be a constant logic high
(two detector interface) or a logic low (single detector
interface). Figure 2 shows the control interface for the dual
detector interface and the single detector interface.
Additional Application Information
Transhybrid Balance
Since the receive signal and its echo are 180 degrees out of
phase, the summing node of an operational amplifier can be
used to cancel the echo. Nearly all CODECs have an inter-
nal amplifier for echo cancellation. The circuit in Figure 3
shows the cancellation amplifier circuit.
TABLE 3. CREST FACTOR PROGRAMMING RESISTOR FOR
V
BAT
= -65V
R
TRAP
CF
RMS
R
TRAP
CF
RMS
0
1.10
52.5
1330
1.25
45.9
660
1.15
49.8
1600
1.30
44.1
1040
1.20
47.8
1800
1.35
42.5
TABLE 4. CREST FACTOR PROGRAMMING RESISTOR FOR
V
BAT
= -60V
R
TRAP
CF
RMS
R
TRAP
CF
RMS
0
1.10
48.2
1460
1.25
42.0
740
1.15
45.6
1760
1.30
40.4
1129
1.20
43.7
2030
1.35
38.8
HC55171B
V
RING
24
C
TRAP
V
RING
R
TRAP
D
TRAP
RDO 21
RDI 20
NU 23
ADDITIONAL PULL UP RESISTOR
V
CC
FIGURE 1. APPLICATION CIRCUIT WIRING FOR SINGLE
LOOP DETECTOR INTERFACE
FIGURE 2. DETECTOR LOGIC INTERFACES
F1
RINGING
ACTIVE
ACTIVE
F0
V
RING
MODE
(LOGIC HI)
(LOGIC HI)
RTD
SHD
SHD
VALID DET
F1
RINGING
ACTIVE
ACTIVE
F0
V
RING
MODE
(LOGIC HI)
(LOGIC HI)
SHD
SHD
SHD
VALID DET
(SINGLE DETECTOR INTERFACE)
(DUAL DETECTOR INTERFACE)
FIGURE 3. TRANSHYBRID AMPLIFIER CIRCUIT
+
-
R
F
R
B
R
A
V
RX
V
OUT1
VO
HC55171B
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| HC55171IB | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC55171 | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC55171CB | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC55171CM | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
| HC55171IM | 5 REN Ringing SLIC for ISDN Modem/TA and WLL |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| HC55171CB | 制造商:Rochester Electronics LLC 功能描述:- Bulk |
| 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 |
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