
EXTERNAL COMPONENT LISTFOR THE L3000S
Component
Involved Parameter or Function
Ref
RH
RP
CDVB
CVB+
CVB-
DS
Value
22.5K
±
2%
30 to100
47
μ
F - 20V
±
20%
0.1
μ
F - 100V
±
20%
0.1
μ
F - 100V
±
20% (note 1)
BAT49X (note 2)
Bias Resistor
Lines Series Resistor
Battery Voltage Rejection
Positive Battery Filter
Negative Battery Filter
Protective Shottky Diode
EXTERNAL COMPONENT LISTFOR THE L3092
CVSS
CVDD
CAC
ZAC
CCOMP
0.1
μ
F - 15V
0.1
μ
F - 15V
47
μ
F - 10V
±
20%
25 x (ZML- 2xRP)
Negative Supply Voltage Filter
Positive Supply Voltage Filter
AC Path Decoupling
2 Wire AC Impedance
AC Loop Compensation
RPC
RDC
RL
ZA
ZB
25 x (2xRP)
2 x (RFS - RP)
63.4K
±
1
%
K x Z
ML
(note 3)
R
P
Insertion Loss Compensation
DC Feeding Resistor (RDC > 200
)
Bias Resistor
SLIC Impedance Balancing Network
Line Impedance Balancing Network
CINT
RT
RR
RS
CS
see Table 2 (note 5)
47K
47K
1.5M
(note 6)
47nF
Ring Trip Detection Time Constant
Resistors used only inthe automatic stand-by mode.
To be used only if high common mode rejection in Aut. SBY
mode and in Power Down mode is requested (note 7)
To be used only if Power on reset requested. The capacitor
value depends on V
DD
rise time.
CMR
100nF
Notes:
1) In case line cards with less than 7 subscribers are implemented CVB- capacitor should be equal to 680nF/N where N is the number of
subscriber per card.
2) This shottky diode or equivalent is necessary to avoid damage to the device during hot insertion or in all those cases when a proper power
up sequence cannot be guaranteed. Incase theShottkydiode is not implementedthe powersequence should guarantee that VB+is always
the last supply applied at poweron and the firstremoved at power off.
In case an other shottky diode type is adopted it must fulfill the following characteristics:
V
F
< 450mV@ I
F
= n
15mA, T
amb
= 25
°
C
V
F
< 350mV@ I
F
= n
15mA, T
amb
= 50
°
C (T
jL3000S
= 90
°
C)
V
< 245mV@ I
= n
15mA, T
= 85
°
C (T
= 120
°
C)
Where n is the number of line sharing the same diode.
3) The structure of this networkshall copy the SLIC output impedance multiplexed by a factor K = 10 to 25. This networkmust be removed
when 2/4 wire conversion is implementedwith 2nd generationCOMBO (EG.TS5070).
4) Thestructure ofthisnetwork shall copy thelineimpedance, Zline,multiplexed by a factorK =10 to 25 andcompensate theeffectof CCOMP
ontranshybrid rejection. This networkmustbe removed when2/4wire conversion is implemented with2nd generation COMBO(EG.TS5070).
5) The CINT value depends on the ringing frequency F
.
6) Value relatedto Vb= 48V application,for application with different battery voltages should be properly dimensioned (see Fig.4).
7) Ex.: For line leakageresistance to GND equal to 500K
, the common mode rejection is 5V
P
withoutCS and about 10Vp with CS -
Fr (Hz)
CINT (nF)
16/18
680
19/21
580
22/27
470
28/32
390
33/38
330
39/46
270
47/55
220
56/68
180
The CINT value can be optimized experimentally
for each application choosingthe lower value that
in correspondanceof the lower ringing frequency,
the minimum line lenghtand the higher number of
ringersdoesn’t producefalse off-hook detection.
1
2
Π
f
o
(
50 R
P
)
with f
o
= 200KHz
(
K
x
Zline
)
(
25
K
x CCOMP
) (
note 4
)
Table 2
L3000S - L3092
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