PBL 386 21/2
Ref
fig
Parameter
Conditions
Min
Typ
Max
Unit
Four-wire to longitudinal balance, BFLE
4
0.2 kHz < f < 4.0 kHz
40
50
dB
ERX
BFLE = 20 • Log
VLo
Two-wire return loss, r
|ZTR + ZL|
r = 20 • Log
|ZTR - ZL|
0.2 kHz < f < 1.0 kHz
1.0 kHz < f < 3.4 kHz, Note 3
active, IL = 0 mA
active, IL = 0 mA
active, IL = 0 mA
27
20
35
22
- 1.1
VBat +2.5
VBat +3.6
dB
dB
V
V
V
TIPX idle voltage, VTi
RINGX idle voltage, VRi
VTR
Four-wire transmit port (VTX)
Overload level, VTXO
5
Load impedance > 20 kΩ,
1.0
VPeak
1% THD, Note 4
On-hook, IL < 5mA
Output offset voltage ∆VTX
Output impedance, zTX
1.0
-100
VPeak
mV
Ω
0
15
100
50
0.2 kHz < f < 3.4 kHz
Four-wire receive port (RSN)
Receive summing node (RSN) DC voltage
Receive summing node (RSN) impedance
Receive summing node (RSN)
current (IRSN) to metallic loop current (IL)
gain,αRSN
I
RSN = -55 µA
1.15
1.25
8
1.35
20
V
Ω
0.2 kHz < f < 3.4 kHz
0.3 kHz < f < 3.4 kHz
200
ratio
Frequency response
Two-wire to four-wire, g2-4
6
relative to 0 dBm, 1.0 kHz. ERX = 0 V
0.3 kHz < f < 3.4 kHz
-0.20
-1.0
0.10
0.1
dB
dB
f = 8.0 kHz, 12 kHz, 16 kHz
Figure 4. Metallic to longitudinal and
four-wire to longitudinal balance
TIPX
VTX
RLT
C
1
<< 150 Ω, RLT =RLR =RL /2=300Ω
ωC
VTR
RT
PBL 386 21/2
ERX
VLo
RLR
RINGX
RSN
RT = 120 kΩ, RRX = 60 kΩ
RRX
Figure 5. Overload level, VTXO, four-wire
transmit port
C
TIPX
VTX
RL
1
<< RL, RL = 600 Ω
ωC
ILDC
RT
VTXO
PBL 386 21/2
RT = 120 kΩ, RRX = 60 kΩ
EL
RINGX
RSN
RRX
4