HC5515
in Figure 7. Note: I
DCMET
resistor between tip and ring.
is established with a series 600Ω
Notes
2. Overload Level (Two-Wire port) - The overload level is
specified at the 2-wire port (V ) with the signal source at the
14. Two-Wire to Four-Wire (Metallic to V ) Voltage Gain - The
TX
TR0
2-wire to 4-wire (metallic to V ) voltage gain is computed
TX
4-wire receive port (E ). I
= 30mA, R = 4kΩ,
RX DCMET
SG
using the following equation.
increase the amplitude of E until 1% THD is measured at
RX
V
. Reference Figure 1.
TRO
G
= (V /V ), E = 0dBm0, V , V , and E are defined
TX TR TX TR
2-4
in Figure 7.
G
G
3. LongitudinalImpedance - The longitudinal impedance is
computed using the following equations, where TIP and RING
voltages are referenced to ground. L , L , V , V , A and
15. Current Gain RSN to Metallic - The current gain RSN to
Metallic is computed using the following equation:
ZT ZR
T
R
R
A are defined in Figure 2.
T
K = I [(R
+ R
)/(V
DC2
- V
)] K, I , R
DC1
, R ,
DC2
M
DC1
RDC
are defined in Figure 8.
RSN
RSN
M
(TIP) L = V /A ,
V
and V
ZT
T
T
RDC
(RING) L = V /A ,
ZR
R
R
16. Two-Wire to Four-Wire Frequency Response - The 2-wire to
4-wire frequency response is measured with respect to
where: E = 1V
RMS
(0Hz to 100Hz).
L
E
= 0dBm at 1.0kHz, E
= 0V, I = 23mA. The fre-
G
RX
DCMET
4. Longitudinal Current Limit (Off-Hook Active) - Off-Hook
(Active, C = 1, C = 0) longitudinal current limit is determined
quency response is computed using the following equation:
1
2
F
= 20 • log (V /V ), vary frequency from 300Hz to
2-4
TX TR
by increasing the amplitude of E (Figure 3A) until the 2-wire
longitudinal balance drops below 45dB. DET pin remains low
(no false detection).
L
3.4kHz and compare to 1kHz reading.
V
, V , and E are defined in Figure 9.
TX TR
G
5. Longitudinal Current Limit (On-Hook Standby) - On-Hook
17. Four-Wire to Two-Wire Frequency Response - The 4-wire to
(Active, C = 1, C = 1) longitudinal current limit is determined
2-wire frequency response is measured with respect to
1
2
by increasing the amplitude of E (Figure 3B) until the 2-wire
longitudinal balance drops below 45dB. DET pin remains high
(no false detection).
E
= 0dBm at 1.0kHz, E = 0V, I = 23mA. The
L
RX
G
DCMET
frequency response is computed using the following equation:
F
= 20 • log (V /E ), vary frequency from 300Hz to
4-2
TR RX
6. Longitudinal to Metallic Balance - The longitudinal to metallic
3.4kHz and compare to 1kHz reading.
balance is computed using the following equation:
V
and E are defined in Figure 9.
TR
RX
BLME = 20 • log (E /V ), where: E and V
TR TR
Figure 4.
are defined in
L
L
18. Four-Wire to Four-Wire Frequency Response - The 4-wire
to 4-wire frequency response is measured with respect to
7. Metallic to Longitudinal FCC Part 68, Para 68.310 - The
E
= 0dBm at 1.0kHz, E = 0V, I = 23mA. The
RX
G
DCMET
metallic to longitudinal balance is defined in this spec.
frequency response is computed using the following equation:
F
= 20 • log (V /E ), vary frequency from 300Hz to
8. Longitudinal to Four-Wire Balance - The longitudinal to 4-wire
4-4
TX RX
3.4kHz and compare to 1kHz reading.
balance is computed using the following equation:
V
and E are defined in Figure 9.
BLFE = 20 • log (E /V ),: E and V are defined in Figure 4.
TX
RX
L
TX
L
TX
19. Two-Wire to Four-Wire Insertion Loss - The 2-wire to 4-wire
9. Metallic to Longitudinal Balance - The metallic to longitudi-
insertion loss is measured with respect to E = 0dBm at 1.0kHz
nal balance is computed using the following equation:
G
input signal, E
the following equation:
= 0, I = 23mA and is computed using
DCMET
RX
BMLE = 20 • log (E /V ), E
TR RX
= 0,
L
where: E , V and E
are defined in Figure 5.
TR RX
L
L
= 20 • log (V /V )
TX TR
2-4
10. Four-Wire to Longitudinal Balance - The 4-wire to longitudinal
where: V , V , and E are defined in Figure 9. (Note: The
TX TR
G
balance is computed using the following equation:
fuse resistors, R , impact the insertion loss. The specified
F
insertion loss is for R = 0).
BFLE = 20 • log (E /V ), E = source is removed.
RX TR
F
L
20. Four-Wire to Two-Wire Insertion Loss - The 4-wire to 2-wire
where: E , V and E are defined in Figure 5.
RX TR
L
insertion loss is measured based upon E
= 0dBm, 1.0kHz
= 23mA and is computed using
RX
11. Two-Wire Return Loss - The 2-wire return loss is computed
input signal, E = 0, I
G
DCMET
using the following equation:
the following equation:
r = -20 • log (2V /V ).
M
S
L
= 20 • log (V /E ),
TR RX
4-2
where: Z = The desired impedance; e.g., the characteristic
D
impedance of the line, nominally 600Ω. (Reference Figure 6).
where: V and E
are defined in Figure 9.
TR RX
21. Two-Wire to Four-Wire Gain Tracking - The 2-wire to 4-wire
12. Overload Level (4-Wire port) - The overload level is specified
gain tracking is referenced to measurements taken for
at the 4-wire transmit port (V
) with the signal source (E ) at
TXO
G
E
= -10dBm, 1.0kHz signal, E
= 0, I = 23mA and is
G
RX
DCMET
the 2-wire port, I
= 23mA, Z = 20kΩ, R
= 4kΩ (Refer-
DCMET
L
SG
computed using the following equation.
ence Figure 7). Increase the amplitude of E until 1% THD is
G
G
= 20 • log (V /V ) vary amplitude -40dBm to +3dBm, or
measured at V
TXO
. Note that the gain from the 2-wire port to
2-4
TX TR
-55dBm to -40dBm and compare to -10dBm reading.
the 4-wire port is equal to 1.
V
and V are defined in Figure 9.
TR
TX
13. Output Offset Voltage - The output offset voltage is specified
with the following conditions: E = 0, I
= 23mA, Z = ∞
G
DCMET
L
22. Four-Wire to Two-Wire Gain Tracking - The 4-wire to 2-wire
and is measured at V . E , I
, V and Z are defined
TX
G
DCMET TX
L
gain tracking is referenced to measurements taken for
68