CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. Absolute maximum ratings are limiting values, applied individually, beyond which the serviceability of the circuit may be impaired. Functional
operability under any of these conditions is not necessarily implied.
2.
θ
JA
is measured with the component mounted on an evaluation PC board in free air.
Electrical Specifications
PARAMETER
On Hook Power Dissipation
Off Hook Power Dissipation
Off Hook I
VCC
Off Hook I
VCC
Off Hook I
BAT
Off Hook Loop Current
Off Hook Loop Current
Off Hook Loop Current
Fault Currents
TIP to Ground
RING to Ground
TIP to RING
TIP and RING to Ground
Ring Relay Drive V
OL
Ring Relay Driver Off Leakage
Ring Trip Detection Period
Unless Otherwise Specified, V
BAT
= -24V, V
CC
= 5V, AG = BG = DG = 0V, Typical Parameters
T
A
= 25
o
C. Min-Max Parameters are Over Operating Temperature Range
CONDITIONS
I
LONG
= 0 (Note 3), V
CC
= 5V
R
L
= 600Ω, I
LONG
= 0 (Note 4), V
CC
= 5V
R
L
= 600Ω, I
LONG
= 0 (Note 3), T
A
= 0
o
C
R
L
= 600Ω, I
LONG
= 0 (Note 3), T
A
= 25
o
C
R
L
= 600Ω, I
LONG
= 0 (Notes 3, 4)
R
L
= 400Ω, I
LONG
= 0 (Note 3)
R
L
= 400Ω, V
BAT
= -21.6V, I
LONG
= 0 (Note 3)
T
A
= 25
o
C
R
L
= 200Ω, I
LONG
= 0 (Note 3)
(Note 4)
MIN
-
-
-
-
-
-
17.5
-
TYP
80
180
-
-
19
22.9
-
25
MAX
100
200
6.0
4.0
23
-
-
30
UNITS
mW
mW
mA
mA
mA
mA
mA
mA
-
-
27.5
70
30
140
0.2
-
2
-
±2
-
90
10
-
-
-
-
0.5
25
3
10.5
-
0.5
-
20
mA
mA
mA
mA
V
µA
Ring Cycles
mA
mA
ms
kΩ
Ω
(Note 4)
-
-
I
OL
= 62mA
V
RD
= 12V, RC = 1 = HIGH, T
A
= 25
o
C
R
L
= 600Ω, (Note 5)
-
-
-
5
Switch Hook Detection Threshold
Loop Current During Power Denial
Dial Pulse Distortion
Receive Input Impedance
Transmit Output Impedance
R
L
= 200Ω
(Note 4)
(Note 5)
(Note 5)
-
0
-
-
2
HC5503
Electrical Specifications
PARAMETER
2-Wire Return Loss
SR
L
LO
ER
L
SR
L
HI
Longitudinal Balance
2-Wire Off Hook
2-Wire On Hook
4-Wire Off Hook at 1kHz
Insertion Loss
2-Wire to 4-Wire at 3.4kHz
V
TR
to V
O
V
O
is the Output of the Transhybrid
Amplifier
4-Wire to 2-Wire at 300Hz
Frequency Response
Idle Channel Noise
2-Wire to 4-Wire
Idle Channel Noise
4-Wire to 2-Wire
Absolute Delay
2-Wire to 4-Wire, 4-Wire to 2-Wire
Trans Hybrid Loss
Overload Level
2-Wire to 4-Wire (On-hook)
4-Wire to 2-Wire (Off-hook, R
L
= 600Ω)
Level Linearity
2-Wire to 4-Wire, 4-Wire to 2-Wire
At 1kHz, (Note 4) Referenced to 0dBm Level
+3 to -40dBm
-40 to -50dBm
-50 to -55dBm
Power Supply Rejection Ratio
V
CC
to 2-Wire
V
CC
to Transmit
V
BAT
to 2-Wire
V
BAT
to Transmit
V
CC
to 2-Wire
V
CC
to Transmit
V
BAT
to 2-Wire
V
BAT
to Transmit
Logic Input Current (RS, RC, PD)
0V
≤
V
IN
≤
2.4V
200 - 16kHz, R
L
= 200Ω
(Note 4)
30 - 60Hz, R
L
= 200Ω
-
-
-
-
-
-
±0.05
±0.1
±0.3
dB
dB
dB
Balance Network Set Up for 600Ω Termination at
1kHz
V
CC
= +5V
2.5
3.1
-
-
-
-
V
PEAK
V
PEAK
(Note 4)
200 - 3400Hz Referenced to Absolute Loss at 1kHz
and 0dBm Signal Level (Note 4)
0dBm Input Level, Referenced 600Ω
1V
RMS
200Hz - 3400Hz, (Note 4) IEEE Method
0
o
C
≤
T
A
≤
75
o
C
Unless Otherwise Specified, V
BAT
= -24V, V
CC
= 5V, AG = BG = DG = 0V, Typical Parameters
T
A
= 25
o
C. Min-Max Parameters are Over Operating Temperature Range
(Continued)
CONDITIONS
Referenced to 600Ω +2.16µF (Note 4)
-
-
-
15.5
24
31
-
-
-
dB
dB
dB
MIN
TYP
MAX
UNITS
53
53
50
58
58
58
-
-
-
dB
dB
dB
-
-3.8
-
-
-
-
-
(Note 5)
-
30
±0.05
-4.0
±0.02
1
-89
1
-89
±0.2
-4.2
±0.05
5
-85
5
-85
dB
dB
dB
dBrnC
dBm0p
dBrnC
dBm0p
µs
dB
-
40
2
-
35
35
20
20
35
35
35
35
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
±20
dB
dB
dB
dB
dB
dB
dB
dB
µA
3
HC5503
Electrical Specifications
PARAMETER
Logic Inputs
Logic ‘0’ V
IL
Logic ‘1’ V
IH
SHD Output
Logic ‘0’ V
OL
Logic ‘1’ V
OH
I
LOAD
800µA, V
CC
= 5V
I
LOAD
40µA, V
CC
= 5V
-
2.7
0.1
-
0.4
5.0
V
V
-
2.0
-
-
0.8
5.5
V
V
Unless Otherwise Specified, V
BAT
= -24V, V
CC
= 5V, AG = BG = DG = 0V, Typical Parameters
T
A
= 25
o
C. Min-Max Parameters are Over Operating Temperature Range
(Continued)
CONDITIONS
MIN
TYP
MAX
UNITS
NOTES:
3. I
LONG
= Longitudinal Current.
4. These parameters are controlled by design or process parameters and are not directly tested. These parameters are characterized upon initial
design release, upon design changes which would affect these characteristics, and at intervals to assure product quality and specification com-
pliance.
5. Guaranteed by design, not tested.
4
HC5503
Design Information
Line Feed Amplifiers
The line feed amplifiers are high power operational
amplifiers and are connected to the subscriber loop through
150Ω of feed resistance as shown in Figure 1. The feed
resistors and synthesized impedance via feedback provide a
600Ω balanced load for the 2-wire to 4-wire transmission.
The tip feed amplifier is configured as a unity gain
noninverting buffer. A -4V bias (derived from the negative
battery (V
BAT
) in the bias network) is applied to the input of
the amplifier. Hence, the tip feed DC level is at -4V. The
principal reason for this offset is to accommodate sourcing
and sinking of longitudinal noise currents up to 15mA
RMS
without saturating the amplifier output and to provide
sufficient overhead for receive signals. The tip feed amplifier
also feeds the ring feed amplifier, which is configured as a
unity gain inverting amplifier as seen from the tip feed
amplifier. The noninverting input to the ring feed amp is
biased at a V
BAT
/2. Looking into this terminal the amplifier
has a noninverting gain of 2. Thus, the DC output at ring
feed is:
V
RF
(DC) = (4 + V
BAT
) Volts
For a -24V battery, V
RF
= -20V. Hence, the nominal battery
feed across the loop provided by the SLIC is 16V. When the
subscriber goes off-hook this DC feed causes current
(metallic current) to flow around the loop.
Va
+
∆I
L
TIP
R
B1
TIP FEED
150Ω
The received audio signal R
X
is fed into the tip feed amplifier
and appears at the tip feed terminal. It is also fed through the
ring feed amplifier and is inverted. Thus, a differential signal of
2V
RX
appears between tip feed and ring feed. The R
X
signal
causes AC audio currents to flow around the loop which are
then AC coupled to the earpiece of the telephone set.
2-Wire Impedance Matching
The HC5503 is optimized for operation with a -24V battery.
Impedance matching to a 600Ω load, is achieved through
the combination of the feed resistors (R
B1
, R
B2
) and
negative feedback through resistor R
2
(reference Figure 1).
R
B1
and R
B2
are sense resistors that detect loop current
and provide negative feedback to synthesize the remaining
300Ω required to match a 600Ω line.
The impedance looking into the tip terminal is 150Ω (R
B1
)
plus the synthesized impedance of the tip amplifier. The
synthesized tip impedance is equal to the tip feed voltage Va
divided by
∆IL.
(Note, the tip feed amplifier is a voltage
follower. Thus, the tip feed voltage is equal to the receive
input voltage V
RX
, both are labeled Va.) The synthesized
impedance of the ring terminal is calculated the same way
and is the ring feed voltage divided by
∆IL.
(Note, the ring
feed voltage is equal in magnitude to the tip feed voltage, but
opposite in phase as a result of the ring feed amplifier gain.)
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