L7556, L7557 Low-Power SLICs
with Battery Switch
Data Sheet
January 2000
Electrical Characteristics (continued)
Table 8. ac Feed Characteristics
Parameter
Min
150
—
Typ
—
Max
1300
46
Unit
Ω
ac Termination Impedance1:
Longitudinal Impedance2 (See Figure 8.)
40
Ω
Total Harmonic Distortion—200 Hz to 4 kHz2:
—
—
—
—
0.3
1.0
%
%
Off-hook
On-hook
Transmit Gain, f = 1 kHz (PT/PR to VITR)
Transmit Accuracy in dB
–122 –125 –128
V/A
dB
–0.18
0
0.18
Receive + Gain, f = 1 kHz (RCVP to PT/PR)
Receive – Gain, f = 1 kHz (RCVN to PT/PR)
Receive Accuracy in dB
7.84
8.00
8.16
—
—
dB
–7.84 –8.00 –8.16
–0.18
0
0.18
Gain vs. Frequency (transmit and receive) (600 Ω termination; reference 1 kHz2):
–1.00
–0.3
–3.0
—
0.0
0.0
–0.1
—
0.05
0.05
0.3
dB
dB
dB
dB
200 Hz to 300 Hz
300 Hz to 3.4 kHz
3.4 kHz to 16 kHz
16 kHz to 266 kHz
2.0
Gain vs. Level (transmit and receive)(reference 0 dBV2):
–50 dB to +3 dB
–0.05
0
0.05
dB
Return Loss3:
20
26
24
29
—
—
dB
dB
200 Hz to 500 Hz
500 Hz to 3400 Hz
2-wire Idle-channel Noise (600 Ω termination):
Psophometric
C-message
3 kHz Flat
—
—
—
–87
2
10
–77 dBmp
12
20
dBrnC
dBrn
Transmit Idle-channel Noise:
Psophometric
—
—
—
–82
7
15
–77 dBmp
C-message
3 kHz flat
12
20
dBrnC
dBrn
Transhybrid Loss3:
200 Hz to 500 Hz
500 Hz to 3400 Hz
21
26
24
29
—
—
dB
dB
1. Set by external components. Any complex impedance R1 + R2 || C between 150 Ω and 1300 Ω can be synthesized.
2. This parameter is not tested in production. It is guaranteed by design and device characterization.
3. Return loss and transhybrid loss are functions of device gain accuracies and the external hybrid circuit. Guaranteed performance assumes
1% tolerance external components.
10
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
