T7507 Quad PCM Codec with Filters,
Termination Impedance, and Hybrid Balance
Data Sheet
August 1999
Transmission Characteristics
(continued)
ac Transmission Characteristics
(continued)
Table 19. Noise
Parameter
Transmit Noise
Receive Noise
Noise, Single Frequency
f = 0 kHz—100 kHz
Power Supply Rejection Transmit
Symbol
Test Conditions
N
XP
—
N
RP
PCM code is A-law positive one
N
RS
VF
X
IN = 0 Vrms, measurement at
VF
R
O, D
R
= D
X
PSR
X
V
DD
= 5.0 Vdc + 100 mVrms:
f = 0 kHz—4 kHz
f = 4 kHz—50 kHz
PSR
X
PCM code is positive one LSB.
V
DD
= 5.0 Vdc + 100 mVrms:
f = 0 kHz—4 kHz
f = 4 kHz—25 kHz
f = 25 kHz—50 kHz
SOS
0 dBm0, 300 Hz—3400 Hz input
PCM code applied:
4600 Hz—7600 Hz
7600 Hz—8400 Hz
8400 Hz—50 kHz
Min
—
—
—
Typ
—
—
—
Max
–68
–75
–53
Unit
dBm0p
dBm0p
dBm0
36
30
—
—
—
—
dB
dB
Power Supply Rejection Receive
36
40
30
—
—
—
—
—
—
dB
dB
dB
Spurious Out-of-band Signals at
VF
R
O Relative to Input
—
—
—
—
—
—
–30
–40
–30
dB
dB
dB
Table 20. Interchannel Crosstalk (Between Channels)
Parameter
Transmit to Receive
Crosstalk 0 dBm0
Transmit Levels
Receive to Transmit
Crosstalk 0 dBm0
Receive Levels
Transmit to Trans-
mit Crosstalk
0 dBm0 Transmit
Levels
Receive to Receive
Crosstalk 0 dBm0
Receive Levels
Symbol
CT
XX-RY
Test Conditions
f = 300 Hz—3400 Hz
idle PCM code for channel under test;
0 dBm0 into any other single-channel VF
X
IN
f = 300 Hz—3400 Hz
VF
X
IN = 0 Vrms for channel under test;
0 dBm0 code level on any other single-channel D
R
f = 300 Hz—3400 Hz
0 dBm0 applied to any single-channel
VF
X
IN except channel under test,
which has VF
X
IN = 0 Vrms
f = 300 Hz—3400 Hz
0 dBm0 code level on any single-channel D
R
except
channel under test, which has idle code applied
Min
—
Typ
–90
Max
–75
Unit
dB
CT
RX-XY
—
–90
–75
dB
CT
XX-XY
—
–90
–75
dB
CT
RX-RY
—
–90
–75
dB
Note: For interchannel, crosstalk into the transmit channels (VFxIN) can be significantly affected by parasitic capacitive feeds from VF
R
O out-
puts. PWB layouts should be arranged to keep these parasitics low. The equivalent resistor looking from VFxIN toward VITR (Figure 16)
should be kept as low as possible to minimize crosstalk. A maximum of 7 kΩ at 3 kHz is recommended. This is easily achievable in this
design with the structure as shown in Figure 16.
20
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
