Data Sheet
February 1998
T7502 Dual PCM Codec with Filters
Transmission Characteristics (continued)
ac Transmission Characteristics (continued)
Table 9. Noise
Parameter
Transmit Noise, A-Law
Receive Noise, A-Law
Noise, Single Frequency
Symbol
NXp
Test Conditions
Min Typ Max
Unit
Input amplifier gain = 36 dB
PCM code is A-law positive one.
—
—
—
–68.5 –68
dBm0p
dBm0p
dBm0
NRp
–82
—
–75
–53
NRS
f = 0 kHz—100 kHz,
VFXIN = 0 Vrms, measurement at
VFRO, DR = DX
Power Supply Rejection Transmit
Power Supply Rejection Receive
PSRX
PSRX
VDD = 5.0 Vdc + 100 mVrms:
f = 0 kHz—4 kHz
36
30
—
—
—
—
dB
dB
f = 4 kHz—50 kHz
PCM code is positive one LSB.
VDD = 5.0 Vdc + 100 mVrms:
f = 0 kHz—4 kHz
36
40
30
—
—
—
—
—
—
dB
dB
dB
f = 4 kHz—25 kHz
f = 25 kHz—50 kHz
Spurious Out-of-Band Signals at
VFRO Relative to Input
SOS
0 dBm0, 300 Hz—3400 Hz input
PCM code applied:
4600 Hz—7600 Hz
7600 Hz—8400 Hz
8400 Hz—50 kHz
—
—
—
—
—
—
–30
–40
–30
dB
dB
dB
Table 10. Receive Gain Relative to Gain at 1.02 kHz
Frequency (Hz)
Below 3000
3140
Min
–0.150
–0.570
–0.735
—
Typ
±0.04
±0.04
–0.50
–10.70
—
Max
0.150
0.150
0.010
–9.400
–28
Unit
dB
dB
dB
dB
dB
3380
3860
4600 and above
—
Table 11.Transmit Gain Relative to Gain at 1.02 kHz
Frequency (Hz)
16.67
Min
—
Typ
–50
Max
–30
Unit
dB
dB
dB
dB
dB
dB
dB
dB
dB
dB
40
—
–34
–26
50
—
–36
–30
60
—
–50
–30
200
–1.800
–0.150
–0.570
–0.735
—
–0.5
±0.04
±0.04
–0.50
–10.70
—
0
300 to 3000
3140
0.150
0.150
0.010
–9.400
–32
3380
3860
4600 and above
—
8
Lucent Technologies Inc.
AGERE [ AGERE SYSTEMS ]
