CSP1027 Datasheet, PDF (53/64 Pages) Agere Systems – CSP1027 Voice Band Codec for Cellular Handset and Modem Applications

Data Sheet
December 1999
CSP1027 Voice Band Codec for
Cellular Handset and Modem Applications
10 Analog Characteristics and Requirements (continued)
10.3 Digital-to-Analog Path
Table 19. D/A Signal to Distortion Plus Noise Ratio (0 dB Output Setting)
Output Signal Level
0 dBm0
–10 dBm0
–30 dBm0
–40 dBm0
–45 dBm0
–55 dBm0
Min
Max
Unit
72
—
dB
62
—
dB
42
—
dB
32
—
dB
27
—
dB
17
—
dB
Notes:
The D/A signal to distortion plus noise ratio decreases by 3 dB for each 3 dB gain step below 0 dB. The D/A SDNR is specified with a differential
load. For a single-ended load, the D/A SDNR is degraded by about 6 dB.
The D/A signal to distortion plus noise ratio is valid for sampling rates up to 16 kHz. For sampling rates between 16 kHz and 24 kHz, the signal
to distortion plus noise ratio is no better than 60 dB.
Table 20. D/A Relative Gain Accuracy*
Output Signal Level
+3 dBm0 to –40 dBm0
–40 dBm0 to –50 dBm0
–50 dBm0 to –55 dBm0
Min
Max
Unit
–0.1
0.1
dB
–0.4
0.4
dB
–1.2
1.2
dB
* Gain is relative to the 0 dBm0 signal level. Absolute gain accuracy at the 0 dBm0 signal level is ±0.18 dB. Digital-to-analog path gain is spec-
ified with a differential load; a single-ended load adds ±0.1 dB to absolute gain.
Table 21. D/A Output Gain Adjustment
Gain Setting
0 dB
–3 dB
–6 dB
–9 dB
–12 dB
.
.
.
–42 dB
–45 dB
Min
Typ
Max
Unit
–0.2
0
0.2
dB
–3.21
–3.01
–2.81
dB
–6.22
–6.02
–5.82
dB
–9.23
–9.03
–8.83
dB
–12.24
–12.04
–11.84
dB
.
.
.
.
.
.
.
.
.
.
.
.
–42.34
–42.14
–41.94
dB
–45.35
–45.15
–44.95
dB
Lucent Technologies Inc.
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