MSP58C20 Datasheet, PDF (9/17 Pages) Texas Instruments – AUDIO-BAND CONVERTER

MSP58C20
AUDIO-BAND CONVERTER
SPSS015B – DECEMBER 1993 – REVISED JULY 1996
PARAMETER MEASUREMENT INFORMATION
The receive characteristics in the electrical characteristics table are measured by activating the MSP58C20 receive
path through a digital modulator. This modulator consists of two functional blocks (see Figure 1 and Figure 2)
connected in series. The output of the decoder (see Figure 2) is shown in Table 1.
3
3
/
Z ^–1
/
Em
3 LSBs
BITS (16 –1) /
+
16
/
/
Di
16
13 MSBs
Figure 1. 16- to 13-Bit Modulator at 512-kHz Sampling Rate
512 kHz
13
Di _{512 kHz} /
+
16
Ux
11
12
/
1/ _{32 / +}
/
Vx 4 MSBs
/
Dx
Decoder
Rx
12
Sx
16
12
3
/
Z ^–1
+ 64
/
Dx
16
16
3
/
Z ^–1 +
/
2048
/
Figure 2. Sigma-Delta-2 Modulator at 512-kHz Sampling Rate
Table 1. Dx Decoder
DECODER INPUT
Vx (11) Vx (10) Vx (9) Vx (8)
0
1
X
X
0
0
1
X
0
0
0
1
0
0
0
0
1
1
1
1
1
1
1
0
1
1
0
X
1
0
X
X
Dx (2)
H
H
H
H
L
L
L
L
DECODER OUTPUT
Dx (1) Dx (0) DIGS
H
L
L
H
L
L
H
L
L
H
H
L
L
H
H
H
L
H
H
L
H
H
L
H
DIGL
H
H
H
L
L
H
H
H
DIGS
DIGL
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