CS5320-KL1 View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
CS5320-KL1 Datasheet PDF : 38 Pages
| |||
CS5320/21/22
2.8 Performance
Figure 22, 23 and 24 illustrate the spectral perfor-
mance of the CS5321/22 and CS5320/22 chipsets
when operating from a 1.024 MHz master clock.
Ten 1024 point FFTs were averaged to produce the
plots.
Figure 22 illustrates the chip set with a 100 Hz,
-20 dB input signal. The sample rate was set at 1
kHz. Dynamic range is 122 dB.
The dynamic range calculated by the test soft-ware
is reduced somewhat in Figures 23 and 24 because
of jitter in the signal test oscillator. Jitter in the
100 Hz signal source is interpreted by the signal
processing software to be increased noise.
The choice of master clock frequency will affect
performance. The CS5320/21 will exhibit the best
Signal/ Distortion performance with slower modu-
lator sampling clock rates as slower sample rates
allow more time for amplifier settling.
For lowest offset drift, the CS5320/21 should be
operated with MCLK = 1.024 MHz and HBR = 1.
Slower modulator sampling clock rates will exhibit
more offset drift. Changing MCLK to 512 kHz
(HBR = 1) or changing HBR to zero (MCLK =
1.024 MHz) will cause the drift rate to double. Off-
set drift is not linear over temperature so it is diffi-
cult to specify an exact drift rate. Offset drift
characteristics vary from part to part and will vary
as the power supply voltages vary. Therefore, if the
CS5320/21 is to be used in precision dc measure-
ment applications where offset drift is to be mini-
mized, the power supplies should be well
regulated. The CS5320/21 will exhibit about
6 ppm/°C of offset drift with MCLK = 1 and HBR
= 1.
Gain drift of the CS5320/21 itself is about
5 ppm/°C and is not affected by either modulator
sample rate or by power supply variation.
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
0
Dynamic Range = 122.0 dB
HBR = 1
OFST = 0
LPWR = 0
500
Figure 22. 1024 Point FFT Plot with -20 dB Input, 100
Hz Input, ten averages
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
0
see text
S/D = 116.0 dB
S/N = 118.4 dB
S/N+D = 114.2 dB
HBR = 1
OFST = 0
LPWR = 0
500
Figure 23. 1024 Point FFT Plot with Full Scale Input,
100 Hz Input, HBR = 1, ten averages
0
-20
-40
-60
-80
-100
-120
-140
-160
-180
0
see text
S/D = 122.7 dB
S/N = 117.1 dB
S/N+D = 116.4 dB
HBR = 0
OFST = 0
LPWR = 0
500
Figure 24. 1024 Point FFT Plot with Full Scale Input,
100 Hz Input, HBR = 0, ten averages
22
DS454PP1
Share Link: 