ADUC834BSZ Datasheet, PDF (22/80 Pages) Analog Devices – MicroConverter, Dual 16-Bit/24-Bit

ADuC834
PRIMARY AND AUXILIARY ADC NOISE
PERFORMANCE
Tables X, XI, and XII show the output rms noise in ␮V and
output peak-to-peak resolution in bits (rounded to the nearest
0.5 LSB) for some typical output update rates on both the primary
and auxiliary ADCs. The numbers are typical and are generated
at a differential input voltage of 0 V. The output update rate is
selected via the Sinc Filter (SF) SFR. It is important to note
that the peak-to-peak resolution figures represent the resolution
for which there will be no code flicker within a six-sigma limit.
The QuickStart Development system PC software comes
complete with an ADC noise evaluation tool. This tool can be
easily used with the evaluation board to see these figures from
silicon.
SF
Word
13
69
255
Table X. Primary ADC, Typical Output RMS Noise (␮V)
Typical Output RMS Noise vs. Input Range and Update Rate; Output RMS Noise in ␮V
Data Update
Input Range
Rate (Hz)
؎20 mV ؎40 mV ؎80 mV ؎160 mV
؎320 mV ؎640 mV ؎1.28 V
105.3
19.79
5.35
1.50
1.50
1.60
1.75
0.60
0.65
0.65
0.65
0.35
0.35
0.37
0.37
3.50
4.50
6.70
0.65
0.95
1.40
0.37
0.51
0.82
؎2.56 V
11.75
2.30
1.25
SF
Word
13
69
255
Table XI. Primary ADC, Peak-to-Peak Resolution (Bits)
Peak-to-Peak Resolution vs. Input Range and Update Rate; Peak-to-Peak Resolution in Bits
Data Update
Input Range
Rate (Hz)
؎20 mV ؎40 mV ؎80 mV ؎160 mV
؎320 mV ؎640 mV ؎1.28 V ؎2.56 V
105.3
19.79
5.35
12
13
14
15
13.5
14
15
16
14
15
16
17
15
15.5
16
16
17
17.5
18
18.5
18
18.5
19
19.5
Typical RMS Resolution vs. Input Range and Update Rate: RMS Resolution in Bits*
SF
Word
Data Update
Input Range
Rate (Hz)
؎20 mV ؎40 mV ؎80 mV ؎160 mV
؎320 mV ؎640 mV
13
105.3
69
19.79
255
5.35
14.7
15.7
16.7
17.7
16.2
16.7
17.7
18.7
16.7
17.7
18.7
19.7
17.7
18.2
19.7
20.2
20.7
21.2
*Based on a six-sigma limit, the rms resolution is 2.7 bits greater than the peak-to-peak resolution.
؎1.28 V
18.7
20.7
21.7
؎2.56 V
18.7
21.2
22.2
Table XII. Auxiliary ADC
Typical Output RMS Noise vs. Update Rate*
Output RMS Noise in ␮V
Peak-to-Peak Resolution vs. Update Rate¹
Peak-to-Peak Resolution in Bits
SF
Word
Data Update
Rate (Hz)
13
105.3
69
19.79
255
5.35
*ADC converting in Bipolar mode
Input Range
2.5 V
10.75
2.00
1.15
SF
Word
13
69
255
Data Update
Rate (Hz)
105.3
19.79
5.35
Input Range
2.5 V
16²
16
16
NOTES
1_{ADC converting in Bipolar mode}
2_{In Unipolar mode, peak-to-peak resolution at 105 Hz is 15 bits.}
–22–
REV. A