SN8P2977
8-Bit Micro-Controller with Regulator, PGIA, 24-bit ADC
SONiX TECHNOLOGY CO., LTD
Page 116
Version 1.7
Following table shows the Noise and ENOB (RMS and peak-to-peak) of the SN8P2977 ADC with different output word
rate rates and gain settings. These numbers are typical and are generated using a differential input-short condition,
ADC Vref 0.84V and 1024-data of measurement.
Gain
(PGIA x ADC)
OSR
WR
Noise Free
Resolution
(1)
Effective
Resolution
(2)
Pk-Pk Noise
(4)
RMS Noise
(3)
1 x 1(buff off)
32768
7.6Hz
18.4
21.1
4.857uV
0.736uV
1 x 1(buff on)
32768
7.6Hz
18.0
20.7
6.409uV
0.971uV
16 x 1
32768
7.6Hz
17.7
20.4
0.493uV
0.075uV
32 x 1
32768
7.6Hz
17.2
19.9
0.349uV
0.053uV
64 x 1
32768
7.6Hz
16.8
19.5
0.230uV
0.035uV
64 x 2
32768
7.6Hz
15.8
18.5
0.230uV
0.035uV
128 x 1
32768
7.6Hz
15.9
18.6
0.215uV
0.033uV
128 x 2
32768
7.6Hz
15
17.7
0.200uV
0.030uV
200 x 1
32768
7.6Hz
15.3
18
0.208uV
0.032uV
128 x 1
16384
15.3Hz
15.5
18.2
0.283uV
0.043uV
128 x 1
8192
31Hz
14.9
17.6
0.429uV
0.065uV
128 x 1
4096
61Hz
14.3
17
0.651uV
0.099uV
128 x 1
1024
244Hz
13.4
16.1
1.214uV
0.184uV
128 x 1
256
977 Hz
12.3
15
2.603uV
0.394uV
128 x 1
128
2.0 kHz
11.7
14.4
3.945uV
0.598uV
128 x 1
64
3.9 kHz
11
13.7
6.409uV
0.971uV
All Test condition: ADC 250kHz, Input-Short, Vref=0.84V, Gain = PGIA x ADC, Collect 1024 ADC date.
(1).Noise Free Resolution = Log2 (Full Scale Range / Peak-Peak Noise)
where Full Scale Range = 2 x Vref / Gain (ex. Vref=0.84V, Gain=128x)
(2).Effective Resolution = Log2 (Full Scale Range / RMS_Noise)
(3).RMS Noise = σ x LSB_Resolution
where LSB_Resolution = Full Scale Range / 2^Bit, Bit=20
σ = standard deviation of 1024 ADC output data.
(4). Peak-Peak Noise = 6.6 x RMS Noise, or code variation range x LSB_Resolution
where Code variation range = ADC counts max-min of 1024 data.
