AD7707 Analog Devices, AD7707 Datasheet - Page 16

• Manufacturer Part Number: AD7707
• Manufacturer: Analog Devices

Specifications of AD7707

• Resolution (bits): 16bit
• # Chan: 3
• Sample Rate: n/a
• Interface: Ser,SPI
• Analog Input Type: Diff-Uni,SE-Bip
• Ain Range: Bip (Vref)/(PGA Gain),Bip 10V,Bip 5.0V,Uni (Vref)/(PGA Gain),Uni 10V,Uni 5.0V
• Adc Architecture: Sigma-Delta
• Pkg Type: SOIC,SOP

AD7707
OUTPUT NOISE FOR HIGH LEVEL INPUT CHANNEL
AIN3 (5 V OPERATION)
Table 11 shows the AD7707 output rms noise and peak-to-peak
resolution in unbuffered mode for the selectable notch and −3 dB
frequencies for the part, as selected by FS0, FS1, and FS2 of the
clock register. The numbers given are for the ±10 V, ±5 V, 0 to
5 V and 0 V to 10 V ranges with a V
HICOM = AGND, and AV
and are generated at an analog input voltage of 0 V. Table 12
meanwhile shows the output rms noise and peak-to-peak
resolution in buffered mode. It is important to note that these
numbers represent the resolution for which there is no code
flicker. They are not calculated based on rms noise, but on
peak-to-peak noise. Operating the high level channel with a
gain of 2 in bipolar mode gives an operating range of ±10 V.
Operating at a gain of 2 in unipolar mode gives a range of 0 V
to +10 V. Operating the high level channel with a gain of 4 in
Table 11. Output RMS Noise/Peak-to-Peak Resolution vs. Gain and Output Update Rate @ 5 V AIN3 Unbuffered Mode Only
Filter First Notch
and Output Data
Rate
MCLK IN = 2.4576 MHz
10 Hz
50 Hz
60 Hz
250 Hz
500 Hz
MCLK IN = 1 MHz
4.05 Hz
20 Hz
25 Hz
100 Hz
200 Hz
Table 12. Output RMS Noise/Peak-to-Peak Resolution vs. Gain and Output Update Rate @ 5 V AIN3 Buffered Mode Only
Filter First Notch
and Output Data
Rate
MCLK IN = 2.4576 MHz
10 Hz
50 Hz
60 Hz
250 Hz
500 Hz
MCLK IN = 1 MHz
4.05 Hz
20 Hz
25 Hz
100 Hz
200 Hz
−3 dB
Frequency
2.62 Hz
13.1 Hz
15.72 Hz
65.5 Hz
131 Hz
1.06 Hz
5.24 Hz
6.55 Hz
26.2 Hz
52.4 Hz
−3 dB
Frequency
2.62 Hz
13.1 Hz
15.72 Hz
65.5 Hz
131 Hz
1.06 Hz
5.24 Hz
6.55 Hz
26.2 Hz
52.4 Hz
DD
= 5 V. These numbers are typical
RMS Noise
(μV)
5.10
15.82
20.36
430
2350
5.13
18.9
23.7
406
2184
RMS Noise
(μV)
7.4
22.2
26.6
475
2423
7.63
20.25
23.5
377
2226
REF
of 2.5 V, VBIAS = 2.5 V,
±10 V Range
±10 V Range
P-P (Bits)
Resolution
16
16
16
13
10
16
16
16
13
10.5
P-P (Bits)
Resolution
16
16
16
13
10.5
16
16
16
13
10.5
5.2
14.3
15.85
187
1097
5.45
13.3
14.6
210
1132
RMS Noise
(μV)
RMS Noise
(μV)
3.52
9.77
12.29
212
1287
3.53
13.25
15.3
174
1144
Rev. B | Page 16 of 52
±5 V Range
±5 V Range
P-P (Bits)
Resolution
16
16
16
13
10.5
16
16
16
13
10.5
P-P (Bits)
Resolution
16
16
16
13
10
16
16
16
13
10.5
bipolar mode gives the ±5 V operating range. Operating at a gain
of 4 in unipolar mode gives an operating range of 0 V to 5 V.
Noise for all input ranges is shown in Output Noise For High Level
Input Channel, AIN3 section. The output noise comes from two
sources. The first is the electrical noise in the semiconductor
devices (device noise) used in the implementation of the modula-
tor. Secondly, when the analog input is converted into the digital
domain, quantization noise is added. The device noise is at a low
level and is independent of frequency. The quantization noise
starts at an even lower level but rises rapidly with increasing
frequency to become the dominant noise source. The numbers
in Table 11 and Table 12 are given for the bipolar input ranges.
For the unipolar ranges the rms noise numbers are the same as
the bipolar range, but the peak-to-peak resolution is now based
on half the signal range, which effectively means losing 1 bit of
resolution.
RMS Noise
(μV)
7.4
22.2
26.6
475
2423
7.63
20.25
23.5
377
2226
RMS Noise
(μV)
5.10
15.82
20.36
430
2350
5.13
18.9
23.7
406
2184
0 V to 10 V Range
0 V to 10 V Range
P-P (Bits)
Resolution
16
16
16
12
9.5
16
16
16
12
9.5
16
16
16
16
9.5
P-P (Bits)
Resolution
16
16
12
9
12
RMS Noise
(μV)
5.2
14.3
15.85
187
1097
5.45
13.3
14.6
210
1132
RMS
Noise (μV)
3.52
9.77
12.29
212
1287
3.53
13.25
15.3
174
1144
0 to 5 V Range
0 V to 5 V Range
P-P (Bits)
Resolution
16
16
16
12
9
16
16
15.5
12
9.5
P-P (Bits)
16
15.5
Resolution
16
16
16
12
9.5
16
12
9.5