xe8802 Semtech Corporation, xe8802 Datasheet - Page 125

• Manufacturer Part Number: xe8802
• Description: Data Acquisition Soc With 16+10 Bit Zoomingadc? Embedded Risc Controller And Lcd Driver
• Manufacturer: Semtech Corporation

17.7.4
As mentioned previously, the whole conversion sequence is made of a set of N
conversions. This number is set with the word SET_NELC[1:0] in binary steps (see Table 17-21) given by:
As already mentioned, N
17.7.5
The theoretical resolution of the ADC, without considering thermal noise, is given by:
© Semtech 2006
n
N
=
ELCONV
Elementary Conversions
Resolution
2
⋅
log
=
2
2
(
OSR
SET_NELC[1
Table 17-22. Resolution vs. SET_OSR[2:0] and SET_NELC[1:0] settings
)
+
ELCONV
log
Figure 17-6. Resolution vs. SET_OSR[2:0] and SET_NELC[2:0]
2
(
SET_OSR
N
[2:0]
:
Table 17-21. Number of elementary conversion settings
must be equal or greater than 2 to reduce internal amplifier offsets.
ELCONV
000
001
010
011
100
101
110
111
(RegAcCfg0[6:5])
0]
SET_NELC[1:0]
)
due to output register size RegAcOut[15:0])
(shaded area: resolution truncated to 16 bits
(-)
(Bits)
00
01
10
11
17
15
13
11
9
7
5
000
00
10
12
14
16
16
16
6
8
XE8802 Sensing Machine Data Acquisition MCU
SET_NELC=
001
010
01
11
13
15
16
16
16
7
9
SET_NELC
11
10
01
00
17-13
SET_OSR
011
# of Elementary
Conversions
N
10
ELCONV
100
10
12
14
16
16
16
16
with ZoomingADC™ and LCD driver
8
1
2
4
8
101
(-)
11
11
13
15
16
16
16
16
110
9
(Eq. 14)
(Eq. 15)
111
ELCONV
elementary incremental
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