xe88lc05 ETC-unknow, xe88lc05 Datasheet - Page 21

• Manufacturer Part Number: xe88lc05
• Description: 16 10 Bit Data Acquisition Ultra Low-power Microcontroller
• Manufacturer: ETC-unknow

8.4 Analog to digital converter (ADC)
8.5 ADC performances
Table 8.4:
Note:
21
Note: N
Figure 8.2:
input
sample
conversion
index
START
N
NResol
UMCONV
Resol
VINR
smax
Nend
sym
DNL
Ninit
INL
fs
smax input samples.
N
smax = 8*2
During the elementary conversions, the operation of the converter is the same as in a sigma
delta modulator. During one conversion sequence, the elementary conversions are alterna-
tively performed with direct and crossed PGA-ADC differential inputs, so that when two ele-
mentary conversions or more are performed, the offset of the converter is cancelled.
umCONV
umCONV
1 2
1st elementary
conversion
Number of elementary conversions in
= 2
elementary conversions are performed, each elementary conversion being made of
The whole analog to digital conversion sequence is basically made of an initialisation, a set of
Nelconv elementary incremental conversions and finally a termination phase(N
by 2 bits on RegACCfg0). The result is a mean of the results of the elementary conversions.
Some additional clock cycles (N
conversion properly.
ADC Performances
1) Only powers of 2
2) INL is defined as the deviation of the DC transfer curve from the best fit straight line. This
Number of periods for incremental
Number of periods for incremental
OSR
1
Conversion sequence. smax is the oversampling rate.
NELCONV
Differential non-linearity
conversion initialization
conversion termination
Numerical resolution
Integral non-linearity
sampling frequency
Oversampling Ratio
incremental mode
smax 1 2
description
Input range
Resolution
2nd elementary
conversion
Data Acquisition Microcontroller
2
smax
INIT
min
-0.5
-0.1
10
-3
6
8
1
+N
END
) clock cycles are used to initiate and terminate the
typ
elementary
conversion
N
umConv
1024
max
512
0.5
0.1
16
16
2
8
5
5
-1
unit
Vref
LSB
LSB
kHz
bits
bits
-
-
-
-
1 2
elementary
conversion
2, LSB at 16 bits
LSB at 16 bits
Comments
XE88LC05
N
umConv
3
1
1
smax
umCONV
D0109-40
END
is set