Datasheet

23
MAX11135–MAX11143
500ksps, Low-Power, Serial 12-/10-/8-Bit,
4-/8-/16-Channel ADCs
into ADC memory, the pattern may be repeated indefi-
nitely or changed at any time.
For example, the maximum throughput of MAX11135–
MAX11143 is 500ksps. Traditional ADC scan modes
allow up to 16-channel conversions in ascending order.
In this case, the effective throughput per channel is
500ksps/16 channel or 31.25ksps. The maximum input
frequency that the ADC can resolve (Nyquist Theorem)
is 15.625kHz. If all 16 channels must be measured, with
some channels having greater than 15.625kHz input
frequency, the user must revert back to manual mode
requiring constant communication on the serial interface.
SampleSet technology solves this problem. Figure 9 pro-
vides a SampleSet use-model example.
Figure 9. SampleSet Use-Model Example
SAMPLE SET
(DEPTH = 256)
1
ST
CYCLE2
ND
CYCLE3
RD
CYCLE4
TH
CYCLE5
TH
CYCLE6
TH
CYCLE7
TH
CYCLE8
TH
CYCLE9
TH
CYCLE
POTENTIAL SampleSet PATTERN
CHANNEL:
ENTRY NO.:
AIN2/
AIN3
AIN2/
AIN3
AIN2/
AIN3
AIN2/
AIN3
AIN0 AIN1 AIN0 AIN0 AIN0 AIN0
25413713613513413313213113012912812712612512412312212112054321 255 256
AIN1 AIN1 AIN1 AIN1AIN4 AIN5 AIN6 AIN7 AIN8 AIN9 AIN10 AIN11 AIN12 AIN13 AIN14 AIN15
120 CONVERSIONS:
AIN0 AND AIN1
135
1
122
123
124
125
256
120 CONVERSIONS:
AIN0 AND AIN1
SampleSet REPEATS: LENGTH = 256
100kHz
100 CYCLES
10kHz
10 CYCLES
1kHz
1 CYCLES
CS
AIN0
AIN1
2
3
5
7
9
11
13
15
17
19
21
23
25
27
29
4
6
8
10
12
14
16
t
S
= 1/f
S
= 1/500ksps = 2µs
T
S
T
S
f
in
= 100kHz
18
31
20
22
24
26
28
30
32
5µs
5µs
10µs
10µs
FULLY
DIFFERENTIAL
AIN0
ANALOG
INPUTS
AIN1
AIN2
AIN3
AIN4
AIN5
AIN6
AIN7
AIN8
AIN11
AIN12
AIN13
AIN9
AIN10