Datasheet

MAX11600–MAX11605
External Reference
The external reference can range from 1.0V to V
DD
. For
maximum conversion accuracy, the reference must be
able to deliver up to 30µA and have an output impedance
of 1kΩ or less. If the reference has a higher output imped-
ance or is noisy, bypass it to GND as close as possible to
AIN_/REF (MAX11600/MAX11601/MAX11604/MAX11605)
or REF (MAX11602/MAX11603) with a 0.1µF capacitor.
Transfer Functions
Output data coding for the MAX11600–MAX11605 is
binary in unipolar mode and two’s complement binary in
bipolar mode with 1 LSB = V
REF
/2
N
where N is the num-
ber of bits (8). Code transitions occur halfway between
successive-integer LSB values. Figures 12 and 13 show
the input/output (I/O) transfer functions for unipolar and
bipolar operations, respectively.
SCAN1 SCAN0 SCANNING CONFIGURATION
0 0 Scans up from AIN0 to the input selected by CS3–CS0 (default setting).
0 1 Converts the input selected by CS3–CS0 eight times.*
MAX11600/MAX11601: Scans upper half of channels.
Scans up from AIN2 to the input selected by CS1 and CS0. When CS1 and CS0 are set for AIN0, AIN1, and
AIN2, the scanning stops at AIN2 (MAX11600/MAX11601).
MAX11602/MAX11603: Scans upper quartile of channels.
Scans up from AIN6 to the input selected by CS3–CS0. When CS3–CS0 is set for AIN0–AIN6, the scanning
stops at AIN6 (MAX11602/MAX11603).
10
MAX11604/MAX11605: Scans upper half of channels.
Scans up from AIN6 to the input selected by CS3–CS0. When CS3–CS0 is set for AIN0–AIN6, the scanning
stops at AIN6 (MAX11604/MAX11605).
1 1 Converts the channel selected by CS3–CS0.*
Table 5. Scanning Configuration
* When operating in external clock mode, there is no difference between SCAN[1:0] = 01 and SCAN[1:0] = 11 and converting continues
until a not acknowledge occurs.
SEL2 SEL1 SEL0
REFERENCE
VOLTAGE
AIN_/REF
(MAX11600/
MAX11601/
MAX11604/
MAX11605)
REF
(MAX11602/
MAX11603)
INTERNAL
REFERENCE STATE
00X V
DD
Analog input Not connected Always off
0 1 X External reference Reference input Reference input Always off
1 0 0 Internal reference Analog input Not connected AutoShutdown
1 0 1 Internal reference Analog input Not connected Always on
1 1 X Internal reference Reference output Reference output Always on
Table 6. Reference Voltage, AIN_/REF, and REF Format
X = Don’t care.
2.7V to 3.6V and 4.5V to 5.5V, Low-Power,
4-/8-/12-Channel 2-Wire Serial 8-Bit ADCs
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