Datasheet
PIN NAME I/O FUNCTION
1, 2 REF I/O
Reference. REF is a bypass pin for the reference either driven by the internal reference buffers
or the external reference directly. Bypass these pins with 10µF capacitors to REFGND.
3, 4 REFGND I Reference Ground
5 AIN- I Negative Analog Input
6 AIN+ I Positive Analog Input
7 AGND I Analog Ground
8 OVDD I
Digital Interface Supply. Nominally at 1.8V. Bypass to DGND with a 10µF capacitor in parallel
with a 0.1µF capacitor (10µF || 0.1µF).
9 DOUT O Digital Output Data
10 DGND I Digital Ground
11 DVDD I
Digital Supply. Nominally at 1.8V. Bypass with a 10µF capacitor in parallel with a 0.1µF
capacitor (10µF || 0.1µF).
12 SCLK I Serial Clock Input
13 CNVST I
Conversion Start. The analog inputs (AIN+, AIN-) are sampled at the rising edge and conversion
process is started.
14 DIN I Serial Data Input. DIN data is latched into the serial interface on the rising edge of SCLK.
15 DGND I Digital Ground
REF
AIN-
REF
DIN
SCLK
DVDD
DGND
AGND
AVDD
REFIN
DOUT
OVDD
AGND
AIN+
+
REFGND
CNVST
AGND
DGND
REFVDD
TQFN
4mm × 4mm
MAX11903
TOP VIEW
REFGND
10
9876
11
12
13
14
15
5
4
3
2
1
16
17
18
19
20
EXPOSED PAD IS GROUND. IT MUST BE SOLDERED TO PCB.
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Maxim Integrated
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12
MAX11903 18-Bit, 1.6Msps, Low-Power,
Fully Differential SAR ADC
Pin Description
Pin Conguration