MAX11905 Datasheet, PDF (13/29 Pages) Maxim Integrated Products – 20-Bit, 1.6Msps, Low-Power, Fully Differential

MAX11905
20-Bit, 1.6Msps, Low-Power, Fully Differential
SAR ADC
Pin Description (continued)
PIN
NAME
16
REFVDD
17, 18
19
20
—
AGND
AVDD
REFIN
EP
I/O
FUNCTION
I
Reference Buffer Supply. Nominally at 3V. Bypass to AGND with a 10µF capacitor in parallel
with a 0.1µF capacitor (10µF || 100nF).
I
Analog Ground. Bypass to AGND with a 10µF capacitor in parallel with a 0.1µF capacitor
(10µF || 100nF).
I
Analog Supply. Nominally at 1.8V.
I
Input for the Internal Reference Buffer. Voltage must be at least 300mV lower than
REFVDD voltage. If REFIN = 0V, reference buffer will be disabled.
—
Exposed Pad. Must be connected to the same plane as AGND.
Functional Diagram
REFIN
AVDD
DVDD
REFVDD
REFGND
REF
REF
AIN+
AIN-
REFERENCE
BUFFER
REFERENCE
BUFFER
20-BIT ADC
MAX11905
INTERFACE
OVDD
DIN
SCLK
DOUT
CNVST
AGND
DGND
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