MAX12553 Datasheet, PDF (24/28 Pages) Maxim Integrated Products – 14-Bit, 65Msps, 3.3V ADC

14-Bit, 65Msps, 3.3V ADC
+3.3V
1
0.1µF
2 ^MAX6029EUK30
5
3.000V
+3.3V
0.1µF
0.47µF
20kΩ
1%
20kΩ
1%
52.3kΩ
1%
52.3kΩ
1%
20kΩ
1%
20kΩ
1%
20kΩ
1%
1
MAX4230
5
3
4
47Ω
2
10µF
6V
0.1µF ^+3.3V
1.47kΩ
1
MAX4230
5
3
4
47Ω
2
10µF
6V
0.1µF ^+3.3V
1.47kΩ
1
MAX4230
5
3
4
47Ω
2
10µF
6V
2.413V
330µF
6V
1.647V
330µF
6V
0.880V
330µF
6V
1.47kΩ
*PLACE THE 1µF REFP-TO-REFN BYPASS CAPACITOR AS CLOSE TO THE DEVICE AS POSSIBLE.
0.1µF
+3.3V
2.2µF
0.1µF
10µF
1µF*
0.1µF
1
REFP
V_DD
REFOUT ³⁸
2 ^MAX12553
REFN
0.1µF
3 _COM
2.2µF
39
REFIN
GND
0.1µF
+3.3V
2.2µF
0.1µF
10µF
1µF*
0.1µF
1 _REFP
V_DD
REFOUT ³⁸
MAX12553
2
REFN
0.1µF
3 _COM
2.2µF
39
REFIN
GND
Figure 14. External Unbuffered Reference Driving Multiple ADCs
Unbuffered External
Reference Drives Multiple ADCs
The unbuffered external reference mode allows for pre-
cise control over the MAX12553 reference and allows
multiple converters to use a common reference.
Connecting REFIN to GND disables the internal refer-
ence, allowing REFP, REFN, and COM to be driven
directly by a set of external reference sources.
Figure 14 uses the MAX6029EUK30 precision 3.000V
reference as a common reference for multiple convert-
ers. A seven-component resistive divider chain follows
the MAX6029 voltage reference. The 0.47µF capacitor
along this chain creates a 10Hz lowpass filter. Three
MAX4230 operational amplifiers buffer taps along this
resistor chain providing 2.413V, 1.647V, and 0.880V to
the MAX12553’s REFP, COM, REFN reference inputs,
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