Datasheet

MAX1192
Ultra-Low-Power, 22Msps, Dual 8-Bit ADC
22 ______________________________________________________________________________________
Figure
10 shows the MAX6061 precision bandgap ref-
erence used as a common reference for multiple con-
verters. The 1.248V output of the MAX6061 is divided
down to 1.023V as it passes through a one-pole, 10Hz,
lowpass filter to the MAX4250. The MAX4250 buffers
the 1.023V reference before its output is applied to the
MAX1192. The MAX4250 provides a low offset voltage
(for high gain accuracy) and a low noise level.
Unbuffered External Reference Drives
Multiple ADCs
The unbuffered external reference mode allows for pre-
cise control over the MAX1192 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.
MAX4250
3V
2
4
2
1.248V
3
5
10Hz
LOWPASS
FILTER
1
15Ω
1
REFIN
V
DD
MAX1192
N = 1
24
GND
1.023V
NOTE: ONE FRONT-END REFERENCE
CIRCUIT PROVIDES ±15mA OF OUTPUT
DRIVE AND SUPPORTS OVER
1000 MAX1192s.
3
0.1μF
0.1μF
3V
1μF
1%
20kΩ
1%
90.9kΩ
0.1μF
2.2μF
0.1μF
REFP
27
0.33μF
REFN
26
0.33μF
COM
25
0.33μF
REFIN
V
DD
MAX1192
N = 1000
24
GND
0.1μF
REFP
27
0.33μF
REFN
26
0.33μF
COM
25
0.33μF
MAX6061
Figure 10. External Buffered (MAX4250) Reference Drive Using a MAX6062 Bandgap Reference