MAX1192 Maxim, MAX1192 Datasheet - Page 22

• Manufacturer Part Number: MAX1192
• Description: Ultra-Low-Power / 22Msps / Dual 8-Bit ADC
• Manufacturer: Maxim

Ultra-Low-Power, 22Msps, Dual 8-Bit ADC
Figure 10. External Buffered (MAX4250) Reference Drive Using a MAX6062 Bandgap Reference
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.
22
NOTE: ONE FRONT-END REFERENCE
CIRCUIT PROVIDES ±15mA OF OUTPUT
DRIVE AND SUPPORTS OVER
1000 MAX1192s.
0.1µF
______________________________________________________________________________________
3V
MAX6061
1
3
2
1µF
LOWPASS
1.248V
FILTER
10Hz
3
4
MAX4250
1%
20kΩ
1%
90.9kΩ
5
2
3V
1
0.1µF
15Ω
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.
Unbuffered External Reference Drives
0.33µF
0.33µF
0.33µF
0.33µF
0.33µF
0.33µF
0.1µF
0.1µF
1.023V
24
27
26
25
24
27
26
25
REFIN
REFP
REFN
COM
REFIN
REFP
REFN
COM
MAX1192
MAX1192
N = 1000
N = 1
GND
GND
V
V
DD
DD
0.1µF
Multiple ADCs
2.2µF