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MAX1196 Datasheet, PDF (17/23 Pages) Maxim Integrated Products – Dual 8-Bit, 40Msps, 3V, Low-Power ADC with Internal Reference and Multiplexed Parallel Outputs
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Dual 8-Bit, 40Msps, 3V, Low-Power ADC with
Internal Reference and Multiplexed Parallel Outputs
In general, the MAX1196 provides better SFDR and
THD with fully differential input signals than single-
ended drive, especially for very high input frequencies.
In differential input mode, even-order harmonics are
lower as both inputs (INA+, INA- and/or INB+, INB-) are
balanced, and each of the ADC inputs only requires
half the signal swing compared to single-ended mode.
Single-Ended AC-Coupled Input Signal
Figure 7 shows an AC-coupled, single-ended applica-
tion. Amplifiers like the MAX4108 provide high speed,
high bandwidth, low noise, and low distortion to main-
tain the integrity of the input signal.
Buffered External Reference Drives
Multiple ADCs
Multiple-converter systems based on the MAX1196 are
well suited for use with a common reference voltage.
The REFIN pin of those converters can be connected
directly to an external reference source.
A precision bandgap reference like the MAX6062 gen-
erates an external DC level of 2.048V (Figure 8), and
exhibits a noise voltage density of 150nV/√Hz. Its out-
put passes through a one-pole lowpass filter (with 10Hz
cutoff frequency) to the MAX4250, which buffers the
reference before its output is applied to a second 10Hz
lowpass filter. The MAX4250 provides a low offset volt-
age (for high gain accuracy) and a low noise level. The
passive 10Hz filter following the buffer attenuates noise
25Ω
22pF
0.1µF
VIN
1 T1 6
N.C. 2
5
2.2µF 0.1µF
3
4
MINICIRCUITS
TT1-6-KK81
25Ω
22pF
25Ω
22pF
0.1µF
VIN
1 T1 6
N.C. 2
5
2.2µF 0.1µF
3
4
MINICIRCUITS
TT1-6-KK81
25Ω
22pF
INA+
COM
INA-
MAX1196
INB+
INB-
REFP
VIN
MAX4108
100Ω
0.1µF
1kΩ RISO
50Ω
CIN
1kΩ
22pF
100Ω
REFN
REFP
0.1µF
RISO
50Ω
CIN
22pF
VIN
0.1µF
MAX4108
100Ω
1kΩ RISO
50Ω
CIN
1kΩ
22pF
100Ω
REFN
0.1µF
RISO
50Ω
CIN
22pF
INA+
COM
INA-
MAX1196
INB+
INB-
Figure 6. Transformer-Coupled Input Drive
Figure 7. Using an Op Amp for Single-Ended, AC-Coupled
Input Drive
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