MAX1198ECM+D Maxim Integrated Products, MAX1198ECM+D Datasheet - Page 16

• Manufacturer Part Number: MAX1198ECM+D
• Description: IC ADC 8BIT 100MSPS DUAL 48-TQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1198ECM+D

• Number Of Bits: 8
• Sampling Rate (per Second): 100M
• Data Interface: Parallel
• Number Of Converters: 2
• Power Dissipation (max): 314mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 48-TQFP Exposed Pad, 48-eTQFP, 48-HTQFP, 48-VQFP
• Conversion Rate: 100 MSPs
• Resolution: 8 bit
• Snr: 48.5 dB
• Voltage Reference: 2.048 V
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 2.7 V
• Maximum Power Dissipation: 1000 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Input Voltage: 3.3 V
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 6. Transformer-Coupled Input Drive
Dual, 8-Bit, 100Msps, 3.3V, Low-Power ADC
with Internal Reference and Parallel Outputs
requirements. A reduced signal swing from the input
driver, such as an op amp, can also improve the overall
distortion.
In general, the MAX1198 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.
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.
16
V
V
IN
IN
______________________________________________________________________________________
0.1µF
0.1µF
Single-Ended AC-Coupled Input Signal
N.C.
N.C.
MINICIRCUITS
MINICIRCUITS
3
3
1
2
TT1–6-KK81
1
2
TT1-6-KK81
T1
T1
6
5
4
6
5
4
2.2µF
2.2µF
25Ω
25Ω
25Ω
25Ω
0.1µF
0.1µF
22pF
22pF
22pF
22pF
INA+
COM
INA-
INB+
INB-
MAX1198
Figure 7. Using an Op Amp for Single-Ended, AC-Coupled
Input Drive
Multiple-converter systems based on the MAX1198 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 1-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
produced in the voltage reference and buffer stages.
This filtered noise density, which decreases for higher
frequencies, meets the noise levels specified for preci-
sion ADC operation.
V
V
IN
IN
MAX4108
MAX4108
Buffered External Reference Drives
100Ω
100Ω
100Ω
100Ω
0.1µF
0.1µF
REFP
REFN
REFP
REFN
1kΩ
1kΩ
1kΩ
1kΩ
0.1µF
0.1µF
R
50Ω
R
50Ω
ISO
ISO
22pF
22pF
50Ω
50Ω
R
R
C
C
C
22pF
C
22pF
ISO
ISO
IN
IN
IN
IN
Multiple ADCs
INA+
COM
INA-
INB+
INB-
MAX1198