MAX1197ECM+TD Maxim Integrated Products, MAX1197ECM+TD Datasheet - Page 18

• Manufacturer Part Number: MAX1197ECM+TD
• Description: IC ADC 8BIT 60MSPS DL 48-TQFP
• Manufacturer: Maxim Integrated Products

Specifications of MAX1197ECM+TD

• Number Of Bits: 8
• Sampling Rate (per Second): 60M
• Data Interface: Parallel
• Number Of Converters: 2
• Power Dissipation (max): 150mW
• 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
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 9. External Unbuffered Reference Drive with MAX4252 and MAX6066
Dual, 8-Bit, 60Msps, 3V, Low-Power ADC with
Internal Reference and Parallel Outputs
modulation (QAM). Typically found in spread-spectrum-
based systems, a QAM signal represents a carrier fre-
quency modulated in both amplitude and phase. At the
transmitter, modulating the baseband signal with quad-
rature outputs, a local oscillator followed by subse-
quent upconversion can generate the QAM signal. The
result is an in-phase (I) and a quadrature (Q) carrier
component, where the Q component is 90° phase shift-
ed with respect to the in-phase component. At the
receiver, the QAM signal is divided down into its I and
Q components, essentially representing the modulation
process reversed. Figure 10 displays the demodulation
process performed in the analog domain, using the
dual matched 3V, 8-bit ADC MAX1197 and the
MAX2451 quadrature demodulator to recover and digi-
18
MAX4254 POWER SUPPLY
BYPASSING. PLACE CAPACITOR
AS CLOSE AS POSSIBLE TO
THE OP AMP.
NOTE: ONE FRONT-END REFERENCE CIRCUIT DESIGN MAY BE USED WITH UP TO 32 ADCs.
3.3V
______________________________________________________________________________________
MAX6066
1
3
0.1µF
3.3V
2
21.5kΩ
0.1µF
1µF
21.5kΩ
21.5kΩ
21.5kΩ
21.5kΩ
2.0V
1.5V
1.0V
10
3
2
5
6
9
4
4
4
11
11
11
1/4 MAX4252
1/4 MAX4252
1/4 MAX4252
3.3V
3.3V
3.3V
1
7
8
10µF
6V
10µF
6V
10µF
6V
1.47kΩ
1.47kΩ
1.47kΩ
47kΩ
47kΩ
47kΩ
1.0V AT -8mA
2.0V AT 8mA
1.5V AT 0mA
tize the I and Q baseband signals. Before being digi-
tized by the MAX1197, the mixed-down signal compo-
nents may be filtered by matched analog filters, such
as Nyquist or pulse-shaping filters which remove
unwanted images from the mixing process, thereby
enhancing the overall signal-to-noise (SNR) perfor-
mance and minimizing intersymbol interference.
The MAX1197 requires high-speed board layout design
techniques. Locate all bypass capacitors as close to
the device as possible, preferably on the same side as
the ADC, using surface-mount devices for minimum
330µF
6V
330µF
330µF
6V
6V
0.1µF
0.1µF
N.C.
N.C.
0.1µF
0.1µF
Grounding, Bypassing,
0.1µF
0.1µF
and Board Layout
29
31
32
29
31
32
1
2
1
2
REFOUT
REFIN
REFP
REFN
COM
REFOUT
REFIN
REFP
REFN
COM
MAX1197
MAX1197
N = 32
N = 1
0.1µF
2.2µF
10V