MAX11040KGUU+T Maxim Integrated, MAX11040KGUU+T Datasheet - Page 13

• Manufacturer Part Number: MAX11040KGUU+T
• Description: Analog to Digital Converters - ADC 24Bit 4Ch Simul-Samp Cascadable Sig Delt
• Manufacturer: Maxim Integrated

Specifications of MAX11040KGUU+T

• Rohs: yes
• Number Of Channels: 4
• Architecture: Sigma-Delta
• Conversion Rate: 64 KSPs
• Resolution: 24 bit
• Input Type: Differential
• Snr: 106 dB, 117 dB
• Interface Type: 4-Wire (SPI, Microwire), QSPI
• Operating Supply Voltage: 2.7 V to 3.6 V, 3 V to 3.6 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• Maximum Power Dissipation: 1096 mW
• Minimum Operating Temperature: - 40 C
• Number Of Converters: 4
• Voltage Reference: Internal 2.2 V

Table 1. Bandwidth vs. Output Data Rate
The devices contain an on-chip digital lowpass filter
that processes the data stream from each modulator
and generates the high-resolution output data. The low-
pass filter frequency response is determined by the
programmable output data rate. At the nominal 16ksps
output data rate, the -3dB bandwidth of the filter is
3.4kHz. The passband flatness is better than ±0.1dB
from 0 to 1.74kHz. The notches are located at 5.75kHz
and 7.195kHz. These frequencies scale linearly with the
output data rate. See Figure 2 and Table 1 for the fre-
quency response at different data rates.
Figure 2. Digital Filter Response
Maxim Integrated
OUTPUT DATA
RATE (ksps)
0.5
10
12
16
32
64
1
2
4
8
-1
-2
-3
-4
-5
-6
1
0
0
24-/16-Bit, 4-Channel, Simultaneous-Sampling,
-3dB BANDWIDTH
0.04
0.08
(kHz)
0.11
0.21
0.42
0.85
1.69
2.11
2.54
3.38
6.78
13.5
f
0.12
AIN
/f
SAMPLE
0.16
0.20
-0.1dB BANDWIDTH
0.24
Digital Filter
0.28
(kHz)
0.05
0.11
0.22
0.43
0.87
1.09
1.31
1.74
3.48
6.96
Cascadable, Sigma-Delta ADCs
MAX11040K/MAX11060
Since the transfer function of a digital filter is repeatable
and predictable, it is possible to correct for frequency-
dependent attenuation in downstream software. See
the Compensating for the Rolloff of the Digital Filter in a
Typical FFT Analysis section. The transfer function is
defined by the following equation:
where:
Gain is the filter gain.
f
f
16kHz.
f
24.576MHz.
FIR_Gain (f
with the following filter coefficients, as a function of the
analog input frequency f
applied at the output data rate:
AIN
SAMPLE
XINCLOCK
Gain f
+ 0.022
- 0.074
- 0.036
+ 0.312
+ 0.552
+ 0.312
- 0.036
- 0.074
+ 0.022
is the analog input frequency.
(
AIN
is the programmed output data rate, nominally
)
=
AIN
×
is the clock frequency at XIN, nominally
⎛
⎜
⎜
⎜
⎜
⎜
⎝
f
(
X X INCLOCK
FIR Gain f
) is the normalized gain of the FIR filter
f
SAMPLE
_
(
×
×
AIN
sin π
sin
AIN
)
)
⎛
⎜
⎝
⎛
⎜
⎝
. These coefficients are
π
×
×
f
f
SAMPLE
XINCLOCK
f
AIN
f
AIN
⎞
⎟
⎠
⎞
⎟
⎠
⎞
⎟
⎟
⎟
⎟
⎟
⎠ ⎠
3
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