AD7400AYRWZ-RL Analog Devices Inc, AD7400AYRWZ-RL Datasheet - Page 17

• Manufacturer Part Number: AD7400AYRWZ-RL
• Description: Isolated Sigma-Delta Modulator ADC I.C.
• Manufacturer: Analog Devices Inc
• Type: Modulatorr

Specifications of AD7400AYRWZ-RL

• Resolution (bits): 14 b
• Data Interface: Serial
• Voltage Supply Source: Single Supply
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sampling Rate (per Second): -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
GROUNDING AND LAYOUT
Supply decoupling with a value of 100 nF is strongly recom-
mended on both V
both V
applications involving high common-mode transients, ensure
that board coupling across the isolation barrier is minimized.
Furthermore, the board layout should be designed so that
any coupling that occurs equally affects all pins on a given
component side. Failure to ensure this may cause voltage
differentials between pins to exceed the absolute maximum
ratings of the device, thereby leading to latch-up or permanent
damage. Any decoupling used should be placed as close to the
supply pins as possible.
Series resistance in the analog inputs should be minimized to
avoid any distortion effects, especially at high temperatures. If
possible, equalize the source impedance on each analog input to
minimize offset. Beware of mismatch and thermocouple effects
on the analog input PCB tracks to reduce offset drift.
EVALUATING THE AD7400A PERFORMANCE
An AD7400A evaluation board is available with split ground
planes and a board split beneath the AD7400A package to
ensure isolation. This board allows access to each pin on the
device for evaluation purposes.
The evaluation board package includes a fully assembled and
tested evaluation board, documentation, and software for
controlling the board from the PC via the EVAL-CED1Z. The
software also includes a SINC
The evaluation board is used in conjunction with the EVAL-CED1Z
board and can be used as a standalone board. The software
allows the user to perform ac (fast Fourier transform) and dc
(histogram of codes) tests on the AD7400A. The software and
documentation are on a CD that ships with the evaluation board.
DDx
pins does not significantly affect performance. In
DD1
and V
DD2
3
filter implemented on an FPGA.
. Decoupling on one or
Rev. B | Page 17 of 20
INSULATION LIFETIME
All insulation structures subjected to sufficient time and/or
voltage are vulnerable to breakdown. In addition to the testing
performed by the regulatory agencies, Analog Devices has carried
out an extensive set of evaluations to determine the lifetime of
the insulation structure within the AD7400A.
These tests subjected populations of devices to continuous
cross-isolation voltages. To accelerate the occurrence of failures,
the selected test voltages were values exceeding those of normal
use. The time to failure values of these units were recorded and
used to calculate acceleration factors. These factors were then
used to calculate the time to failure under normal operating
conditions. The values shown in Table 7 are the lesser of the
following two values:
•
•
Note that the lifetime of the AD7400A varies according to
the waveform type imposed across the isolation barrier. The
iCoupler insulation structure is stressed differently depending
on whether the waveform is bipolar ac, unipolar ac, or dc.
Figure 29, Figure 30, and Figure 31 illustrate the different
isolation voltage waveforms.
The value that ensures at least a 50-year lifetime of
continuous use.
The maximum CSA/VDE approved working voltage.
RATED PEAK VOLTAGE
RATED PEAK VOLTAGE
RATED PEAK VOLTAGE
0V
0V
0V
Figure 30. Unipolar AC Waveform
Figure 29. Bipolar AC Waveform
Figure 31. DC Waveform
AD7400A