UG-042 Datasheet, PDF (3/8 Pages) Analog Devices – Evaluating the 16-Lead SOIC and the 16-Lead QSOP Digital Isolators

EVAL-ADuMQSEBZ User Guide
EVALUATION BOARD HARDWARE
PAD LAYOUT FOR THE DEVICE UNDER TEST (DUT)
The evaluation board has a pad layout in U2A that accommodates
16-lead, wide-body SOIC devices, as well as QSOP miniature
packages, as shown in Figure 2. Power and ground connections
connect to capacitor pads for Side 1 and Side 2.
UG-042
(but not populated) to connect the ADuM5000 in master or slave
mode, as well as to set the output voltage. See the ADuM5000
data sheet for descriptions of the pin functions.
Figure 2. DUT Pad Layout Component U2A
Three low inductance, surface-mount bypass capacitors are
provided for each side. A 100 nF capacitor is installed on each
side in Capacitor C2 and Capacitor C3. Additional bypass
capacitors are required for QSOP packages and are below the
QSOP pads and within the pad layout of the SOIC package.
However, they cannot be installed if the SOIC is in use.
In addition, there are 10 µF ceramic, X7R capacitors, C1 on Side 1
and C4 on Side 2, that provide high frequency bypassing and
ripple reduction. For further ripple reduction in isoPower®
devices like the ADuM540x, tantalum capacitors are added to
C10 as a 68 µF value on Side 1 and to C5 as a 22 µF value on
Side 2. These large value ceramic and tantalum bypass capacitors
are not necessary for non-isoPower devices.
Many of the iCoupler devices have configuration pins that allow
outputs to be disabled or default levels to be set. These pins are
usually located at Pin 7 and Pin 10 in the wide body package. Pull-
up 0 Ω resistors on SM Pad R4 and SM Pad R17 pull these pins
high. These pull-up resistors can be removed, and pull-down
resistors can be installed on R5 and R18.
In addition to the U2A DUT space, an additional pad layout is
provided at U1, specifically to accommodate an ADuM5000
isoPower device, as shown in Figure 3, which is a power supply
only device that can provide secondary power for any iCoupler
in standalone mode or a slave to boost power to the ADuM520x
or ADuM540x devices. The surface-mount resistor pads that
control these functions are not populated.
An ADuM5000 is not installed at Position U1; it is left to the
user to obtain and install this device, if required. As shown in
Figure 3, the power and ground connections for this device are
different from the rest of the iCoupler components. The C6 to
C9 pad positions for bypass capacitors are provided but not
populated (0.1 µF, X7R, ceramic capacitors are recommended).
Pull-up, pull-down, and connecting resistor pads are provided
Figure 3. ADuM5000 Pad Layout Component U1
Grounding Scheme
The evaluation board consists of two separate ground and
power systems. Each side of the DUT can operate from an
independent power and ground reference, which allows
simulation of conditions similar to the target application. The
evaluation board provides for board creepage and clearance
typical of most 2.5 kV circuit boards. It is not recommended for
use above 2.5 kV rms transient voltages or for isolation voltage
testing above 2500 V rms.
Electromagnetic Interference (EMI) and Electromagnetic
Compatibility (EMC) Measurements
The signal path was made as simple as possible while still
providing flexibility. The evaluation board is not intended for
detailed characterization of system noise, EMI, or EMC. It may
be useful for initial bench work in these areas, but Analog Devices,
Inc., does not guarantee that the evaluation board results will be
indicative of the final system performance in these areas. The
evaluation board includes some of the structures discussed in
the AN-0971 Application Note for radiated EMI mitigation.
TERMINALS
Side 1 Power Supply Inputs
Power is supplied to the evaluation board via a set of terminal
block connectors, IO_1C, as shown in Figure 4. Power is connected
to the Pin 1 top terminal, and ground is connected to the Pin 2
top terminal. Provisions for adding in-line inductors for noise
isolation were made with the inclusion of Z1 and Z2, which are
1206 size, surface-mount components. These positions are
populated with 0 Ω resistors to connect power to the evaluation
board. If ferrite inductors are required for noise control, remove
these components and replaced them with appropriate inductors.
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