ADUM5400ARWZ-RL Analog Devices Inc, ADUM5400ARWZ-RL Datasheet - Page 12

• Manufacturer Part Number: ADUM5400ARWZ-RL
• Description: QUAD-CHANNEL DIGITAL ISOLATORS
• Manufacturer: Analog Devices Inc
• Series: IsoPower®, iCoupler®r

Specifications of ADUM5400ARWZ-RL

• Inputs - Side 1/side 2: 4/0
• Number Of Channels: 4
• Isolation Rating: 2500Vrms
• Voltage - Supply: 3.35V, 4.1V, 5V
• Data Rate: 1Mbps
• Propagation Delay: 55ns
• Output Type: Logic
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Operating Temperature: -40°C ~ 105°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: EVAL-ADUM540XEBZ - BOARD EVAL FOR ADUM540x
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADuM5400
APPLICATIONS INFORMATION
The dc-to-dc converter section of the ADuM5400 works on
principles that are common to most modern power supplies. It
has a secondary side controller architecture with isolated pulse-
width modulation (PWM) feedback. V
an oscillating circuit that switches current into a chip scale air
core transformer. Power transferred to the secondary side is
rectified and regulated to 5 V. The secondary (V
controller regulates the output by creating a PWM control
signal that is sent to the primary (V
iCoupler data channel. The PWM modulates the oscillator
circuit to control the power being sent to the secondary side.
Feedback allows for significantly higher power and efficiency.
The ADuM5400 implements undervoltage lockout (UVLO)
with hysteresis on the V
feature ensures that the converter does not enter oscillation due
to noisy input power or slow power-on ramp rates.
A minimum load current of 10 mA is recommended to ensure
optimum load regulation. Smaller loads can generate excess noise
on chip due to short or erratic PWM pulses. Excess noise gener-
ated this way can cause data corruption in some circumstances.
PCB LAYOUT
The ADuM5400 digital isolator with integrated 0.5 W isoPower
dc-to-dc converter requires no external interface circuitry for
the logic interfaces. Power supply bypassing is required at the
input and output supply pins (see Figure 12). Note that a low
ESR bypass capacitor is required between Pin 1 and Pin 2,
within 2 mm of the chip leads.
The power supply section of the ADuM5400 uses a 180 MHz
oscillator frequency to efficiently pass power through its chip
scale transformers. In addition, normal operation of the data
section of the iCoupler introduces switching transients on the
power supply pins. Bypass capacitors are required and must
provide transient suppression at several operating frequencies.
Noise suppression requires a low inductance, high frequency
capacitor that is effective at 180 MHz and 360 MHz. Ripple
suppression and proper regulation require a large value capacitor
to provide bulk current at 625 kHz. These are most conveniently
connected between Pin 1 and Pin 2 for V
and Pin 16 for V
parallel combination of at least two capacitors is required. The
recommended capacitor values are 0.1 μF and 10 μF for V
The smaller capacitor must have low ESR; for example, use of a
ceramic capacitor is advised.
Note that the total lead length between the ends of the low ESR
capacitor and the input power supply pin must not exceed 2 mm.
Installing the bypass capacitor with traces more than 2 mm in
ISO
. To suppress noise and reduce ripple, a
DD1
, V
DDL
, and V
DD1
) side by a dedicated
DD1
ISO
DD1
power is supplied to
power supplies. This
and between Pin 15
ISO
) side
DD1
Rev. 0 | Page 12 of 16
.
length may result in data corruption. Consider a bypass capacitor
between Pin 1 and Pin 8 and between Pin 9 and Pin 16 unless
both common ground pins are connected together close to the
package.
In applications involving high common-mode transients, ensure
that board capacitive coupling across the isolation barrier is
minimized. Furthermore, design the board layout so that any
coupling that does occur affects all pins on a given component
side equally. Failure to ensure this can cause differential voltages
between pins, exceeding the absolute maximum ratings for the
device (specified in Table 7) and thereby leading to latch-up
and/or permanent damage.
The ADuM5400 is a power device that dissipates about 1 W
of power when fully loaded and running at maximum speed.
Because it is not possible to apply a heat sink to an isolation
device, the device depends primarily on heat dissipation into
the PCB through the GND pins. If the device is used at high
ambient temperatures, provide a thermal path from the GND pins
to the PCB ground plane. The board layout in Figure 12 shows
enlarged pads for Pin 8 (GND
diameter vias should be implemented from the pad to the
ground, and power planes should be used to reduce inductance.
Multiple vias in the thermal pads can significantly reduce temper-
atures inside the chip. The dimensions of the expanded pads are
at the discretion of the designer and depend on the available
board space.
EMI CONSIDERATIONS
The dc-to-dc converter section of the ADuM5400 components
must operate at a very high frequency to allow efficient power
transfer through the small transformers. This creates high
frequency currents that can propagate in circuit board ground
and power planes, causing edge emissions and dipole radiation
between the primary and secondary ground planes. Grounded
enclosures are recommended for applications that use these
devices. If grounded enclosures are not possible, follow good RF
design practices in the layout of the PCB. See www.analog.com
for the most current PCB layout recommendations specifically
for the ADuM5400.
BYPASS < 2mm
GND
GND
V
V
DD1
DDL
V
V
V
V
IB
IC
ID
IA
1
1
Figure 12. Recommended PCB Layout
ADuM5400
1
) and Pin 9 (GND
ISO
). Large
V
GND
V
V
V
V
V
GND
ISO
OA
OB
OC
OD
ISO
ISO
ISO