ADUM5000ARWZ-RL Analog Devices Inc, ADUM5000ARWZ-RL Datasheet - Page 12

• Manufacturer Part Number: ADUM5000ARWZ-RL
• Description: Isolated DC/DC Converter
• Manufacturer: Analog Devices Inc
• Series: IsoPower®, iCoupler®r

Specifications of ADUM5000ARWZ-RL

• Design Resources: USB Cable Isolator Circuit (CN0159)
• Inputs - Side 1/side 2: 2/0
• Number Of Channels: 2
• Isolation Rating: 2500Vrms
• Voltage - Supply: 2.7 V ~ 5.5 V
• 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
• Data Rate: -
• Propagation Delay: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADuM5000
When starting the device for V
the current available to the V
The ADuM5000 may not be able to drive the output to the
regulation point if a current limiting device clamps the V
voltage during startup. As a result, the ADuM5000 can draw
large amounts of current at low voltage for extended periods.
The output voltage of the ADuM5000 device exhibits V
shoot during startup. If this could potentially damage components
attached to V
diode, can be used to clamp the voltage. Typical behavior is
shown in Figure 12 and Figure 13.
EMI CONSIDERATIONS
It is necessary for the dc-to-dc converter section of the ADuM5000
to operate at 180 MHz 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 input and output
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 the
recommendations..
THERMAL ANALYSIS
The ADuM5000 consists of four internal silicon die, attached to
a split lead frame with two die attach paddles. For the purposes
of thermal analysis, it is treated as a thermal unit with the highest
junction temperature reflected in the θ
of θ
on a JEDEC standard 4-layer board with fine width traces and
still air. Under normal operating conditions, the ADuM5000
operates at full load across the full temperature range without
derating the output current. However, following the recommen-
dations in the PCB Layout section decreases the thermal resistance
to the PCB allowing increased thermal margin at high ambient
temperatures.
CURRENT LIMIT AND THERMAL OVERLOAD
PROTECTION
The ADuM5000 is protected against damage due to excessive
power dissipation by thermal overload protection circuits. Thermal
overload protection limits the junction temperature to a maximum
of 150°C (typical). Under extreme conditions (that is, high ambient
temperature and power dissipation), when the junction temperature
starts to rise above 150°C, the PWM is turned off, which turns
off the output current. When the junction temperature drops
below 130°C (typical), the PWM turns on again, restoring the
output current to its nominal value.
JA
is based on measurements taken with the part mounted
ISO
, then a voltage-limiting device, such as a Zener
AN-0971 Application Note
DD1
ISO
power pin to less than 300 mA.
= 5 V operation, do not limit
JA
from Table 5. The value
for board layout
ISO
DD1
over-
Rev. A | Page 12 of 16
Consider the case where a hard short from V
At first, the ADuM5000 reaches its maximum current, which is
proportional to the voltage applied at V
the primary side of the converter (see Figure 7). If self-heating of
the junction becomes great enough to cause its temperature to rise
above 150°C, thermal shutdown activates, turning off the PWM
and turning off the output current. As the junction temperature
cools and drops below 130°C, the PWM turns on and power
dissipates again on the primary side of the converter, causing
the junction temperature to rise to 150°C again. This thermal
oscillation between 130°C and 150°C causes the part to cycle
on and off as long as the short remains at the output.
Thermal limit protections are intended to protect the device
against accidental overload conditions. For reliable operation,
externally limit device power dissipation to prevent junction
temperatures from exceeding 130°C.
POWER CONSIDERATIONS
The ADuM5000 converter primary side is protected from premature
operation by undervoltage lockout (UVLO) circuitry. Below the
minimum operating voltage, the power converter holds its
oscillator inactive.
When the primary side oscillator begins to operate, it transfers
power to the secondary power circuits. The secondary V
starts below its UVLO limit making it inactive and unable to
generate a regulation control signal. The primary side power
oscillator is allowed to free run under this condition, supplying
the maximum amount of power to the secondary side.
As the secondary side voltage rises to its regulation setpoint,
a large inrush current transient is present at V
regulation point is reached, the regulation control circuit produces
the regulation control signal that modulates the oscillator on the
primary side. The V
to the load current. The inrush current is less than the short-
circuit current shown in Figure 7. The duration of the inrush
depends on the V
voltage available at the V
INCREASING AVAILABLE POWER
The ADuM5000 device is designed to work in combination with
other compatible isoPower devices. The RC
pins allow the ADuM5000 to provide its PWM signal to another
device through the RC
receive a PWM signal from another device through its RC
and act as a slave to that control signal. The RC
whether the part acts as a master or slave device.
When the ADuM5000 is acting as a slave, its power is regulated
by the master device allowing multiple isoPower parts to be
combined in parallel while sharing the load equally. When the
ADuM5000 is configured as a master or standalone unit, it
generates its own PWM feedback signal to regulate itself and
slave devices.
ISO
DD1
loading conditions and on the current and
current is then reduced and is proportional
OUT
DD1
pin acting as a master. It can also
pin.
DD1
OUT
. Power dissipates on
ISO
, RC
to ground occurs.
DD1
SEL
. When the
IN
pin chooses
, and RC
ISO
voltage
IN
SEL
pin