Isolated Switching Regulator
with Quad-Channel Isolators
Data Sheet
ADuM4470/ADuM4471/ADuM4472/ADuM4473/ADuM4474
FUNCTIONAL BLOCK DIAGRAM
FEATURES
V
ISO
V
DD1
Isolated PWM feedback with built in compensation
Primary side transformer driver for up to 2.5 W output power
with 5 V input voltage
RECT
V
REG
ADuM4470/
ADuM4471/
ADuM4472/
ADuM4473/
ADuM4474
Regulated adjustable output: 3.3 V to 24 V
Up to 80% efficiency
Quad dc-to-25 Mbps (NRZ) signal isolation channels
200 kHz to 1 MHz adjustable oscillator
Soft start function at power-up
Pulse-by-pulse overcurrent protection
Thermal shutdown
5000 V rms isolation
V
DD2
REG
5V
PRIMARY
CONTROLLER/
DRIVER
V
DDA
SECONDARY
FB
CONTROLLER
INTERNAL
FEEDBACK
OC
I/OA
I/OA
I/OB
I/OC
I/OD
CHA
CHB
CHC
CHD
I/OB
I/OC
I/OD
PRIMARY
DATA I/O
4-CHANNEL
SECONDARY
DATA I/O
4-CHANNEL
High common-mode transient immunity: >25 kV/μs
20-lead SOIC package with 8.3 mm creepage
High temperature operation: 105°C
APPLICATIONS
GND
GND
2
1
Power supply start-up bias and gate drives
Isolated sensor interfaces
Figure 1.
Process controls
RS-232/RS-422/RS-485 transceivers
GENERAL DESCRIPTION
The ADuM4470/ADuM4471/ADuM4472/ADuM4473/
ADuM44741 are quad-channel, digital isolators with a regu-
lated dc-to-dc isolated power supply controller and an internal
MOSFET driver. The dc-to-dc controller has an internal isolated
PWM feedback from the secondary side, based on the
iCoupler® chip scale transformer technology and complete loop
compensation. This eliminates the need to use an optocoupler
for feedback and compensates the loop for stability.
The regulated feedback provides a relatively flat efficiency curve
over the full output power range. The ADuM447x enable a dc-
to-dc converter with a 3.3 V to 24 V isolated output voltage
range from either a 5.0 V or a 3.3 V input voltage, with an
output power of up to 2.5 W.
The ADuM447x isolators provide four independent isolation
channels in a variety of channel configurations and data rates.
(The x in ADuM447x throughout this data sheet stands for the
ADuM4470/ADuM4471/ADuM4472/ADuM4473/ADuM4474.)
The ADuM447x isolators provide a more stable output voltage
and higher efficiency compared to unregulated isolated dc-
to-dc power supplies. The fully integrated feedback and loop
compensation in a wide-body SOIC package provide a smaller
form factor and 8.3 mm creepage distance solution.
1 Protected by U.S. Patents 5,952,849; 6,873,065; and 7075 329 B2. Other patents pending.
Rev. 0
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