PWM Controller and Transformer Driver
with Quad-Channel Isolators
ADuM3470/ADuM3471/ADuM3472/ADuM3473/ADuM3474
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
T1
Isolated PWM controller
V
V
CC
RECT
ISO
Integrated transformer driver
Regulated adjustable output: 3.3 V to 24 V
2 W output power
70% efficiency at guaranteed load of 400 mA at 5.0 V output
Quad dc-to-25 Mbps (NRZ) signal isolation channels
20-lead SSOP package
V
REG
X1
X2
ADuM3470/ADuM3471/
ADuM3472/ADuM3473/
ADuM3474
V
DD2
V
REG
DD1
5V
CONVERTER
PRIMARY
DRIVER
FB
SECONDARY
CONTROLLER
FB
OC
High temperature operation: 105°C
High common-mode transient immunity: >25 kV/μs
200 kHz to 1 MHz adjustable oscillator frequency
Soft start function at power-up
Pulse-by-pulse overcurrent protection
Thermal shutdown
CHA
CHB
CHC
CHD
V
DDA
I/OA
I/OB
I/OC
I/OD
I/OA
I/OB
I/OC
I/OD
PRIMARY
DATA
I/O
SECONDARY
DATA
I/O
4CH
4CH
2500 V rms isolation
GND
GND
2
1
APPLICATIONS
Figure 1. Functional Block Diagram
ADuM3470 ADuM3471
RS-232/RS-422/RS-485 transceivers
Industrial field bus isolation
Power supply startup bias and gate drives
Isolated sensor interfaces
Process controls
GENERAL DESCRIPTION
The ADuM3470/ADuM3471/ADuM3472/ADuM3473/ADuM3474
devices1 are quad-channel, digital isolators with an integrated
PWM controller and transformer driver for an isolated dc-to-dc
converter. Based on the Analog Devices, Inc., iCoupler® technology,
the dc-to-dc converter provides up to 2 W of regulated, isolated
power at 3.3 V to 24 V from a 5.0 V input supply or from a 3.3 V
supply. This eliminates the need for a separate, isolated dc-to-dc
converter in 2 W isolated designs. The iCoupler chip-scale
transformer technology is used to isolate the logic signals, and the
integrated transformer driver with isolated secondary side control
provides higher efficiency for the isolated dc-to-dc converter.
The result is a small form factor, total isolation solution.
ADuM3472
ADuM3473
ADuM3474
The ADuM347x isolators provide four independent isolation
channels in a variety of channel configurations and data rates.
(The x in ADuM347x throughout this data sheet stands for the
ADuM3470/ADuM3471/ADuM3472/ADuM3473/ADuM3474.)
Figure 2. Block Diagrams of I/O Channels
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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