PWM Controller and Transformer Driver

with Quad-Channel Isolators

ADuM3470/ADuM3471/ADuM3472/ADuM3473/ADuM3474

Rev. 0

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FEATURES

Isolated PWM controller

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

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

2500 V rms isolation

APPLICATIONS

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.

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.)

FUNCTIONAL BLOCK DIAGRAMS

ADuM3470/ADuM3471/

ADuM3472/ADuM3473/

ADuM3474

CONVERTER

PRIMARY

DRIVER

PRIMARY

DATA

I/O

4CH

SECONDARY

DATA

I/O

4CH

SECONDARY

CONTROLLER

CHA

FB

T1

CHB

CHC

CHD

OC

FB

I/OA

X2

X1

I/OB

I/OC

I/OD

I/OA

I/OB

I/OC

I/OD

REG

RECT

5V

Figure 1. Functional Block Diagram

ADuM3470

ADuM3471

ADuM3472

ADuM3473

ADuM3474

Figure 2. Block Diagrams of I/O Channels