Isolated Switching Regulator

With Integrated Feedback

Data Sheet

ADuM3070

Rev. 0

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FEATURES

Isolated PWM feedback with built in compensation

Primary side transformer driver for up to 2.5 W output power

with 5 V input voltage

Regulated adjustable output: 3.3 V to 24 V

Up to 80% efficiency

200 kHz to 1 MHz adjustable oscillator

Soft start function at power-up

Pulse-by-pulse overcurrent protection

Thermal shutdown

2500 V rms isolation

High common-mode transient immunity: >25 kV/µs

16-lead QSOP package

High temperature operation: 105°C

APPLICATIONS

Power supply startup bias and gate drives

Isolated sensor interfaces

Process controls

FUNCTIONAL BLOCK DIAGRAM

Figure 1.

GENERAL DESCRIPTION

The ADuM30701 isolator is a regulated dc-to-dc isolated power

supply controller with 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 ADuM3070 isolator provides 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 small QSOP package provides a smaller form factor than any

discrete solution. The regulated feedback provides a relatively flat

efficiency curve over the full output power range. The ADuM3070

enables 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.

1

Protected by U.S. Patents 5,952,849; 6,873,065; and 7075 329 B2. Other patents are pending.

ADuM3070

PRIMARY

CONVERTER/

DRIVER

SECONDARY

CONTROLLER

INTERNAL

FEEDBACK

OC

FB

X2

X1

REG

RECT

5V

NOTES