Isolated Switching Regulator With Integrated Feedback Data Sheet ADuM3070 FEATURES FUNCTIONAL BLOCK DIAGRAM V V DD1 ISO Isolated PWM feedback with built in compensation RECT Primary side transformer driver for up to 2.5 W output power X1 X2 V REG with 5 V input voltage ADuM3070 Regulated adjustable output: 3.3 V to 24 V V DD2 Up to 80% efficiency REG PRIMARY 5V 200 kHz to 1 MHz adjustable oscillator V CONVERTER/ DDA DRIVER SECONDARY FB Soft start function at power-up CONTROLLER INTERNAL OC FEEDBACK Pulse-by-pulse overcurrent protection GND GND Thermal shutdown 1 2 2500 V rms isolation NOTES High common-mode transient immunity: >25 kV/s 1. V IS THE POWER SUPPLY FOR THE PUSH-PULL TRANSFORMER. DD1 2. V IS THE POWER SUPPLY OF SIDE 1 OF THE ADuM3070. DDA 16-lead QSOP package High temperature operation: 105C Figure 1. APPLICATIONS Power supply startup bias and gate drives Isolated sensor interfaces Process controls GENERAL DESCRIPTION 1 The ADuM3070 isolator is a regulated dc-to-dc isolated power The ADuM3070 isolator provides a more stable output voltage and supply controller with an internal MOSFET driver. The dc-to- higher efficiency compared to unregulated isolated dc-to-dc power dc controller has an internal isolated PWM feedback from the supplies. The fully integrated feedback and loop compensation secondary side based on the iCoupler chip scale transformer in a small QSOP package provides a smaller form factor than any technology and complete loop compensation. This eliminates discrete solution. The regulated feedback provides a relatively flat the need to use an optocoupler for feedback and compensates efficiency curve over the full output power range. The ADuM3070 the loop for stability. 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. Rev. A Document Feedback Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 20122014 Analog Devices, Inc. All rights reserved. license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Technical Support www.analog.com Trademarks and registered trademarks are the property of their respective owners. 10437-001ADuM3070 Data Sheet TABLE OF CONTENTS Features .............................................................................................. 1 Pin Configuration and Function Descriptions ..............................8 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................9 Functional Block Diagram .............................................................. 1 Applications Information .............................................................. 14 General Description ......................................................................... 1 Application Schematics ............................................................. 14 Revision History ............................................................................... 2 Transformer Design ................................................................... 15 Specifications ..................................................................................... 3 Transformer Turns Ratio ........................................................... 15 Electrical Characteristics5 V Primary Input Supply/5 V Transformer ET Constant ......................................................... 15 Secondary Isolated Supply .......................................................... 3 Transformer Primary Inductance and Resistance ................. 15 Electrical Characteristics3.3 V Primary Input Supply/3.3 V Transformer Isolation Voltage .................................................. 16 Secondary Isolated Supply .......................................................... 3 Switching Frequency .................................................................. 16 Electrical Characteristics5 V Primary Input Supply/3.3 V Transient Response .................................................................... 16 Secondary Isolated Supply .......................................................... 4 Component Selection ................................................................ 16 Electrical Characteristics5 V Primary Input Supply/15 V Secondary Isolated Supply .......................................................... 4 Printed Circuit Board (PCB) Layout ....................................... 17 Package Characteristics ............................................................... 5 Thermal Analysis ....................................................................... 17 Regulatory Approvals (Pending) ................................................ 5 Power Consumption .................................................................. 17 Power Considerations ................................................................ 18 Insulation and Safety Related Specifications ............................ 5 DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Insulation Lifetime ..................................................................... 18 Characteristics .............................................................................. 6 Outline Dimensions ....................................................................... 19 Recommended Operating Conditions ...................................... 6 Ordering Guide .......................................................................... 19 Absolute Maximum Ratings ............................................................ 7 ESD Caution .................................................................................. 7 REVISION HISTORY 5/14Rev. 0 to Rev. A Change to Line Regulation Parameter, Table 4 ............................. 4 5/12Revision 0: Initial Version Rev. A Page 2 of 20