ADUM3070 Datasheet, PDF (1/20 Pages) Analog Devices – Isolated Switching Regulator

Data Sheet
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
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.
Isolated Switching Regulator
With Integrated Feedback
ADuM3070
FUNCTIONAL BLOCK DIAGRAM
V_DD1
RECT
V_ISO
V_DDA
X1 X2
V_REG
ADuM3070
PRIMARY
CONVERTER/
DRIVER
GND₁
REG
INTERNA L
FEEDBACK
SECONDA RY
CONTROLLER
GND₂
V_DD2
5V
FB
OC
NOTES
1. V_DD1 IS THE POWER SUPPLY FOR THE PUSH-PULL TRANSFORMER.
2. V_DDA IS THE POWER SUPPLY OF SIDE 1 OF THE ADuM3070.
Figure 1.
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.}
Rev. 0
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
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registered trademarks are the property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone]
www.analog.com
Fax: [phone]
©2012 Analog Devices, Inc. All rights reserved.