Isolated Switching Regulator
With Integrated Feedback
Data Sheet
ADuM3070
FEATURES
FUNCTIONAL BLOCK DIAGRAM
V
V
ISO
DD1
Isolated PWM feedback with built in compensation
Primary side transformer driver for up to 2.5 W output power
with 5 V input voltage
RECT
X1
X2
V
REG
ADuM3070
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
V
DD2
REG
5V
PRIMARY
CONVERTER/
DRIVER
V
DDA
SECONDARY
CONTROLLER
FB
INTERNAL
FEEDBACK
OC
GND
GND
2
1
2500 V rms isolation
High common-mode transient immunity: >25 kV/µs
16-lead QSOP package
NOTES
1. V
2. V
IS THE POWER SUPPLY FOR THE PUSH-PULL TRANSFORMER.
IS THE POWER SUPPLY OF SIDE 1 OF THE ADuM3070.
DD1
DDA
Figure 1.
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.
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
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