Isolated Synchronous Flyback Controller

with Integrated iCoupler

Data Sheet

ADP1071-1/ADP1071-2

Rev. B

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FEATURES

Current mode controller for flyback topology

applications

ADP1071-2: forced CCM operation

Programmable slope compensation

Integrated 5 kV isolation (wide body SOIC package) or 3.0 kV

(LGA package) rated dielectric isolation voltage with

Wide voltage supply range

Integrated 1 A primary side MOSFET driver

Integrated 1 A secondary side MOSFET drivers for

synchronous rectification

Integrated error amplifier and <1% accurate reference voltage

Programmable frequency range: 50 kHz to 600 kHz

Duty cycle clamp limit 85%

Programmable soft start and soft start from precharged load

Protection features such as short circuit, output overvoltage,

and overtemperature protection

Power saving LLM using MODE pin (ADP1071-1only)

Cycle by cycle input overcurrent protection

Precision enable UVLO with hysteresis

Frequency synchronization

Safety and regulatory approvals (pending)

UL recognition

5000 V rms for 1 minute per UL 1577 (for wide body

SOIC package)

3000 V rms for 1 minute per UL 1577 (for LGA package)

CSA Component Acceptance Notice 5A

VDE certificate of conformity

DIN V VDE V 0884-10 (VDE V 0884-10):2006-12

CQC certification per GB4943.1-2011

Available in 16-lead SOIC_W package and 24 terminal LGA

package

APPLICATIONS

Isolated dc-to-dc or ac-to-dc power conversion

Telecom, industrial

Small cell

PoE powered device

Enterprise switches and routers

FUNCTIONAL BLOCK DIAGRAM

FLYBACK

TOPOLOGY

BIAS

WINDING

OUTPUT

INPUT

SYNCHRONOUS

RECTIFIER

OPTIONAL

START-UP

CIRCUITRY

ADP1071-1/

ADP1071-2

Figure 1.

GENERAL DESCRIPTION

The ADP1071-1/ADP1071-2 are pulse-width modulation

(PWM) current mode fixed frequency synchronous flyback

controllers designed for isolated dc-to-dc power supplies.

Analog Devices proprietary iCouplers® are integrated in the

ADP1071-1/ADP1071-2 to eliminate the bulky signal trans-

formers and optocouplers that transmit signals over the isolation

boundary. Integrating the iCouplers reduces system design

complexity, cost, and component count and improves overall

system reliability. With the integrated isolators and metal-oxide

semiconductor field effect transistor (MOSFET) drivers on both

the primary and the secondary side, the ADP1071-1/ADP1071-2

offer a compact system level design and yield a higher efficiency

than a diode rectified flyback converter at heavy loads.

Output regulation is achieved by sensing the output voltage on

the secondary side, where the feedback and the PWM signals

are transmitted between the primary and secondary sides

through the iCouplers.

The ADP1071-1/ADP1071-2 are offered in a 16-lead SOIC_W

package with an isolation voltage rating of 5 kV rms. The

ADP1071-2 is designed for isolated dc-to-dc applications

typically with an input voltage less than 36 V, and the

ADP1071-1 targets high input voltage applications, in which the

dc input voltage can exceed 60 V.

The ADP1071-1/ADP1071-2 offer features such as input

current protection, output overvoltage protection (OVP),

undervoltage lockout (UVLO), precision enable with adjustable

hysteresis, overtemperature protection (OTP), and power

saving light load mode (LLM).