Isolated Synchronous Flyback Controller with Integrated Coupler

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 SOICW 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).

Applications

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

* Telecom, industrial

* Small cell

* PoE powered device

* Enterprise switches and routers

* Current mode controller for flyback topology

* ADP1071-1: programmable LLM or CCM for high VIN applications

* ADP1071-2: forced CCM operation

* Programmable slope compensation

* ntegrated 5kV Isolation (SOICW Package) or 3.0kV (LGA Package) Rated Dielectric Isolation Voltage with ADI’s, Patented iiCoupler technology

* Wide voltage supply range

* Primary VDD: up to 60 V (ADP1071-2 only)

* Secondary VDD2: up to 36 V

* 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