Analog Devices Inc./Maxim Integrated MAXREFDES108#

Overview

MAXREFDES108# from Maxim Integrated is a non-isolated Power over Ethernet (PoE) powered device (PD) reference design module integrating the MAX5969A PD controller and MAX17505 synchronous step-down DC-DC converter. It accepts 36V–57V PoE input, delivers regulated 12V/1A (12W) output with ±3% accuracy and 90% peak efficiency at 48V input, and targets lighting, IP cameras, and sensors where isolation is unnecessary.

For engineers reviewing the MAXREFDES108# datasheet, MAXREFDES108# pinout, MAXREFDES108# application, or MAXREFDES108# equivalent, this module provides verified PoE PD interface compliance (IEEE 802.3af Class 3), through-hole modular placement, soft-start timing (3.2ms), RESET signal timing (2.4ms after VOUT > 11.4V), and full design files including schematics, BOM, and Gerber data.

Technical Context

The MAXREFDES108# implements a two-stage architecture: first, the MAX5969A performs IEEE 802.3af-compliant detection, classification (via 619Ω resistor for Class 3), and inrush-limited hot-swap switching; second, the MAX17505 converts the rectified PoE voltage to 12V using internal compensation, 500kHz switching, and synchronous rectification.

Input compatibility is ensured by dual bridge rectifiers (KMB110F Schottky diodes) enabling polarity-agnostic connection to PSEs; output stability is maintained via load regulation <0.2%, line regulation across 36–57V, and output ripple <100mV at both 5mA and 1A loads.

Key Specifications

Availability

MAXREFDES108# is available at Aetrix Electronics and suitable for lighting systems, IP camera power supplies, industrial sensor nodes, and non-isolated Ethernet edge devices requiring stable component supply, rapid prototyping, and production-ready reference design validation.

Supply support for MAXREFDES108# includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for industrial, communications, and computing applications.

The MAXREFDES series delivers fully validated, production-ready reference designs - MAXREFDES108# specifically targets cost-sensitive, non-isolated PoE PD implementations where safety isolation is not mandated.

FAQ

What is the primary function of MAXREFDES108#?

MAXREFDES108# is a complete non-isolated PoE powered device reference design that integrates PD interface control and DC-DC conversion. It enables rapid development of 12V/1A PoE-powered equipment such as LED lighting and IP cameras. The MAXREFDES108# board implements IEEE 802.3af Class 3 compliance and delivers verified performance metrics including 90% peak efficiency and ±3% output regulation.

Does MAXREFDES108# require external isolation components?

No, MAXREFDES108# is explicitly designed as a non-isolated PoE PD solution. It omits transformers and optocouplers to reduce cost, size, and power loss - making it appropriate for applications like ceiling-mounted LED fixtures or outdoor sensors where human contact is unlikely. The MAXREFDES108# achieves safety compliance through system-level implementation rather than on-board galvanic isolation.

How is the PD classification configured on MAXREFDES108#?

MAXREFDES108# uses a fixed 619Ω classification resistor (R1) to implement IEEE 802.3af Class 3, supporting up to 12.95W. This configuration is hardwired on the board and does not require user adjustment. The MAXREFDES108# classification signature has been validated against PSE equipment, and the MAXREFDES108# design documentation confirms full interoperability with standard 802.3af power sourcing equipment.

What are the mechanical mounting options for MAXREFDES108#?

MAXREFDES108# features 12 through-hole pins spaced at 2.54mm pitch, enabling direct soldering onto host PCBs or plug-in evaluation on the MAXREFDES98EV# carrier board. Its compact 14.0mm × 55.9mm footprint and standardized pin layout support accelerated prototyping without custom adapters. The MAXREFDES108# mechanical interface is documented in its Gerber and layout files, which are publicly available from Maxim's reference design portal.

Can MAXREFDES108# operate with non-PoE DC sources?

Yes, MAXREFDES108# accepts any 36V–57V DC source applied across its J1 input terminals (VA1/VA2 or VB1/VB2), thanks to integrated bridge rectifiers that eliminate polarity sensitivity. This allows bench testing with lab power supplies when PoE infrastructure is unavailable. The MAXREFDES108# maintains identical regulation, efficiency, and protection behavior under DC input as under PoE, per its published lab measurement data.