Analog Devices Inc./Maxim Integrated MAXREFDES115C#

Overview

MAXREFDES115C# from Maxim Integrated is an isolated 24V-to-5V, 20W (4A) industrial reference design board implementing an active-clamp forward converter topology with the MAX17599 PWM controller, 91.5% peak efficiency at 24V input, and through-hole mounting for rapid prototyping in PLC and sensor systems.

For engineers reviewing the MAXREFDES115C# datasheet, MAXREFDES115C# pinout, MAXREFDES115C# application, or MAXREFDES115C# equivalent, key selection considerations include input UVLO/OVI thresholds (16.5V/37.0V), 250kHz switching frequency with programmable spread-spectrum dithering, hiccup-mode overcurrent protection, thermal shutdown, and compatibility with Hanrun HR051434 transformer.

Technical Context

The MAXREFDES115C# implements a wide-input (16.5V–37.0V) active-clamp forward converter using the MAX17599 controller, which integrates AUX driver for zero-voltage switching of the clamp FET and programmable dead time control to enable soft-switching operation.

It delivers regulated 5V ±0.25V output across 0–4A load range with <240mV transient spike under 2.4A↔4A load steps, employs TLV431B + optocoupler feedback for 3000V isolation, and features EN/UVLO and OVI protection with discrete resistor-divider programming.

Key Specifications

Availability

MAXREFDES115C# is available at Aetrix Electronics and suitable for programmable logic controllers (PLCs), industrial process control systems, and isolated sensor power rails requiring stable component supply, quick integration, and verified performance across line/load transients.

Supply support for MAXREFDES115C# 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management solutions for industrial, automotive, and communications markets.

The MAXREFDES reference design series targets rapid industrial power system development, delivering fully validated, Gerber-ready, and test-proven isolated DC-DC solutions based on Maxim's proprietary controllers like the MAX17599.

FAQ

What is the input voltage range supported by the MAXREFDES115C#?

The MAXREFDES115C# operates from 16.5V to 37.0V DC input, defined by its EN/UVLO turn-on threshold (16.5V) and OVI shutdown threshold (37.0V). This range accommodates industrial 24V nominal supplies with wide tolerance and brownout resilience. The MAXREFDES115C# maintains regulation and protection across this full span without external adjustment.

Does the MAXREFDES115C# include isolation, and what is its rating?

Yes, the MAXREFDES115C# provides reinforced galvanic isolation rated at 3000V_RMS, achieved through both the Hanrun HR051434 transformer and an optocoupler-based feedback path using the TLV431B shunt regulator. This meets IEC 61000-4-5 and industrial safety standards for functional isolation in PLC and sensor interfaces.

What transformer is used on the MAXREFDES115C# board?

The MAXREFDES115C# uses the Hanrun HR051434 transformer, a qualified off-the-shelf component selected for its compatibility with the active-clamp forward topology, flux handling, and thermal performance. This transformer enables compact layout and eliminates custom magnetics sourcing delays while maintaining 91.5% peak efficiency at 24V input.

How is overcurrent protection implemented on the MAXREFDES115C#?

The MAXREFDES115C# implements hiccup-mode overcurrent protection using the MAX17599's internal current-sense circuitry and negative current limit feature. During overload, the controller cycles on/off with controlled restarts, limiting average power dissipation and preventing thermal runaway. This protects both the board and downstream loads during sustained or intermittent faults.

Can the switching frequency of the MAXREFDES115C# be adjusted?

Yes, the MAXREFDES115C# operates at a nominal 250kHz switching frequency, but supports programmable frequency dithering via the MAX17599's FREQ pin to enable low-EMI spread-spectrum operation. This feature is configurable with external RC components and helps meet stringent CISPR 22/32 Class B emissions requirements without added filtering.