Analog Devices Inc./Maxim Integrated MAX17681EVKITE#

Overview

MAX17681EVKITE# from Maxim Integrated is an evaluation kit for the MAX17681A high-voltage iso-buck DC-DC controller IC, enabling rapid prototyping of isolated 5W power supplies with primary-side regulation. It supports 4.5V–42V input, delivers up to 24V/100mA secondary output via a 1:2.4 transformer, and implements peak-current-mode control with programmable soft-start, hiccup-mode protection, and ±1.7% feedback accuracy.

For engineers reviewing the MAX17681EVKITE# datasheet, MAX17681EVKITE# pinout, MAX17681EVKITE# application, or MAX17681EVKITE# equivalent, this page provides verified board-level specifications, thermal performance data, supported transformer configurations, reset timing behavior, and design guidance for PLC I/O modules, smart meters, and isolated fieldbus interfaces.

Technical Context

The MAX17681EVKITE# implements the MAX17681A controller in a fully assembled, tested reference design using a 10-pin TDFN (3mm × 2mm) IC, 1:2.4 turns-ratio transformer (T1), all-ceramic passive layout (C1–C8, R1–R4, Z1), and integrated soft-start (3300pF on SS), compensation (RC network on COMP), and reset (open-drain, 1024-cycle delay) circuitry. It operates across –40°C to +125°C ambient with thermal shutdown at +165°C junction temperature.

It validates the iso-buck topology's ability to generate regulated isolated outputs without optocouplers by leveraging primary-side voltage scaling, synchronous MOSFET drive (0.55Ω high-side / 0.2Ω low-side R_DS(on)), and robust secondary-side overcurrent detection-triggering 32,768-cycle hiccup mode after 16 consecutive negative current limit events, followed by active primary capacitor discharge and dual-rail soft-start recovery.

Key Specifications

Availability

MAX17681EVKITE# is available at Aetrix Electronics and suitable for PLC I/O module development, smart meter power architecture validation, and isolated fieldbus interface design requiring stable component supply, full documentation access, and production-ready reference schematics.

Supply support for MAX17681EVKITE# 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 applications.

The MAX17681EVKITE# belongs to Maxim's iso-buck evaluation platform family, designed specifically to accelerate adoption of optocoupler-free isolated DC-DC conversion in space-constrained, high-reliability industrial power systems.

FAQ

What is the purpose of the MAX17681EVKITE# evaluation kit?

The MAX17681EVKITE# is a fully assembled evaluation board for the MAX17681A iso-buck DC-DC controller. It demonstrates a complete 5W isolated power supply design using primary-side regulation, eliminating the need for optocouplers. Engineers use the MAX17681EVKITE# to validate transformer selection, verify hiccup-mode fault recovery, measure efficiency across input voltage range (4.5V–42V), and assess thermal performance under load before committing to custom PCB layout.

Does the MAX17681EVKITE# support secondary-side overcurrent protection?

Yes - the MAX17681EVKITE# implements the MAX17681A's enhanced secondary-side overcurrent protection. When a secondary short occurs, the MAX17681EVKITE# triggers hiccup mode after detecting 16 consecutive negative current limit events, actively discharges the primary capacitor during the 32,768-cycle timeout, and performs synchronized soft-start on both primary and secondary rails for robust recovery - a capability not present in the base MAX17681.

What transformer is used on the MAX17681EVKITE# board?

The MAX17681EVKITE# uses a custom-wound transformer labeled T1 with a 1:2.4 turns ratio (NPRI:NSEC), optimized for the iso-buck topology. This ratio scales the regulated ~9.6V primary output (V_PRI) to 24V secondary output (V_OUT). The transformer meets reinforced insulation requirements and supports continuous 100mA output current with <1% leakage inductance relative to magnetizing inductance - critical for tight voltage regulation on the MAX17681EVKITE#.

How does the RESET signal behave on the MAX17681EVKITE#?

On the MAX17681EVKITE#, the open-drain RESET output asserts low when the primary feedback voltage (FB) drops below 92.5% of its nominal setpoint, and releases (goes high-impedance) 1024 switching cycles after FB rises above 95.5%. During hiccup mode triggered by secondary fault, RESET remains low due to primary voltage collapse - providing a reliable system-level fault indicator. RESET is valid only when VIN > 4.5V and EN/UVLO is asserted.

Can the MAX17681EVKITE# be used for medical equipment power supply validation?

Yes - the MAX17681EVKITE# is explicitly listed in Maxim's documentation for "Isolated Power Supplies in Medical Equipment" applications. Its reinforced isolation (achieved via transformer T1), –40°C to +125°C operation, ±1.7% regulation accuracy, and hiccup-mode fault containment meet key safety and reliability requirements for auxiliary power in Class II medical devices. However, final regulatory certification (IEC 60601-1) requires system-level testing beyond the MAX17681EVKITE# board alone.