Analog Devices Inc./Maxim Integrated MAX17681AEVKITE#

Overview

MAX17681AEVKITE# from Maxim Integrated is an evaluation kit for the MAX17681A high-voltage iso-buck DC-DC converter IC, enabling rapid prototyping of isolated 5W power supplies with primary-side regulation, 4.5V–42V input range, and robust secondary-side overcurrent protection. It supports transformer-based isolated outputs without optocouplers and targets industrial fieldbus and PLC I/O applications.

For engineers reviewing the MAX17681AEVKITE# datasheet, MAX17681AEVKITE# pinout, MAX17681AEVKITE# application, or MAX17681AEVKITE# equivalent, this kit provides validated reference design, test points for VPRI/VOUT/SS/COMP/RESET monitoring, full thermal and hiccup-mode characterization, and direct compatibility with the MAX17681A's 10-pin TDFN package layout and control interface.

Technical Context

The MAX17681AEVKITE# implements the MAX17681A's peak-current-mode iso-buck topology using a 1:2.4 turns-ratio transformer, synchronous internal MOSFETs (R_DS(on)H = 0.85Ω typ, R_DS(on)L = 0.35Ω typ), and primary-side feedback via FB pin. It demonstrates the device's programmable EN/UVLO threshold (1.218V typ), adjustable soft-start (via SS capacitor), and open-drain RESET with 92.5%–95.5% FB window.

This kit validates the MAX17681A's dual overcurrent protection: cycle-by-cycle peak limit (1.65A typ), runaway limit (1.7A typ), and-critically-the MAX17681A-exclusive 16-consecutive-negative-current-limit hiccup trigger for reliable secondary short-circuit recovery, including active primary capacitor discharge during timeout.

Key Specifications

Availability

MAX17681AEVKITE# is available at Aetrix Electronics and suitable for industrial PLC I/O modules, isolated fieldbus interfaces, smart meter auxiliary supplies, and medical floating power supply development requiring stable component supply, fast design-in support, and production-ready reference validation.

Supply support for MAX17681AEVKITE# 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 MAX17681A product line delivers isolated DC-DC conversion without optocouplers, targeting space-constrained, high-reliability industrial systems where primary-side regulation, wide input range, and secondary fault resilience are mandatory.

FAQ

What is the primary purpose of the MAX17681AEVKITE# evaluation kit?

The MAX17681AEVKITE# is a fully assembled and tested evaluation platform for the MAX17681A iso-buck controller IC. It enables engineers to validate isolated power supply designs up to 5W, verify secondary-side overcurrent protection behavior, measure loop stability with COMP network tuning, and confirm thermal performance across –40°C to +125°C. The MAX17681AEVKITE# includes all critical passive components, transformer, and test points aligned to the MAX17681A's 10-pin TDFN footprint.

Can the MAX17681AEVKITE# be used with the MAX17681 (non-A) IC?

No - the MAX17681AEVKITE# is specifically designed and validated for the MAX17681A IC. While pin-compatible, the MAX17681 lacks the secondary-side overcurrent protection logic implemented in the MAX17681A, including the 16-consecutive-negative-current-limit hiccup trigger and active primary capacitor discharge during timeout. Using MAX17681 on this board will not demonstrate robust secondary short-circuit recovery and may exhibit unstable recovery behavior.

Does the MAX17681AEVKITE# include firmware or software tools?

No - the MAX17681AEVKITE# is a hardware-only evaluation platform. It contains no microcontroller, firmware, or USB interface. Configuration is entirely analog: EN/UVLO threshold set by external resistor divider, soft-start time set by SS capacitor value, output voltage set by FB resistor divider, and loop compensation tuned via COMP RC network. All functionality is defined by the MAX17681A's internal analog control architecture.

What transformer is used on the MAX17681AEVKITE# board?

The MAX17681AEVKITE# uses a custom-wound transformer with a 1:2.4 turns ratio (NPRI:NSEC), optimized for the iso-buck topology and validated for 24V_OUT/100mA operation at 24V_IN. Its parameters include ≤1% leakage inductance relative to magnetizing inductance, 165°C insulation rating, and RMS current ratings matching MAX17681A's peak/average switching profiles. Full specs are documented in the MAX17681A EV kit user guide.

How does the MAX17681AEVKITE# demonstrate hiccup-mode behavior during secondary short-circuit events?

The MAX17681AEVKITE# directly demonstrates the MAX17681A's unique hiccup response: upon detecting 16 consecutive negative current limit events (indicating secondary overload), it enters a 32,768-cycle timeout during which the low-side switch actively discharges the primary capacitor toward zero. After timeout, both primary and secondary outputs undergo synchronized soft-start. This behavior - confirmed via oscilloscope capture of VPRI, VOUT, and RESET - ensures reliable recovery after secondary faults, a capability absent in the MAX17681.