Analog Devices Inc./Maxim Integrated MAX17500AEVKIT+

Overview

MAX17500AEVKIT+ from Maxim Integrated is an evaluation kit for the MAX17500A current-mode PWM controller, designed to accelerate development of universal-input isolated power supplies (rectified 85V AC to 265V AC) and telecom (-36V DC to -72V DC) applications. It supports programmable switching frequency up to 625kHz, features internal bootstrap UVLO with 21.6V startup threshold and 9.74V shutdown level, includes digital soft-start (5.6ms at 350kHz), and enables primary-side regulation via integrated error amplifier with 1.23V ±1.5% reference.

For engineers reviewing the MAX17500AEVKIT+ datasheet, MAX17500AEVKIT+ pinout, MAX17500AEVKIT+ application, or MAX17500AEVKIT+ equivalent, this kit provides validated hardware for evaluating MAX17500A-based flyback, forward, and SEPIC topologies - particularly where high-voltage startup sequencing, cycle-by-cycle current limiting (1V CS threshold), and UVLO flag timing (210μs NDRV disable delay) are critical design requirements.

Technical Context

The MAX17500AEVKIT+ implements a nonisolated flyback reference design using the MAX17500AAUB+ controller in 10-pin µMAX package. It demonstrates bootstrapped startup via tertiary-winding bias, with IN supply derived from transformer auxiliary winding and regulated by internal VCC regulator (7.0–10.5V). The board integrates all critical support circuitry: RT resistor for 350kHz switching, R12/R15 timing network, 1kΩ CS sense resistor, and UVLO/EN divider for 22V startup.

It validates key MAX17500A functional blocks: open-drain UFLG flag with 210μs propagation delay after UVLO/EN deassertion, NDRV gate driver capable of 1A sink / 0.65A source, and primary-side regulation using COMP/FB loop with 80dB gain and 2MHz unity-gain bandwidth. The kit operates across -40°C to +125°C ambient, matching the IC's rated temperature range.

Key Specifications

Availability

MAX17500AEVKIT+ is available at Aetrix Electronics and suitable for telecom power module development, universal offline AC-DC adapter qualification, and industrial isolated DC-DC converter prototyping requiring stable component supply and validated reference designs.

Supply support for MAX17500AEVKIT+ 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 ICs for industrial, communications, and computing applications.

The MAX17500 product line delivers current-mode PWM controllers optimized for universal-input and telecom power supplies, emphasizing robust high-voltage startup, primary-side regulation, and precise cycle-by-cycle current limiting without optocouplers.

FAQ

What is the primary function of the MAX17500AEVKIT+?

The MAX17500AEVKIT+ is an evaluation kit for the MAX17500A PWM controller, providing a fully assembled and tested hardware platform to validate performance in universal-input (85–265V AC) and telecom (-36V to -72V DC) isolated power supplies. It demonstrates bootstrapped startup, primary-side regulation, and UVLO sequencing - enabling rapid prototyping of flyback and forward converters before custom PCB design. The kit directly implements the MAX17500AAUB+ IC with all supporting components.

Does the MAX17500AEVKIT+ support both MAX17500A and MAX17500B variants?

No - the MAX17500AEVKIT+ is specifically configured for the MAX17500AAUB+ variant, which has a 50% maximum duty cycle and is optimized for lower-frequency, higher-voltage operation. It does not support the 75% duty-cycle MAX17500BAUB+. The board's timing resistors (R12 = 15kΩ), soft-start configuration, and feedback network are calibrated for the A-version's electrical characteristics and startup behavior.

How does the MAX17500AEVKIT+ implement primary-side regulation?

The MAX17500AEVKIT+ uses the MAX17500A's internal error amplifier to regulate output voltage without an optocoupler: the FB pin connects to a resistive divider from the tertiary winding, while COMP drives the current-sense comparator. This enables accurate primary-side regulation by monitoring reflected tertiary voltage - eliminating secondary-side feedback components and reducing bill-of-materials. The kit's schematic matches Figure 6 in the MAX17500 datasheet for this topology.

What is the role of the UFLG pin on the MAX17500AEVKIT+?

On the MAX17500AEVKIT+, the UFLG pin provides an open-drain undervoltage flag signal that asserts low when the UVLO/EN input falls below its 1.17V shutdown threshold. With a guaranteed 210μs delay between UFLG assertion and NDRV shutdown, it enables precise sequencing of secondary-side controllers or system-level power management. The kit routes UFLG to a test point and includes pull-up options for direct connection to external logic.

Can the MAX17500AEVKIT+ be used for 12V boost or SEPIC regulator evaluation?

Yes - although optimized for isolated flyback, the MAX17500AEVKIT+'s underlying MAX17500AAUB+ controller supports nonisolated topologies including boost and SEPIC. Its programmable switching frequency (25–625kHz), 1V current-limit threshold, and NDRV gate driver (1A sink / 0.65A source) are directly applicable. Users can reconfigure the board's transformerless power stage per Application Note 5485 to evaluate these configurations, leveraging the same UVLO, soft-start, and error amplifier functions validated on the kit.