Analog Devices Inc./Maxim Integrated MAX9724AEVKIT+

Overview

MAX9724AEVKIT+ from Maxim Integrated is an evaluation kit for the MAX9724A stereo headphone amplifier IC, designed to validate DirectDrive® architecture performance in portable audio systems. It supports rapid prototyping of 60mW/channel, ground-referenced output amplification into 32Ω loads with 0.02% THD+N, 80dB PSRR at 1kHz, and RF noise rejection up to 67dB - enabling capacitor-free headphone output staging in space-constrained MP3 players and smartphones.

For engineers reviewing the MAX9724AEVKIT+ datasheet, MAX9724AEVKIT+ pinout, MAX9724AEVKIT+ application, or MAX9724AEVKIT+ equivalent, this kit provides verified reference circuitry, test points for SHDN control, left/right input/output monitoring, and charge-pump capacitor validation - critical for low-THD, low-power, single-supply audio subsystem design with no DC-blocking capacitors.

Technical Context

The MAX9724AEVKIT+ implements the full functional schematic of the MAX9724A IC, including its integrated charge pump (270kHz oscillator), dual Class AB output stages, and click-and-pop suppression circuitry. It validates the DirectDrive® architecture's ability to generate bipolar supply rails (VDD and PVSS) from a single 2.7V–5.5V input, enabling true ground-referenced AC-coupled outputs without external DC-blocking capacitors.

Board-level features include configurable gain via external R_IN/R_F resistors (supporting adjustable -1.5V/V nominal), test points for measuring shutdown current (<0.1μA), PSRR response, and RF susceptibility mitigation - all aligned with the IC's specified -40°C to +85°C operating range and UCSP/TQFN package thermal profiles.

Key Specifications

Availability

MAX9724AEVKIT+ is available at Aetrix Electronics and suitable for MP3 player development, smartphone audio subsystem validation, and notebook PC headphone driver qualification requiring stable component supply and pre-verified reference designs.

Supply support for MAX9724AEVKIT+ 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 portable, industrial, and communications applications.

The MAX9724A product line delivers ultra-low-power, capacitorless stereo headphone amplification targeting battery-operated consumer audio devices where board area, height, and EMI robustness are critical constraints.

FAQ

What is the primary purpose of the MAX9724AEVKIT+?

The MAX9724AEVKIT+ is an evaluation kit designed exclusively to demonstrate and validate the performance of the MAX9724A stereo headphone amplifier IC. It provides a fully assembled, tested PCB with all necessary support components - including flying capacitors, input coupling networks, and test points - to verify DirectDrive® functionality, THD+N, PSRR, RF rejection, and shutdown behavior under real operating conditions.

Does the MAX9724AEVKIT+ include the MAX9724A IC pre-mounted?

Yes, the MAX9724AEVKIT+ ships with a factory-installed MAX9724AETC+ (12-pin TQFN-EP) IC mounted on the evaluation board. This ensures immediate out-of-box testing of the complete signal chain - from left/right analog inputs through the charge pump and dual output stages to headphone-load outputs - without requiring soldering or component selection.

Can the MAX9724AEVKIT+ be used to evaluate both MAX9724A and MAX9724B variants?

No - the MAX9724AEVKIT+ is specifically configured for the MAX9724A variant, which features externally adjustable gain via R_IN/R_F resistors. The MAX9724B has fixed -1.5V/V gain and different internal biasing; its evaluation requires the separate MAX9724BEVKIT+. Using the MAX9724AEVKIT+ for MAX9724B characterization would yield invalid gain and THD+N results.

What power supply requirements does the MAX9724AEVKIT+ support?

The MAX9724AEVKIT+ operates from a single 2.7V to 5.5V DC supply, matching the MAX9724A IC's specification. It includes onboard bypass capacitors and accepts input via a standard 2.1mm barrel jack or screw-terminal block. The board draws 3.5mA quiescent current and less than 0.1μA in shutdown - enabling direct integration into battery-powered prototype systems.

How does the MAX9724AEVKIT+ validate RF noise rejection claims?

The MAX9724AEVKIT+ implements the exact layout and decoupling recommended in the MAX9724A datasheet to suppress RF coupling paths. Its validated 67dB RF rejection improvement (vs. typical amplifiers at 1800MHz) was confirmed using standardized 50V/m RF field exposure per Table 1 in the datasheet - with measurement points accessible via dedicated SMA connectors and oscilloscope test points on the board.