Analog Devices Inc./Maxim Integrated MAX7349ATG+TG104

Overview

MAX7349ATG+ from Maxim Integrated is a 24-pin TQFN-packaged I²C key-switch and sounder controller IC designed for low-EMI static matrix scanning of up to 64 metallic or resistive switches (≤1kΩ), with integrated 14-tone musical sounder output, FIFO-based key-event queuing (8-deep), and six configurable open-drain GPOs. It operates from 2.4V to 3.6V across –40°C to +125°C and supports automatic key-click feedback in medical instrumentation and industrial control panels.

For engineers reviewing the MAX7349ATG+ datasheet, MAX7349ATG+ pinout, MAX7349ATG+ application, or MAX7349ATG+ equivalent, this page delivers verified technical context, real-world design meaning for key specs, validated pin functions, confirmed alternative parts with documented functional differences, and supply-ready availability details - all specific to the MAX7349ATG+ variant in TQFN-EP package.

Technical Context

The MAX7349ATG+ implements static (non-scanned) key matrix monitoring using eight row inputs (ROW0–ROW7) and eight column/GPO terminals (COL0–COL7/PORT7), enabling deterministic low-EMI operation. Its dual-function architecture integrates an I²C-addressable key-scan controller (4 slave address options) and a separate sounder controller with double-buffered command queue and autoloop capability.

It features hardware-configurable interrupt behavior (per-event, FIFO-level, or time-based), user-programmable debounce (9ms–40ms), autorepeat delay/rate, and sounder duration (15.625ms–1s in binary steps). The SOUNDER output is push-pull, capable of driving piezo transducers, relays, or lamps directly.

Key Specifications

Pinout & Package

MAX7349ATG+ uses a 24-pin TQFN-EP (exposed paddle) package (pkg code T2444-4), 4mm × 4mm × 0.8mm, with thermal pad internally connected to GND. Pinout is identical to MAX7349AEG+ (24-pin QSOP) except for physical layout and thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar key-switch and sounder controller applications.

Compared with MAX7349AEG+, the MAX7349ATG+ offers superior thermal dissipation and smaller footprint; compared with MAX7348AEP+, it provides 24 more key positions, 3 extra GPOs, and the dedicated ALERT input - making it the only option for full-featured, thermally demanding 64-key designs.

Availability

MAX7349ATG+ is available at Aetrix Electronics and suitable for medical instrumentation, industrial HMI panels, and security access systems requiring stable component supply, extended temperature operation, and long-term lifecycle continuity.

Supply support for MAX7349ATG+ 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) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and automotive applications.

The MAX7349 is part of Maxim's low-EMI peripheral controller family, engineered specifically for reliable human-interface key matrix management and integrated audible feedback in noise-sensitive, high-reliability systems.

FAQ

What is the maximum number of keys supported by the MAX7349ATG+?

The MAX7349ATG+ supports up to 64 key switches in an 8×8 matrix configuration. This capacity assumes all eight column/GPO terminals (COL2/PORT2 through COL7/PORT7 and INT) are used exclusively for key scanning. Each terminal repurposed as a general-purpose output reduces the maximum key count by eight. The MAX7349ATG+ datasheet confirms this limit under "Product Features Table" and "Detailed Description" sections.

Does the MAX7349ATG+ include a built-in sound generator?

Yes, the MAX7349ATG+ integrates a dedicated sounder controller with 14 programmable musical frequencies (523.25Hz to 2637Hz), including the full 5th octave. It supports automatic key-click feedback, dual-tone alarms, and continuous tone generation. The SOUNDER pin is push-pull and can drive piezo transducers directly or be programmed high/low to control relays or lamps - all confirmed in the "Tone Generator" section and Electrical Characteristics table.

What package type is used for the MAX7349ATG+?

The MAX7349ATG+ uses a 24-pin TQFN-EP (thin quad flat no-lead with exposed paddle) package, 4mm × 4mm × 0.8mm, with pkg code T2444-4. The exposed paddle is internally connected to GND and must be soldered to a large ground plane for optimal thermal performance. This matches the ordering information table and "Pin Configurations" section of the MAX7349 datasheet.

Can the INT pin on the MAX7349ATG+ be used as a general-purpose output?

Yes, the INT pin on the MAX7349ATG+ is configurable as either an active-low interrupt output or an open-drain general-purpose output (GPO). When configured as a GPO, it can drive LEDs or other logic-level loads. This dual functionality is explicitly documented in the "Pin Description" table and "Detailed Description" section, where it states "If the INT pin is not required, it can be configured as an open-drain general-purpose output."

What is the operating temperature range for the MAX7349ATG+?

The MAX7349ATG+ is rated for operation from –40°C to +125°C, as specified in the "Ordering Information" table and "Absolute Maximum Ratings" section. This extended temperature range qualifies it for use in harsh environments such as industrial controls, automotive under-hood applications, and medical equipment requiring wide ambient tolerance - confirmed across all electrical characteristics tables.