Analog Devices Inc./Maxim Integrated MAX7348AEP+T

Overview

MAX7348AEP+T from Maxim Integrated is a 2-wire (I²C) interfaced key-switch and sounder controller IC designed for low-EMI static matrix scanning of up to 40 metallic or resistive switches (≤1kΩ), with integrated 8-deep FIFO debouncing, user-configurable 9ms–40ms debounce time, and programmable tone generation across 14 musical frequencies (523.25Hz–2637Hz). It operates from 2.4V to 3.6V over –40°C to +125°C and targets industrial control panels requiring tactile feedback and noise-immune input management.

For engineers reviewing the MAX7348AEP+T datasheet, MAX7348AEP+T pinout, MAX7348AEP+T application, or MAX7348AEP+T equivalent, this page delivers verified functional identity, validated 20-pin QSOP package mapping, confirmed I²C slave address flexibility (4 options), real-world sounder timing accuracy (±1.2%), and precise GPO/INT dual-role configuration logic - all critical for medical instrument UI, security keypad, and industrial HMI design.

Technical Context

The MAX7348AEP+T implements static key-matrix monitoring (not dynamic scanning) to eliminate switching EMI, using dedicated row/column I/Os (ROW0–ROW7, COL0–COL4/PORT4) with configurable open-drain GPO capability on COL2–COL4. Its dual-I²C-address architecture separates key-scan control (0x71–0x77) from sounder command execution (0x79–0x7F), enabling concurrent register access without bus contention.

Internally, it integrates a 2-wire interface with selectable 20ms bus timeout, hardware interrupt generation on FIFO threshold or per-event basis, and a push-pull SOUNDER output capable of driving piezo transducers or relays. Key debounce and autorepeat parameters are fully software-configurable via dedicated registers (0x01–0x02), with power-up defaults stored in nonvolatile shadow logic.

Key Specifications

Pinout & Package

MAX7348AEP+T is housed in a 20-pin QSOP package (Pkg Code E20-1), with exposed paddle internally connected to GND for thermal performance. Pin functions are electrically validated per Maxim's official pin description table and match the MAX7348-specific 20-pin assignment (no TQFN variant for this part number).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX7349AEG+, MAX7348AEP+T offers optimized 40-key capacity in a smaller 20-pin QSOP, eliminating unused I/Os and reducing PCB area; versus TCA9554PWR, it delivers turnkey key-scan and sounder functionality with zero MCU firmware overhead for debounce, FIFO, or tone generation.

Availability

MAX7348AEP+T is available at Aetrix Electronics and suitable for medical instrument UIs, industrial control panels, and security access systems requiring stable component supply, long-term lifecycle assurance, and lead-free compliance.

Supply support for MAX7348AEP+T 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 MAX7347/MAX7348/MAX7349 product line was engineered specifically for EMI-sensitive human-interface applications requiring reliable key scanning, tactile audio feedback, and minimal MCU resource usage - targeting instrumentation, security, and medical equipment.

FAQ

What is the maximum number of key switches supported by the MAX7348AEP+T?

The MAX7348AEP+T supports up to 40 key switches, implemented via an 8-row (ROW0–ROW7) by 5-column (COL0–COL4) matrix configuration. This is explicitly defined in Maxim's datasheet Table 1 and confirmed in the General Description section. The MAX7348AEP+T does not support 64-key operation - that capability belongs exclusively to the MAX7349 family members.

Can the INT pin on the MAX7348AEP+T be used as a general-purpose output?

Yes, the INT pin on the MAX7348AEP+T can be reconfigured as an open-drain general-purpose output (GPO) by writing to the Interrupt register (address 0x03). When configured as GPO, it retains its 25mA sink capability and can drive LEDs directly. This dual-role functionality is documented in the Pin Description table and Detailed Description section of the MAX7348AEP+T datasheet.

What are the valid I²C slave addresses for the MAX7348AEP+T key-scan controller?

The MAX7348AEP+T key-scan controller supports four 7-bit slave addresses: 0x71, 0x73, 0x75, and 0x77. These are selected by connecting the AD0 pin to GND, V+, SDA, or SCL respectively, as shown in Table 3 of the datasheet. Each address has separate read/write variants (R/W bit), and the sounder controller uses corresponding addresses offset by 0x08 (e.g., 0x79, 0x7B, etc.).

Does the MAX7348AEP+T include hardware debounce logic?

Yes, the MAX7348AEP+T includes dedicated on-chip hardware debounce logic with user-configurable timing from 9ms to 40ms, controlled via the Debounce register (0x01). This eliminates the need for external RC networks or MCU-based software debounce, and is validated across the full –40°C to +125°C operating range per the Electrical Characteristics table.

What is the frequency accuracy of the tone generator in the MAX7348AEP+T?

The tone generator in the MAX7348AEP+T has a frequency accuracy of ±1.2% at +25°C, as specified in the Electrical Characteristics table under "SOUNDER Frequency Accuracy". This tolerance holds across the full 2.4V–3.6V supply range and is measured with V+ = 3.3V, ensuring consistent audio feedback pitch in real-world conditions.