Analog Devices Inc./Maxim Integrated MAX3391EEUD+

Overview

MAX3391EEUD+ from Maxim Integrated is a quad unidirectional ±15kV ESD-protected logic-level translator enabling bidirectional voltage translation between VL (1.2V–5.5V) and VCC (1.65V–5.5V) domains, supporting up to 8Mbps data rate with 1μA three-state supply current and slew-rate limiting for EMI reduction - used in SPI/I²C interfaces between low-voltage ASICs and 3.3V/5V systems.

For engineers reviewing the MAX3391EEUD+ datasheet, MAX3391EEUD+ pinout, MAX3391EEUD+ application, or MAX3391EEUD+ equivalent, key selection criteria include guaranteed 8Mbps operation across full voltage range, ±15kV HBM ESD protection on VCC-side I/Os, thermal short-circuit protection, three-state enable control referenced to VL, and compatibility with 1.2V logic inputs.

Technical Context

The MAX3391EEUD+ implements unidirectional level translation (VL → VCC only) using MOSFET-based pass-gate architecture with integrated speed-up circuitry. It features independent input thresholds (VIHL = VL − 0.2V, VIHC = VCC − 0.4V) and output drive capability (VOHL = 0.67×VL, VOHC = 0.67×VCC at 20µA), ensuring rail-to-rail signal integrity across mixed-voltage domains.

Its three-state mode is activated by pulling the THREE-STATE pin low (logic-referenced to VL), disabling internal 10kΩ pullups and placing all I/O lines in high-impedance state. Thermal protection triggers automatic entry into three-state mode at TJ = +152°C and recovers at +142°C, preventing latch-up under sustained overload.

Key Specifications

Pinout & Package

MAX3391EEUD+ is packaged in a 14-pin TDFN (3mm × 3mm, EP) with wettable flanks, optimized for automated optical inspection and high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar unidirectional level translation applications.

Compared with TXB0104RUTR and SN74AVC4T245PWR, the MAX3391EEUD+ delivers superior system-level reliability via ±15kV HBM ESD hardening and autonomous thermal fault response - critical for consumer-facing ports and unattended embedded deployments.

Availability

MAX3391EEUD+ is available at Aetrix Electronics and suitable for smart card readers, portable POS systems, cell-phone cradles, and SPI/I²C interface designs requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for MAX3391EEUD+ 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 industrial, medical, communications, and consumer applications.

The MAX3372E–MAX3379E/MAX3390E–MAX3393E family was engineered specifically for robust, low-power voltage translation in portable and multivoltage embedded systems - emphasizing ESD resilience, wide supply flexibility, and seamless integration with sub-1.8V logic cores.

FAQ

What is the maximum data rate supported by the MAX3391EEUD+ under standard operating conditions?

The MAX3391EEUD+ guarantees 8Mbps operation across its full specified voltage range (VL = +1.2V to +5.5V, VCC = +1.65V to +5.5V). At narrower voltage combinations - such as +1.8V ≤ VL ≤ VCC ≤ +2.5V or +2.5V ≤ VL ≤ VCC ≤ +3.3V - it achieves up to 16Mbps. These higher rates depend on load capacitance (<15pF), driver impedance (≤50Ω), and ambient temperature, and are documented in the Timing Characteristics table of the MAX3391EEUD+ datasheet.

Does the MAX3391EEUD+ support bidirectional level translation?

No, the MAX3391EEUD+ is a unidirectional level translator configured exclusively for VL → VCC signal flow. It does not support reverse translation (VCC → VL). For bidirectional applications, designers must select alternate parts from the same family - such as the MAX3377E or MAX3378E - or implement dual unidirectional devices with direction control logic. The MAX3391EEUD+ pinout and internal architecture lack the transmission-gate structure required for automatic bidirectional operation.

How does the three-state mode function on the MAX3391EEUD+?

The MAX3391EEUD+ enters three-state mode when the THREE-STATE pin is pulled low (logic-low referenced to VL). This action disables internal 10kΩ pullup resistors on all I/O lines, placing I/O VL1–VL4 and I/O VCC1–VCC4 in high-impedance state and reducing total supply current to <1µA. During this mode, I/O voltages must remain within −0.3V to (VL + 0.3V) and −0.3V to (VCC + 0.3V), respectively. The feature enables multidrop bus sharing and low-power system suspend states.

What ESD protection levels does the MAX3391EEUD+ provide, and on which pins?

The MAX3391EEUD+ provides ±15kV ESD protection per Human Body Model (HBM) on all I/O VCC pins (I/O VCC1–VCC4). It also meets ±8kV contact discharge and ±10kV air-gap discharge per IEC 1000-4-2. Protection is active in normal operation, three-state mode, and powered-down states. No external ESD components are needed for I/O VCC lines in most end-equipment designs complying with IEC 61000-4-2 Level 3 requirements.

Can the MAX3391EEUD+ operate with VL higher than VCC?

During power-up sequencing, the MAX3391EEUD+ tolerates VL exceeding VCC by up to 0.3V (i.e., VL ≤ VCC + 0.3V) without damage. However, for reliable logic-level translation and output drive, VL must remain ≤ VCC + 0.3V during steady-state operation. Exceeding this limit risks incorrect threshold behavior, degraded noise margins, and potential overstress on internal protection structures - violating Absolute Maximum Ratings and voiding guaranteed performance.