Analog Devices Inc./Maxim Integrated MAX8864SEUK

Overview

The MAX8864SEUK from Maxim Integrated is a low-dropout linear regulator with fixed 2.84V output, delivering up to 120mA from a +2.5V to +6.5V input. It features an internal pMOSFET pass transistor, 55mV dropout at 50mA, 68μA no-load supply current, and auto-discharge functionality during shutdown-making it ideal for battery-powered cordless telephones and PCMCIA cards.

For engineers reviewing the MAX8864SEUK datasheet, MAX8864SEUK pinout, MAX8864SEUK application, or MAX8864SEUK equivalent, key selection criteria include its SOT23-5 package, Dual Mode™ operation (fixed/adjustable), reverse battery protection, thermal shutdown at 170°C, and guaranteed -40°C to +85°C operating range.

Technical Context

The MAX8864SEUK uses a 1.25V bandgap reference and error amplifier to regulate output via a p-channel MOSFET pass transistor with typical R_DS(ON) of 1.1Ω. Its Dual Mode™ comparator selects feedback path based on SET pin voltage: below 60mV enables internal fixed-voltage regulation (2.84V).

Unlike PNP-based LDOs, it maintains constant 80μA operating supply current across load conditions-including dropout-due to zero gate-drive current requirement. The MAX8864 variant adds active output discharge through a 300Ω internal switch when SHDN is asserted.

Key Specifications

Pinout & Package

Package: 5-pin SOT23 (U5+1 outline, RoHS-compliant, JEDEC MO-178AA). GND pin serves dual role as electrical ground and thermal heatsink-requires connection to large copper area for optimal thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout, fixed-output regulator applications.

Compared with MAX8863SEUK, the MAX8864SEUK adds critical auto-discharge for clean power-down sequencing; versus MCP1702T-2802E/TO, it trades lower quiescent current for integrated protections essential in portable telecom equipment.

Availability

MAX8864SEUK is available at Aetrix Electronics and suitable for cordless telephones, PCMCIA cards, and hand-held instruments requiring stable component supply with guaranteed -40°C to +85°C operation and RoHS-compliant packaging.

Supply support for MAX8864SEUK 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, automotive, and communications applications.

The MAX8863/MAX8864 product line targets battery-powered portable electronics, emphasizing ultra-low quiescent current, small footprint, and integrated protection features for reliable operation in space-constrained, safety-critical systems.

FAQ

What output voltage does the MAX8864SEUK deliver, and how is it set?

The MAX8864SEUK delivers a factory-trimmed fixed output voltage of 2.84V (±0.09V over temperature). This is achieved by connecting the SET pin directly to GND, which activates the internal feedback resistor divider. No external components are required for fixed-voltage operation-making the MAX8864SEUK a drop-in solution for 2.84V rail generation in portable systems.

Does the MAX8864SEUK support adjustable output voltage, and if so, what is the range?

Yes, the MAX8864SEUK supports adjustable output voltage from 1.25V to 6.5V when the SET pin is configured with an external resistor divider instead of being tied to GND. The output follows V_OUT = 1.25V × (1 + R₁/R₂). This flexibility allows the same MAX8864SEUK footprint to serve multiple voltage rails-though the S-version designation confirms its primary use case is fixed 2.84V regulation.

How does the auto-discharge feature of the MAX8864SEUK work, and why is it important?

The MAX8864SEUK includes an internal 300Ω discharge path from OUT to GND that activates when the SHDN pin is pulled low. This actively pulls the output voltage to ground within microseconds, preventing residual charge from backfeeding into downstream circuitry or causing undefined logic states during power-down. This feature is critical in systems with multiple power domains or strict sequencing requirements-distinguishing the MAX8864SEUK from the MAX8863SEUK.

What protection features are built into the MAX8864SEUK?

The MAX8864SEUK integrates four key protections: (1) reverse battery protection (<1mA reverse current if VIN or SHDN goes below GND), (2) thermal shutdown at 170°C with 20°C hysteresis, (3) short-circuit current limiting (~280mA), and (4) output discharge during shutdown. These features ensure robust operation in consumer handhelds where battery handling, ambient temperature swings, and fault conditions are common-making the MAX8864SEUK more resilient than basic LDOs.

Can the MAX8864SEUK operate from a single alkaline cell, and what is its minimum input voltage?

Yes-the MAX8864SEUK operates from +2.5V to +6.5V input, making it compatible with a single fresh alkaline cell (nominal 1.5V, up to 1.65V) only when boosted, but fully functional across two alkaline cells (3.0V–3.3V) or single Li-ion (3.0V–4.2V). Its 55mV dropout at 50mA means it regulates cleanly down to VIN = 2.895V for 2.84V output-supporting extended runtime as the battery discharges.