Analog Devices Inc./Maxim Integrated MAX1806EUA15+

Overview

MAX1806EUA15+ from Maxim Integrated is a 1.5V fixed-output, 500mA low-dropout linear regulator with ±1% output voltage accuracy, 175mV dropout at full load, and 210μA ground current. It features an active-low power-OK (POK) output, 0.02μA shutdown current, and thermal/short-circuit protection. Designed for space-constrained portable systems, it powers core logic rails in cellular phones and USB hubs.

For engineers reviewing the MAX1806EUA15+ datasheet, MAX1806EUA15+ pinout, MAX1806EUA15+ application, or MAX1806EUA15+ equivalent, key selection criteria include guaranteed 500mA output under 175mV dropout, preset 1.5V output with no external feedback, POK monitoring capability, and compatibility with 1μF input / 10μF low-ESR output capacitors in the 8-pin power-μMAX package.

Technical Context

The MAX1806EUA15+ implements a P-channel MOSFET pass transistor architecture enabling ultra-low quiescent current (210μA typical) and minimal dropout voltage without base-drive losses. Its dual-mode SET pin accepts either GND (for factory-trimmed 1.5V output) or an external resistor divider (for adjustable operation), with internal 800mV reference and 35–125mV threshold detection.

Power-OK functionality uses an open-drain N-channel output referenced to 93% of nominal VOUT, requiring only a 100kΩ pullup to OUT. Thermal protection activates at +170°C with 20°C hysteresis, and short-circuit current limiting holds output at ~1.4A typical during fault conditions.

Key Specifications

Pinout & Package

The MAX1806EUA15+ is housed in an 8-pin power-μMAX package (1.3W rating) with an exposed metal thermal pad on the underside for PCB heat sinking. Both IN and OUT pins are duplicated (pins 1&2, 7&8) to reduce trace resistance and improve current handling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A2015PDQNR and MCP1826T-1502E/DB, the MAX1806EUA15+ uniquely combines 175mV dropout, integrated POK, and thermal hysteresis in a thermally enhanced μMAX package - making it optimal for portable systems demanding both efficiency and robust fault management.

Availability

MAX1806EUA15+ is available at Aetrix Electronics and suitable for cellular telephones, USB hubs, and notebook computers requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MAX1806EUA15+ 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, communications, and consumer applications.

The MAX1806 product line delivers low-noise, low-quiescent-current LDOs optimized for battery-powered portable electronics where small size, high accuracy, and intelligent protection features are essential.

FAQ

What is the output voltage tolerance of the MAX1806EUA15+ over temperature and load?

The MAX1806EUA15+ guarantees ±1% output voltage accuracy at +85°C and 100mA load. Over the full operating range (-40°C to +85°C, 1mA to 500mA load, VIN > VOUT + 0.5V), output voltage remains within ±3% of 1.5V. This tight tolerance ensures reliable operation of 1.5V I/O standards without external calibration. The MAX1806EUA15+ achieves this via laser-trimmed internal feedback, eliminating drift-related errors common in resistor-based solutions.

Does the MAX1806EUA15+ require external components to operate in fixed 1.5V mode?

No, the MAX1806EUA15+ operates in fixed 1.5V mode with only two mandatory external components: a 1μF ceramic capacitor on IN and a 10μF low-ESR capacitor on OUT. The SET pin must be connected to GND to select preset mode - no resistors or additional circuitry are needed. This simplifies design and improves reliability compared to adjustable LDOs. The MAX1806EUA15+ integrates all regulation references and error amplification internally.

How does the POK output function on the MAX1806EUA15+?

The POK output on the MAX1806EUA15+ is an open-drain N-channel driver that pulls low when VOUT falls below 93% of 1.5V (i.e., 1.395V). It goes high-impedance once VOUT exceeds this threshold. A 100kΩ pullup resistor to OUT is required for proper logic-level signaling. During shutdown, POK is forced low regardless of output voltage. This behavior allows the MAX1806EUA15+ to provide deterministic power-good status to microcontrollers without external comparators.

What thermal management considerations apply to the MAX1806EUA15+ package?

The MAX1806EUA15+ uses an 8-pin power-μMAX package with an exposed metal thermal pad on the underside. For effective heat dissipation, this pad must be soldered to a large PCB copper area or internal ground plane using multiple thermal vias. Failure to do so limits continuous power dissipation to 1.3W at +70°C ambient, with 17mW/°C derating above that. Proper thermal design enables the MAX1806EUA15+ to sustain 500mA output even in compact enclosures.

Can the MAX1806EUA15+ be used with input voltages below 2.25V?

No, the MAX1806EUA15+ has a minimum specified input voltage of +2.25V per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below this violates the device's UVLO threshold (1.85V–2.15V rising) and risks unstable regulation or failure to start. Even though dropout is only 175mV, the internal circuitry requires ≥2.25V to bias control blocks reliably. For sub-2.25V inputs, consider alternative regulators such as the MAX1725 or TPS7A05 series. The MAX1806EUA15+ is not rated for operation below its specified VIN min.