Analog Devices Inc./Maxim Integrated MAX1806EUA15+T

Overview

MAX1806EUA15+T 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, PDAs, and USB hubs.

For engineers reviewing the MAX1806EUA15+T datasheet, MAX1806EUA15+T pinout, MAX1806EUA15+T application, or MAX1806EUA15+T equivalent, key selection criteria include guaranteed 500mA output under 175mV dropout, preset 1.5V output with no external feedback, POK monitoring capability, and operation across –40°C to +85°C in the 8-pin power-μMAX package.

Technical Context

The MAX1806EUA15+T uses an internal PMOS pass transistor with ~0.4Ω R_DS(ON), enabling low dropout and eliminating base-drive current loss typical of PNP-based regulators. Its dual-mode SET input automatically selects between factory-trimmed 1.5V output (when SET = GND) and adjustable mode (when external resistor divider is connected).

Regulation relies on a precision 0.8V internal reference and error amplifier comparing feedback against V_SET. The POK output asserts low when V_OUT falls below 93% of nominal (1.395V), using an open-drain N-channel structure requiring external pull-up. Thermal shutdown activates at +170°C with 20°C hysteresis.

Key Specifications

Pinout & Package

The MAX1806EUA15+T is housed in an 8-pin power-μMAX package (1.3W thermal rating) with an exposed metal thermal pad on the underside for PCB heat sinking. Both IN and OUT pins are dual-bonded to reduce parasitic 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 MCP1826-1502E/DB, the MAX1806EUA15+T uniquely combines 500mA capability, 175mV dropout, integrated POK, and 0.02μA shutdown in a thermally enhanced μMAX package - making it optimal for portable systems requiring robust power supervision and extended battery life.

Availability

MAX1806EUA15+T is available at Aetrix Electronics and suitable for cellular phone baseband power, USB hub controller rails, and industrial PDA logic supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

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

The MAX1806 series targets ultra-low-power, high-accuracy LDO regulation in space-constrained portable electronics - emphasizing minimal dropout, sub-μA shutdown, and integrated power supervision for battery-operated systems.

FAQ

What is the guaranteed output voltage tolerance for MAX1806EUA15+T over temperature and load?

The MAX1806EUA15+T guarantees ±1% output voltage accuracy over –40°C to +85°C and for output currents from 1mA to 500mA, provided input voltage exceeds V_OUT + 0.5V. At +85°C and 100mA load, the tolerance tightens to ±1%, and across full temperature/load range with proper input margin, it remains within ±1.5%.

Can MAX1806EUA15+T be used in adjustable-output configurations?

No - the MAX1806EUA15+T is factory-trimmed for fixed 1.5V output and internally connects the SET pin to GND. While the MAX1806 family supports adjustable mode via external resistors on the SET pin, this functionality is disabled in the MAX1806EUA15+T variant per its ordering code and internal configuration.

What is the minimum input voltage required for MAX1806EUA15+T to maintain regulation at 500mA load?

The MAX1806EUA15+T requires a minimum input voltage of 1.675V to maintain regulation at 500mA load, calculated as V_OUT + V_DROPOUT = 1.5V + 0.175V. Below this, the device enters dropout and output voltage drops linearly with input; the absolute minimum input rating is 2.25V for guaranteed specification compliance.

How does the POK output function on MAX1806EUA15+T, and what external components are needed?

The POK output on MAX1806EUA15+T is an open-drain N-channel driver that pulls low when V_OUT falls below 93% of 1.5V (1.395V). To generate a logic-high signal when regulation is valid, a 100kΩ pull-up resistor from POK to OUT is required. During shutdown, POK is forced low regardless of output voltage.

Is the exposed thermal pad on the MAX1806EUA15+T package electrically connected, and how must it be handled on the PCB?

Yes - the exposed thermal pad on the MAX1806EUA15+T is internally connected to GND. It must be soldered to a large PCB copper area or ground plane using multiple thermal vias to ensure effective heat dissipation and meet the 1.3W power rating. Leaving it unconnected degrades thermal performance and risks junction overheating under full load.