Analog Devices Inc./Maxim Integrated MAX1806EUA08+T

Overview

MAX1806EUA08+T from Maxim Integrated is a 500mA low-dropout linear regulator with fixed 0.8V output, ±1% accuracy, 175mV dropout at full load, and 210μA ground current. It features an active-low power-OK (POK) output, 0.02μA shutdown current, thermal shutdown, and short-circuit protection. Designed for space-constrained portable systems requiring precise low-voltage rail generation.

For engineers reviewing the MAX1806EUA08+T datasheet, MAX1806EUA08+T pinout, MAX1806EUA08+T application, or MAX1806EUA08+T equivalent, key selection criteria include guaranteed 500mA output at 0.8V, ultra-low quiescent current in active and shutdown modes, POK monitoring capability, thermal overload behavior, and compatibility with ceramic output capacitors down to 0.1Ω ESR.

Technical Context

The MAX1806EUA08+T uses an internal P-channel MOSFET 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 feedback architecture automatically selects preset regulation (via grounded SET pin) or adjustable mode (via external resistor divider), with a precise 800mV internal reference.

Regulation stability relies on a 10μF low-ESR ceramic capacitor at OUT and 1μF at IN; the exposed thermal pad on the underside of the 8-pin power-μMAX package must be soldered to PCB ground for effective thermal management. The POK output asserts low when V_OUT falls below 93% of nominal, using open-drain N-channel logic referenced to V_OUT.

Key Specifications

Pinout & Package

The MAX1806EUA08+T is housed in an 8-pin power-μMAX package (1.3W rating) with an exposed metal thermal pad on the underside, requiring connection to PCB ground plane for thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-voltage LDO regulator applications.

Compared with TPS7A0508PDBVR and MCP1804T-0802I/OT, the MAX1806EUA08+T uniquely delivers 500mA at 0.8V with integrated POK, thermal protection, and a thermally enhanced power-μMAX package - making it the sole option among the three for high-current, safety-critical, or thermally constrained 0.8V applications.

Availability

MAX1806EUA08+T is available at Aetrix Electronics and suitable for notebook computers, cellular telephony subsystems, USB hub designs, and industrial sensor nodes requiring stable component supply, RoHS-compliant packaging, and long-lifecycle support.

Supply support for MAX1806EUA08+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX1806 belongs to Maxim's μMAX low-dropout regulator family, engineered for portable and space-constrained systems demanding high accuracy, low quiescent current, and robust protection features at sub-1V output voltages.

FAQ

What is the maximum continuous output current of the MAX1806EUA08+T?

The MAX1806EUA08+T delivers a guaranteed 500mA RMS output current across its operating temperature range (-40°C to +85°C). This rating assumes proper thermal management via the exposed pad and adequate input-to-output voltage differential - for example, ≥175mV above 0.8V (i.e., VIN ≥ 0.975V) at full load. Short-circuit current limit ranges from 700mA to 2300mA depending on conditions.

Does the MAX1806EUA08+T require external resistors to set its output voltage?

No - the MAX1806EUA08+T is factory-configured for a fixed 0.8V output. Its SET pin is internally referenced to 800mV and must be connected to GND to activate preset mode. External resistors are only needed if using the adjustable variant (e.g., MAX1806EUAxx+ with different suffixes); the MAX1806EUA08+T operates exclusively in fixed-output configuration.

How does the POK (Power-OK) output function on the MAX1806EUA08+T?

The POK pin on the MAX1806EUA08+T is an open-drain, active-low output that goes high-impedance when V_OUT reaches ≥93% of its nominal 0.8V value, and pulls low otherwise. It requires a 100kΩ pullup resistor to V_OUT. During shutdown, POK is forcibly held low regardless of output voltage - enabling reliable power sequencing and fault detection in systems using the MAX1806EUA08+T.

Can the MAX1806EUA08+T operate from a 2.25V input while delivering 0.8V at 500mA?

Yes - the MAX1806EUA08+T is specified to operate with input voltages as low as 2.25V. At 500mA load and 0.8V output, its typical dropout is 175mV, meaning VIN = 0.975V would theoretically suffice. However, 2.25V input provides ample margin for line regulation, load transients, and temperature drift - ensuring stable regulation even under worst-case conditions across the full -40°C to +85°C range.

What package type and thermal requirements apply to the MAX1806EUA08+T?

The MAX1806EUA08+T uses an 8-pin power-μMAX package with an exposed metal thermal pad on the underside. To meet its 1.3W power dissipation rating and avoid thermal shutdown, the pad must be soldered to a large PCB ground plane or copper area using multiple vias. Without this connection, junction temperature rise exceeds safe limits under 500mA load - the MAX1806EUA08+T's thermal performance is critically dependent on proper pad implementation.