Analog Devices Inc./Maxim Integrated MAX6349TLUT+T

Overview

MAX6349TLUT+T from Maxim Integrated is a 150mA low-dropout linear voltage regulator with integrated microprocessor reset circuit, preset +3.3V output, -5% reset threshold, push-pull active-high RESET output, and manual reset (MR) input. It consumes only 25µA quiescent current, features 180mV dropout at 100mA, and operates from 2.5V to 5.5V input - ideal for battery-powered USB devices and handheld instruments.

For engineers reviewing the MAX6349TLUT+T datasheet, MAX6349TLUT+T pinout, MAX6349TLUT+T application, or MAX6349TLUT+T equivalent, key selection criteria include its fixed +3.3V output, 100ms minimum reset timeout, MR-triggered reset assertion while VOUT remains in spec, thermal/short-circuit protection, and SOT23-6 package compatibility with space-constrained portable designs.

Technical Context

The MAX6349TLUT+T integrates a P-channel MOSFET LDO regulator core with a precision 1.23V internal reference shared by both regulation and reset functions. Its reset supervisor monitors VOUT against a -5% threshold (2.92V to 3.185V at +3.3V output) and asserts RESET for ≥100ms after recovery, ensuring stable power and clock settling before processor boot.

It implements manual reset via MR pin - a logic-low pulse ≥1µs forces reset regardless of VOUT status, with internal 20kΩ pullup to OUT and 120ns glitch rejection. Unlike the MAX6329, it lacks shutdown but adds robust reverse leakage protection and zero-input-reverse-current behavior during backup-battery operation.

Key Specifications

Pinout & Package

MAX6349TLUT+T is housed in a 6-pin SOT23-6 package with exposed pad for thermal dissipation. GND serves dual role as electrical ground and heatsink; recommended soldering to large copper area or ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO-with-reset applications.

Compared with MAX6329TLUT+T, MAX6349TLUT+T trades shutdown for manual reset - enabling field-serviceable reboots without power cycle. Against TPS76333DBVR+TPS3809K33, MAX6349TLUT+T delivers tighter reset timing correlation, lower component count, and guaranteed -5% threshold tracking without calibration.

Availability

MAX6349TLUT+T is available at Aetrix Electronics and suitable for USB devices, handheld instrumentation, palm-sized computing, and PCMCIA card regulation requiring stable component supply across production lifecycles.

Supply support for MAX6349TLUT+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 and mixed-signal ICs for power management, sensing, and interface applications.

The MAX6329/MAX6349 family targets battery-powered portable electronics needing highly integrated, ultra-low-power voltage regulation with reliable power-on reset and manual intervention capability.

FAQ

What is the reset timeout duration for MAX6349TLUT+T?

The MAX6349TLUT+T provides a guaranteed minimum reset timeout of 100ms after VOUT rises above the -5% threshold or after MR transitions from low to high. Typical timeout is 200ms, and maximum is 300ms per datasheet Electrical Characteristics table. This ensures adequate stabilization time for microprocessor clocks and peripherals before release of the RESET signal.

Does MAX6349TLUT+T support adjustable output voltage?

No, MAX6349TLUT+T is factory-configured for fixed +3.3V output. The "TL" suffix denotes -5% reset threshold and push-pull active-high RESET; the "UT" indicates SOT23-6 package. Adjustable operation requires connecting SET to an external resistor divider - but MAX6349TLUT+T's internal feedback is trimmed for +3.3V, and SET must be tied to GND per datasheet Pin Description.

What is the function of the MR pin on MAX6349TLUT+T?

The MR (Manual Reset) pin on MAX6349TLUT+T is an active-low input that forces the RESET output high (due to push-pull active-high configuration) whenever MR is pulled below 0.2×VOUT. It remains asserted for ≥100ms after MR returns high. Internal 20kΩ pullup to OUT eliminates need for external resistor; a momentary switch from MR to GND provides reliable manual reset without debounce circuitry.

Can MAX6349TLUT+T operate with input voltage below 2.5V?

No, MAX6349TLUT+T has a specified input voltage range of +2.5V to +5.5V per Absolute Maximum Ratings and Electrical Characteristics tables. Operation below 2.5V is not characterized or guaranteed - regulation fails, reset behavior becomes unpredictable, and internal biasing may collapse. For sub-2.5V applications, consider alternative regulators such as MAX1725 or TPS780xx series.

Is thermal shutdown protection included in MAX6349TLUT+T?

Yes, MAX6349TLUT+T includes fully integrated thermal shutdown protection. When junction temperature exceeds +160°C, the pass transistor turns off. After cooling by ≥20°C hysteresis, the device automatically recovers. This protects MAX6349TLUT+T during sustained overload or poor PCB thermal design, and is documented in the Detailed Description and Electrical Characteristics sections of the datasheet.