Analog Devices Inc./Maxim Integrated MAX6349SPUT+T

Overview

MAX6349SPUT+T from Maxim Integrated is a 150mA, low-dropout linear voltage regulator with integrated microprocessor reset circuit, preset +2.5V output, -5% reset threshold, and active-low open-drain RESET output in SOT23-6 package. It consumes only 25µA quiescent current, achieves 180mV dropout at 100mA load, and supports manual reset input (MR) for system-level reset initiation - ideal for USB devices and cellular telephones requiring stable, low-power supply supervision.

For engineers reviewing the MAX6349SPUT+T datasheet, MAX6349SPUT+T pinout, MAX6349SPUT+T application, or MAX6349SPUT+T equivalent, key selection criteria include its fixed +2.5V output, -5% reset tolerance, MR input compatibility, 1µF minimum output capacitance requirement, and thermal/short-circuit protection - all critical for battery-powered portable designs where supply integrity and board space are constrained.

Technical Context

The MAX6349SPUT+T integrates a P-channel MOSFET LDO regulator core with a precision 1.23V internal reference shared by both regulation and reset functions. Its feedback path auto-selects between preset mode (SET = GND) and adjustable mode (external resistor divider), enabling fixed +2.5V operation without external components.

The reset supervisor monitors VOUT continuously, asserting open-drain RESET when voltage falls below 2.375V (−5% of 2.5V), holding it low for ≥100ms after recovery. The MR input provides asynchronous reset assertion independent of VOUT status, with 20kΩ internal pullup to OUT and 120ns glitch rejection - supporting reliable manual or logic-initiated resets in noisy environments.

Key Specifications

Pinout & Package

MAX6349SPUT+T is housed in a 6-pin SOT23-6 package with exposed pad for thermal dissipation. GND serves as both electrical reference and heatsink; soldering to a large copper area improves thermal performance under 150mA load.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6349SPUT+T, MAX6329SUT+T removes MR but adds shutdown control, while TPS3808G125DBVR trades integration for flexibility - making MAX6349SPUT+T optimal for space-constrained, MR-dependent portable systems needing single-chip +2.5V supply supervision.

Availability

MAX6349SPUT+T is available at Aetrix Electronics and suitable for USB devices, cellular telephones, and palm top computers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6349SPUT+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 in industrial, automotive, and consumer systems.

The MAX6349SPUT+T belongs to Maxim's micropower LDO-with-supervisor product line, engineered specifically for battery-powered portable equipment demanding ultra-low IQ, integrated reset, and minimal external components.

FAQ

What is the exact output voltage tolerance of the MAX6349SPUT+T?

The MAX6349SPUT+T delivers +2.5V output with ±3.0% accuracy over the full operating temperature range (0°C to +85°C) and input voltage range (2.5V to 5.5V). This specification is guaranteed by design and applies under load currents from 0 to 150mA, ensuring reliable operation for 2.5V logic families and USB PHY interfaces.

Does the MAX6349SPUT+T require an external pullup resistor on the RESET pin?

Yes, the MAX6349SPUT+T features an open-drain active-low RESET output, which requires an external pullup resistor to VOUT or another appropriate supply rail. Typical values range from 10kΩ to 100kΩ depending on bus capacitance and rise-time requirements. The internal circuitry does not provide pullup - omission will result in undefined reset signaling.

Can the MAX6349SPUT+T be used with a 1µF ceramic output capacitor?

Yes, the MAX6349SPUT+T is fully stable with a 1µF X7R or X5R ceramic capacitor on the OUT pin, as specified in the datasheet. This value meets minimum stability requirements across temperature and load conditions up to 150mA, enabling compact, low-ESR filtering without additional compensation components.

What is the function of the MR pin on the MAX6349SPUT+T?

The MR (Manual Reset) pin on the MAX6349SPUT+T is an active-low input that forces the RESET output low regardless of VOUT status. When pulled low (e.g., by a momentary switch to GND), it initiates a full reset sequence with ≥100ms timeout after release - enabling user-triggered or test-mode resets without affecting regulator operation.

How does the MAX6349SPUT+T handle reverse voltage conditions?

The MAX6349SPUT+T incorporates reverse leakage protection that disables the internal pass transistor when VOUT exceeds VIN, eliminating current flow from OUT to IN. This allows safe operation with auxiliary backup supplies (e.g., coin cell) without external blocking diodes, and guarantees zero reverse leakage current per datasheet specifications.