Analog Devices Inc./Maxim Integrated MAX6469UT28AD3+T

Overview

MAX6469UT28AD3+T from Maxim Integrated is a 300mA low-dropout linear regulator with integrated microprocessor reset circuit, fixed 2.8V output, -7.5% reset threshold, and 150ms minimum reset timeout. It operates from 2.5V to 5.5V input, delivers ±2.0% output accuracy over -40°C to +85°C, and consumes only 82µA quiescent current. Designed for battery-powered portable equipment, it powers microprocessors in handheld instruments and Bluetooth modules while ensuring safe boot sequencing.

For engineers reviewing the MAX6469UT28AD3+T datasheet, MAX6469UT28AD3+T pinout, MAX6469UT28AD3+T application, or MAX6469UT28AD3+T equivalent, key selection considerations include its SOT23-6 package, active-low push-pull RESET output, SHDN-controlled shutdown (0.1µA), dropout voltage of 137mV at 300mA (VOUT = 2.8V), and integrated reverse-current protection.

Technical Context

The MAX6469UT28AD3+T integrates a precision LDO core and a tightly coupled reset supervisor sharing the same reference voltage. Its regulator uses a PMOS pass device enabling low dropout (137mV @ 300mA, VOUT = 2.8V) and ultra-low ground current (82µA). The reset circuit monitors VOUT directly and asserts active-low RESET when output falls below 92.5% of nominal (–7.5% tolerance), with guaranteed 150ms minimum timeout after recovery.

It features active-low SHDN control that disables the pass transistor, reference, and control circuitry-reducing supply current to 0.1µA-and includes built-in thermal shutdown (180°C trip, 20°C hysteresis), short-circuit protection, and reverse OUT-to-IN leakage limiting (<0.01µA). Pin 3 (SHDN) and Pin 4 (RESET) are functionally dedicated and electrically isolated from feedback paths.

Key Specifications

Pinout & Package

MAX6469UT28AD3+T is housed in a 6-pin SOT23-6 package with exposed pad (EP) not present - consistent with MAX6469/MAX6470 family designation. The package supports high thermal dissipation via GND pin soldered to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS76328QDBVRQ1 and ADM6315-28D3ARTZ-RL, the MAX6469UT28AD3+T uniquely integrates 300mA LDO regulation, –7.5% reset threshold, 150ms timeout, SHDN control, and reverse-current blocking in one SOT23-6 package - reducing solution size, BOM count, and boot reliability risk.

Availability

MAX6469UT28AD3+T is available at Aetrix Electronics and suitable for handheld instruments, Bluetooth modules, and notebook subsystems requiring stable component supply with long-term manufacturability and RoHS-compliant packaging.

Supply support for MAX6469UT28AD3+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, automotive, and portable applications.

The MAX6469–MAX6484 product line delivers highly integrated, ultra-low-IQ LDOs with embedded reset supervision - targeting battery-constrained systems where board space, power efficiency, and boot reliability are critical.

FAQ

What is the exact output voltage and tolerance of the MAX6469UT28AD3+T?

The MAX6469UT28AD3+T provides a fixed 2.8V output with ±2.0% accuracy over the full –40°C to +85°C operating temperature range. This specification is guaranteed across load currents from 1mA to 300mA and input voltages from 2.5V to 5.5V. The "28" in the part number explicitly denotes the 2.8V preset output, and the device uses internal resistor dividers - no external components are needed to set this voltage. MAX6469UT28AD3+T maintains this accuracy without requiring calibration or trimming.

Does the MAX6469UT28AD3+T include shutdown functionality, and how is it controlled?

Yes, the MAX6469UT28AD3+T includes an active-low shutdown feature controlled via Pin 3 (SHDN). When SHDN is pulled low, the regulator disables its pass transistor, reference, and control circuitry, reducing total supply current to 0.1µA (typical). For normal operation, SHDN must be tied to IN (or a logic-high voltage ≥0.7×VIN). This function is confirmed in the Electrical Characteristics table and Pin Description section of the MAX6469UT28AD3+T datasheet.

What type of RESET output does the MAX6469UT28AD3+T provide, and what is its timeout duration?

The MAX6469UT28AD3+T provides an active-low push-pull RESET output with a minimum timeout duration of 150ms, as indicated by the "D3" suffix in the part number. This RESET signal asserts low during power-up, brownout, or SHDN activation and remains low for at least 150ms after VOUT rises above the –7.5% reset threshold (2.59V). The push-pull structure eliminates the need for an external pull-up resistor, simplifying design. MAX6469UT28AD3+T does not offer open-drain RESET in this variant.

Can the MAX6469UT28AD3+T be used with a backup supercapacitor, and how does it behave during input removal?

Yes, the MAX6469UT28AD3+T supports backup operation: when IN is removed, its reverse OUT-to-IN leakage is limited to 0.01µA (typ), preventing discharge of backup sources. With SHDN pulled up to VOUT (e.g., via external diode), the device maintains ~40µA OUT-to-GND current, allowing supercapacitors to sustain VOUT during battery replacement. RESET asserts during this state, placing downstream logic in known low-power mode. This behavior is documented in the Reverse Leakage Protection section of the MAX6469UT28AD3+T datasheet.

What protection features are built into the MAX6469UT28AD3+T?

The MAX6469UT28AD3+T integrates thermal shutdown (180°C trip, 20°C hysteresis), short-circuit current limiting (450mA min), reverse OUT-to-IN current protection (<0.01µA), and input undervoltage lockout (2.25V to 2.47V). These functions operate autonomously without external components. The thermal and current protections safeguard against continuous overload, while the UVLO prevents erratic operation during weak battery conditions. All are verified in the Absolute Maximum Ratings and Electrical Characteristics tables for MAX6469UT28AD3+T.