Analog Devices Inc./Maxim Integrated MAX6429LSUR+T

Overview

The MAX6429LSUR+T from Maxim Integrated is a factory-trimmed, single-output, low-power battery monitor IC for lithium-ion and alkaline/NiMH/NiCd battery systems. It features a fixed low-threshold of 2.0V (±2.5%), high-threshold of 2.7V (±2.5%), 140ms minimum LBO timeout, 1µA typical supply current, and operates from 1.0V to 5.5V. It delivers active-low push-pull LBO output to signal battery depletion in portable medical devices and MP3 players.

For engineers reviewing the MAX6429LSUR+T datasheet, MAX6429LSUR+T pinout, MAX6429LSUR+T application, or MAX6429LSUR+T equivalent, this page provides verified functional specifications, validated SOT23-3 package mapping, confirmed threshold hysteresis behavior, and real-world timing characteristics - all directly traceable to Maxim's official documentation.

Technical Context

The MAX6429LSUR+T implements a precision comparator-based monitoring architecture with internal 615mV reference and built-in hysteresis logic. Its fixed thresholds are laser-trimmed at wafer level, eliminating external resistor networks and ensuring ±2.5% accuracy over –40°C to +85°C.

It asserts its push-pull LBO output when battery voltage falls below 2.0V and deasserts only after voltage rises above 2.7V and remains stable for ≥140ms - preventing false triggers during transient load recovery. The device guarantees valid LBO logic state down to BATT = 1.0V and draws just 1µA typical quiescent current.

Key Specifications

Pinout & Package

MAX6429LSUR+T is housed in a lead-free 3-pin SOT23-3 package (JEDEC MO-178AA), with 1.3mm × 2.9mm footprint and 1.45mm max height. Pin 1 = BATT, Pin 2 = LBO, Pin 3 = GND - no VDD or threshold adjustment pins required due to factory-trimmed architecture.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery monitor applications.

Compared with MAX6429LSUR+T, MAX6428MSUR+T offers lower trip points for earlier low-battery warning in NiMH systems, while TLV809K33DBZR provides ultra-low current but lacks hysteresis, timeout, and dual-threshold functionality essential for robust battery state management.

Availability

MAX6429LSUR+T is available at Aetrix Electronics and suitable for portable medical devices, MP3 players, and pagers requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX6429LSUR+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, sensing, and interface applications, with emphasis on low-power, high-reliability solutions.

The MAX6427–MAX6438 family was engineered specifically for battery-powered systems requiring accurate, low-quiescent-current voltage monitoring with configurable hysteresis and robust noise immunity.

FAQ

What is the exact low-battery threshold voltage of the MAX6429LSUR+T?

The MAX6429LSUR+T has a factory-trimmed low-threshold voltage (VLTH) of 2.0V with ±2.5% tolerance over –40°C to +85°C. This value is laser-trimmed during manufacturing and does not require external calibration. The corresponding high-threshold (VHTH) is 2.7V, yielding 700mV of hysteresis - a key design feature to prevent output chattering during battery voltage fluctuations.

Does the MAX6429LSUR+T require external resistors to set its thresholds?

No, the MAX6429LSUR+T does not require external resistors. As a factory-trimmed variant in the MAX6427–MAX6432 series, it integrates precise threshold references internally. Its 2.0V/2.7V thresholds are set at wafer level, enabling direct connection to BATT and GND with only the LBO output needing routing - significantly simplifying schematic design and reducing bill-of-materials count.

What is the function of the LBO pin on the MAX6429LSUR+T?

The LBO pin on the MAX6429LSUR+T is an active-low push-pull output that asserts (drives low) when the BATT voltage falls below 2.0V and remains asserted for at least 140ms after BATT rises above 2.7V. It can directly drive microcontroller interrupt inputs or enable/disable logic without external pull-up resistors, supporting sink currents up to 3.2mA at 4.5V supply.

Can the MAX6429LSUR+T operate down to 1.0V battery voltage?

Yes, the MAX6429LSUR+T guarantees valid LBO logic state operation down to BATT = 1.0V - a critical feature for end-of-life battery detection. While its specified operating range starts at 1.0V, the device maintains functional comparator behavior and correct output polarity throughout this range, enabling reliable last-chance shutdown signaling in deeply discharged Li+ or alkaline systems.

What package type and pin count does the MAX6429LSUR+T use?

The MAX6429LSUR+T uses a 3-pin SOT23-3 package (JEDEC MO-178AA), with pinout: Pin 1 = BATT, Pin 2 = LBO, Pin 3 = GND. This compact 1.3mm × 2.9mm surface-mount package supports automated assembly and is lead-free compliant per the "+T" suffix, meeting RoHS and JEDEC MSL-1 handling requirements.