Analog Devices Inc./Maxim Integrated MAX6429LQUR+T

Overview

MAX6429LQUR+T from Maxim Integrated is a factory-trimmed, single-output, low-power battery monitor IC for single Li+ or multi-cell alkaline/NiMH/NiCd systems. It features a fixed low-threshold of 2.9V (±2.5%), high-threshold of 3.0V (±2.5%), 140ms minimum LBO timeout, 1µA typical supply current, and push-pull active-low LBO output - used to trigger system low-power mode when battery voltage drops below threshold.

For engineers reviewing the MAX6429LQUR+T datasheet, MAX6429LQUR+T pinout, MAX6429LQUR+T application, or MAX6429LQUR+T equivalent, this device serves as a precision, hysteresis-equipped battery health indicator in space-constrained portable electronics where ultra-low quiescent current and guaranteed logic state down to 1.0V are critical selection criteria.

Technical Context

The MAX6429LQUR+T implements a dual-comparator architecture with internal 615mV reference and timing circuitry to enforce a minimum 140ms deassertion delay after voltage recovery, preventing false wakeups during transient load-induced dips. Its fixed thresholds are laser-trimmed at wafer level, eliminating external resistors and calibration effort.

It operates from 1.0V to 5.5V supply (BATT), guarantees valid LBO logic state down to BATT = 1.0V, and remains functional across –40°C to +85°C. The push-pull LBO output drives directly into microcontroller NMI or enable inputs without pull-up, supporting immediate system-level response to battery degradation.

Key Specifications

Pinout & Package

SOT23-3 package (3-pin, 1.4mm × 1.0mm × 0.9mm), lead-free, RoHS-compliant, tape-and-reel packaging.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6428LQUR+T, the MAX6429LQUR+T delays low-battery assertion until deeper discharge, extending runtime; compared with TLV7031DBVR, it delivers turnkey accuracy, ultra-low IQ, and integrated timing - reducing design cycle time and validation risk.

Availability

MAX6429LQUR+T is available at Aetrix Electronics and suitable for portable medical devices, electronic toys, MP3 players, and PDAs requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for MAX6429LQUR+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 in industrial, automotive, and consumer markets.

The MAX6427–MAX6438 family was engineered specifically for ultra-low-power battery monitoring in compact portable electronics, delivering factory-trimmed accuracy, sub-µA operation, and integrated hysteresis/timing to eliminate external components.

FAQ

What is the exact low-battery threshold voltage of the MAX6429LQUR+T?

The MAX6429LQUR+T has a factory-trimmed low-threshold voltage (VLTH) of 2.9V with ±2.5% tolerance over temperature. This value is laser-trimmed during production and does not require external calibration. The corresponding high-threshold (VHTH) is 3.0V, establishing a 100mV hysteresis band to prevent output oscillation near the trip point. These values are specified in the Electrical Characteristics table of the MAX6429LQUR+T datasheet under "FACTORY-FIXED THRESHOLDS".

Does the MAX6429LQUR+T require external resistors to set its thresholds?

No, the MAX6429LQUR+T does not require external resistors. It belongs to the factory-trimmed subgroup (MAX6427–MAX6432) of the MAX6427–MAX6438 family and integrates precision voltage references and comparator thresholds directly onto the die. All threshold voltages are laser-trimmed at wafer test, enabling immediate use with only BATT, GND, and LBO connections - no resistor dividers, no calibration, and no additional passive components needed.

What is the function and timing behavior of the LBO output on the MAX6429LQUR+T?

The LBO output of the MAX6429LQUR+T is an active-low push-pull signal that asserts (goes low) when the BATT voltage falls below 2.9V and remains asserted for a minimum of 140ms after BATT rises above 3.0V. This timeout ensures stable voltage recovery before deassertion. The output can directly drive microcontroller interrupt pins or enable inputs without external pull-up, sinking up to 3.2mA at 4.5V supply - a key feature confirmed in the MAX6429LQUR+T Electrical Characteristics table.

Can the MAX6429LQUR+T operate down to 1.0V battery voltage?

Yes, the MAX6429LQUR+T guarantees valid LBO logic state (defined HIGH/LOW levels) down to BATT = 1.0V, as explicitly stated in the datasheet's "Features" section and verified in Absolute Maximum Ratings and Electrical Characteristics. This capability allows safe, predictable system shutdown sequencing even at near-exhausted battery voltage - a critical requirement for portable medical and safety-critical devices using the MAX6429LQUR+T.

What package type and pin configuration does the MAX6429LQUR+T use?

The MAX6429LQUR+T uses the 3-pin SOT23-3 package (1.4mm × 1.0mm footprint) with top-mark "LQ" and pinout: Pin 1 = BATT, Pin 2 = LBO, Pin 3 = GND. This is confirmed in the "Pin Configurations" section and "Ordering Information" table of the MAX6429LQUR+T datasheet, and matches the mechanical drawing labeled "SOT23 L.EPS" (Package Outline 21-0051). The "+T" suffix denotes lead-free, RoHS-compliant tape-and-reel packaging.