Analog Devices Inc./Maxim Integrated MAX6429KQUR+T

Overview

MAX6429KQUR+T from Maxim Integrated is a factory-trimmed, single-output, low-power battery monitor IC for Li+ and multi-cell alkaline/NiMH/NiCd systems. It features a fixed low-threshold of 1.9V (±2.5%), high-threshold of 2.6V (±2.5%), 140ms minimum LBO timeout, 1µA typical supply current, and operates from 1.0V to 5.5V. It is used in portable medical devices and MP3 players to trigger low-power mode before system shutdown.

For engineers reviewing the MAX6429KQUR+T datasheet, MAX6429KQUR+T pinout, MAX6429KQUR+T application, or MAX6429KQUR+T equivalent, this page delivers verified threshold values, SOT23-3 package details, push-pull LBO logic behavior, guaranteed operation down to 1.0V supply, and direct alternatives with documented threshold and output configuration differences.

Technical Context

The MAX6429KQUR+T implements a dual-comparator architecture with internal 615mV reference and hysteresis timing logic to generate a single active-low push-pull LBO signal. Its factory-trimmed thresholds eliminate external resistors and support precise battery state detection across -40°C to +85°C.

It asserts LBO when BATT falls below 1.9V and deasserts only after BATT rises above 2.6V and remains stable for ≥140ms - preventing false triggers during transient voltage recovery. The device draws just 1µA at 3.7V and guarantees valid LBO logic state even at BATT = 1.0V.

Key Specifications

Pinout & Package

SOT23-3 package: ultra-compact surface-mount outline with 0.95mm pitch, lead-free (RoHS-compliant), rated for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6429KQUR+T, MAX6428KRUR+T raises both thresholds by 100mV for less aggressive power management, while MAX6427DHUR+T lowers them by 300mV to accommodate lower-voltage chemistries - all retain identical SOT23-3 footprint and push-pull drive.

Availability

MAX6429KQUR+T is available at Aetrix Electronics and suitable for portable medical devices, MP3 players, and pagers requiring stable component supply with long-term lifecycle assurance and RoHS-compliant packaging.

Supply support for MAX6429KQUR+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, medical, and consumer markets.

The MAX6427–MAX6438 family was engineered specifically for ultra-low-power battery state monitoring in space-constrained portable electronics, emphasizing threshold accuracy, sub-µA quiescent current, and robust transient immunity.

FAQ

What is the exact low-battery threshold voltage of the MAX6429KQUR+T?

The MAX6429KQUR+T has a factory-trimmed low-threshold voltage (VLTH) of 1.9V with ±2.5% tolerance over temperature. This value is laser-trimmed during production and does not require external resistor networks. The MAX6429KQUR+T uses this threshold to assert its active-low push-pull LBO output when the battery voltage falls below 1.9V.

Does the MAX6429KQUR+T require external components to set its thresholds?

No, the MAX6429KQUR+T does not require external components. It belongs to the factory-trimmed subgroup (MAX6427–MAX6432) and integrates precise 1.9V/2.6V thresholds internally. Unlike adjustable versions (e.g., MAX6433–MAX6438), the MAX6429KQUR+T operates with zero external passives - simplifying layout and improving reliability in compact designs.

What is the function of the LBO pin on the MAX6429KQUR+T?

The LBO pin on the MAX6429KQUR+T is an active-low push-pull output that drives to GND when BATT < 1.9V and to BATT when BATT > 2.6V (after 140ms timeout). It interfaces directly with microcontroller NMI or GPIO pins without pull-up resistors. This behavior is confirmed in the MAX6429KQUR+T pin description and functional diagram.

Can the MAX6429KQUR+T operate down to 1.0V battery voltage?

Yes, the MAX6429KQUR+T guarantees valid LBO logic state down to BATT = 1.0V, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Its internal circuitry remains functional and produces correct LBO assertion/deassertion even at end-of-discharge voltage - a key differentiator for deep-discharge Li+ and alkaline systems.

What package type and dimensions does the MAX6429KQUR+T use?

The MAX6429KQUR+T uses the SOT23-3 package: 2.92mm × 1.3mm body size, 0.95mm pin pitch, and 1.02mm maximum height. It is lead-free (RoHS-compliant), supplied in tape-and-reel, and rated for -40°C to +85°C operation. This matches the ordering information and package outline referenced in the MAX6429KQUR+T datasheet.