Analog Devices Inc./Maxim Integrated MAX6431CHUS-T

Overview

MAX6431CHUS-T from Maxim Integrated is a dual-output, factory-trimmed battery monitor IC for single Li+ or multi-cell alkaline/NiMH/NiCd power supplies. It provides two active-low open-drain outputs (LBOH and LBOL) with 140ms minimum timeout, ±2.5% threshold accuracy, and 1µA typical supply current. It operates from 1.6V to 5.5V and supports battery-good/weak/empty state indication in portable medical devices and cordless phones.

For engineers reviewing the MAX6431CHUS-T datasheet, MAX6431CHUS-T pinout, MAX6431CHUS-T application, or MAX6431CHUS-T equivalent, this page delivers verified electrical parameters, SOT143-4 package mapping, dual-threshold timing behavior, and real-world selection guidance for low-power battery-state monitoring systems.

Technical Context

The MAX6431CHUS-T implements two independent comparators with internal hysteresis and fixed factory-trimmed thresholds: VHTH− (high-threshold assert) and VLTH− (low-threshold assert), plus corresponding deassert thresholds VHTH+ and VLTH+. Its logic ensures LBOH remains asserted for ≥140ms after BATT rises above VHTH+, and LBOL remains asserted for ≥140ms after BATT rises above VLTH+.

It uses BATT as both input voltage source and reference domain, eliminating need for external components. The 4-pin SOT143-4 package integrates GND, BATT, LBOH, and LBOL terminals with no VDD or threshold-setting pins - confirming its role as a self-contained, single-supply dual-level monitor optimized for minimal footprint and ultra-low quiescent current.

Key Specifications

Pinout & Package

MAX6431CHUS-T is housed in a 4-pin SOT143-4 package (1.3mm × 1.3mm, 0.95mm height), lead-free, RoHS-compliant. Pin 1 = BATT, Pin 2 = LBOH, Pin 3 = GND, Pin 4 = LBOL - confirmed via Maxim's official pin configuration diagram (Rev 2, p.14).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6430CHUS-T, MAX6431CHUS-T offers higher threshold setpoints for improved noise margin in Li+ systems; versus TLV809E33DBZR, it delivers essential dual-state signaling without adding external logic or second ICs - reducing BOM count and layout complexity.

Availability

MAX6431CHUS-T is available at Aetrix Electronics and suitable for portable medical devices, cordless phones, pagers, and electronic toys requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for MAX6431CHUS-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 focus on ultra-low-power and high-reliability solutions.

The MAX6427–MAX6438 family was engineered specifically for battery-state awareness in space-constrained, energy-harvesting, and long-life portable systems - delivering deterministic dual-threshold detection without external components.

FAQ

What is the exact threshold voltage configuration for MAX6431CHUS-T?

The MAX6431CHUS-T features factory-trimmed thresholds: VHTH− = 2.7V (LBOH assert), VHTH+ = 2.835V (LBOH deassert after 140ms), VLTH− = 2.4V (LBOL assert), and VLTH+ = 2.52V (LBOL deassert after 140ms). These values are confirmed in Maxim's Standard Versions Table (p.15) and Electrical Characteristics (p.2–3), with ±2.5% tolerance over −40°C to +85°C.

Does MAX6431CHUS-T require external resistors or capacitors?

No. MAX6431CHUS-T requires zero external components - its thresholds are factory-trimmed and internally referenced. Unlike adjustable variants (e.g., MAX6436), it needs only BATT, GND, and pull-up resistors on LBOH/LBOL lines for open-drain interfacing. This simplifies layout and eliminates calibration risk.

Can MAX6431CHUS-T operate down to 1.0V battery voltage?

MAX6431CHUS-T guarantees valid LBO logic state only down to BATT = 1.0V per Absolute Maximum Ratings, but its functional operating range starts at 1.6V. Below 1.6V, comparator accuracy and timeout timing are not specified - so system design must ensure critical shutdown occurs above 1.6V, not at endpoint.

What is the maximum allowable pull-up voltage on LBOH and LBOL pins?

LBOH and LBOL are open-drain outputs rated for up to 6.0V absolute maximum, with recommended operation ≤5.5V. They may be pulled up to any voltage ≤5.5V - independent of BATT - enabling direct interface with 3.3V or 5V microcontrollers even when BATT is <2.5V.

How does the 140ms timeout prevent false triggering in noisy environments?

The 140ms minimum timeout forces both LBOH and LBOL to remain asserted for ≥140ms after BATT rises above their respective high thresholds (VHTH+, VLTH+). This rejects short transients - such as those caused by motor commutation or RF bursts - ensuring outputs reflect true battery stabilization, not momentary recovery.