Analog Devices Inc./Maxim Integrated MAX6428EHUR+T

Overview

MAX6428EHUR+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 2.8V (±2.5%), high-threshold of 3.5V (±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 for direct microprocessor NMI or system shutdown control in portable medical devices and pagers.

For engineers reviewing the MAX6428EHUR+T datasheet, MAX6428EHUR+T pinout, MAX6428EHUR+T application, or MAX6428EHUR+T equivalent, this page provides verified threshold values, SOT23-3 package mapping, LBO timing behavior, hysteresis specification, and real-world use cases with design-meaning context - all confirmed from Maxim's official datasheet Rev 2 (12/05).

Technical Context

The MAX6428EHUR+T implements a dual-comparator architecture with internal 615mV reference and precision hysteresis logic. Its fixed thresholds are laser-trimmed at wafer level: VLTH = 2.8V (falling edge trigger) and VHTH = 3.5V (rising edge deassertion), yielding 700mV total hysteresis. The 140ms timeout ensures stable voltage recovery before LBO deassertion.

It uses BATT as both power source and monitored input, eliminating external supply rails. The push-pull LBO output drives directly into microprocessor NMI or enable pins without pull-up resistors, and remains valid down to BATT = 1.0V - critical for deep-discharge detection in single-cell Li+ systems.

Key Specifications

Pinout & Package

MAX6428EHUR+T is housed in a lead-free 3-pin SOT23-3 package (JEDEC MO-178AA), with 1.3mm × 0.8mm footprint and 0.95mm height. Pin 1 = BATT, Pin 2 = LBO, Pin 3 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6427EHUR+T and TLV7031DBVR, MAX6428EHUR+T offers optimal balance of out-of-box accuracy (2.8V/3.5V), zero-component integration, and guaranteed sub-1.0V functional operation - making it the preferred choice for volume production of Li+-based portable devices.

Availability

MAX6428EHUR+T is available at Aetrix Electronics and suitable for portable medical devices, pagers, legacy cell phones, and electronic toys requiring stable component supply across extended product lifecycles and temperature ranges.

Supply support for MAX6428EHUR+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, medical, and consumer applications.

The MAX6427–MAX6438 family was designed specifically for ultra-low-power, single/dual-level battery state monitoring in space-constrained portable electronics - delivering factory-trimmed accuracy and integrated timeout logic without external components.

FAQ

What is the exact low-battery threshold voltage for MAX6428EHUR+T?

The MAX6428EHUR+T has a factory-trimmed low-threshold voltage (VLTH) of 2.8V ±2.5%, meaning it asserts the LBO output when the BATT voltage falls below 2.73V (min) and deasserts only after rising above 3.41V (min) with 140ms timeout. This value is laser-trimmed and documented in Maxim's datasheet Rev 2, Table 1, under "EH" suffix for single-cell Li+ applications.

Does MAX6428EHUR+T require external resistors or capacitors to operate?

No, MAX6428EHUR+T requires no external components. Its thresholds are factory-trimmed, and the 140ms timeout is implemented internally. Only BATT, GND, and LBO connections are needed - making it a true 3-pin plug-and-play solution for battery monitoring, unlike adjustable-threshold variants such as MAX6433UK-T.

Can MAX6428EHUR+T monitor a single alkaline cell?

Yes, MAX6428EHUR+T can monitor a single alkaline cell, though its 2.8V/3.5V thresholds are optimized for single Li+ (3.0–4.2V) or two alkaline (2.4–3.2V). For single alkaline (1.5–0.9V), the 2.8V threshold triggers very early - consider MAX6427DHUR+T (1.6V/2.3V) instead. MAX6428EHUR+T remains functional down to BATT = 1.0V with valid LBO logic.

What is the maximum sink current capability of the LBO output on MAX6428EHUR+T?

The push-pull LBO output of MAX6428EHUR+T sinks up to 3.2mA at VDD = 4.5V (VOL ≤ 0.4V), 1.2mA at VDD = 2.7V (VOL ≤ 0.3V), and 100µA at VDD = 1.6V (VOL ≤ 0.3V). This allows direct driving of microcontroller NMI inputs, LED drivers, or PMIC enable pins without external buffers.

Is MAX6428EHUR+T compatible with lead-free PCB assembly processes?

Yes, MAX6428EHUR+T is supplied in lead-free packaging (RoHS-compliant), indicated by the "+T" suffix. It supports standard Pb-free reflow profiles per JEDEC J-STD-020, with peak temperature up to +260°C and 60-second duration above liquidus - verified in Maxim's package documentation for SOT23-3.