Analog Devices Inc./Maxim Integrated MAX6434UK+T

Overview

MAX6434UK+T from Maxim Integrated is a user-adjustable, single-output, low-power battery monitor IC with internal 615mV reference, 140ms LBO timeout, and open-drain active-low LBO output. It monitors battery voltage via external resistor-divider on LTHIN/HTHIN inputs and operates from 1.6V to 5.5V supply. Designed for portable medical devices and MP3 players using single-cell alkaline/NiMH or Li+ batteries.

For engineers reviewing the MAX6434UK+T datasheet, MAX6434UK+T pinout, MAX6434UK+T application, or MAX6434UK+T equivalent, this page delivers verified electrical specs, package mapping, functional role in battery-state signaling, and real-world selection guidance for low-quiescent-current power management.

Technical Context

The MAX6434UK+T implements dual-comparator hysteresis architecture with internal 615mV reference to determine battery state: LBO asserts when LTHIN falls below VLTHIN− (615mV), and deasserts only after HTHIN rises above VHTHIN+ (615mV) for ≥140ms. Its high-impedance LTHIN/HTHIN inputs accept externally set thresholds via resistor divider, enabling precise noise-immune trip points down to 0.62V.

It features push-pull or open-drain LBO output logic options - MAX6434UK+T uses open-drain active-low configuration referenced to VDD, allowing interface with higher-voltage microcontrollers while operating directly from battery or regulated supply. Guaranteed valid LBO logic state persists down to BATT = 1.0V.

Key Specifications

Pinout & Package

MAX6434UK+T is housed in a lead-free 5-pin SOT23-5 package (JEDEC MO-178AA), 2.9mm × 1.6mm × 1.1mm, with exposed pad for thermal performance. Pin 1 = VDD, Pin 2 = GND, Pin 3 = LBOL/LBO, Pin 4 = LTHIN, Pin 5 = HTHIN.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6433UK+T, MAX6434UK+T adds independent HTHIN control for precise hysteresis tuning; compared with TLV7031DBVR, it integrates timing, reference, and logic - reducing component count by 4× and guaranteeing 140ms timeout without calibration.

Availability

MAX6434UK+T is available at Aetrix Electronics and suitable for portable medical devices, MP3 players, pagers, and electronic toys requiring stable component supply with guaranteed long-term lifecycle support.

Supply support for MAX6434UK+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 analog and mixed-signal ICs for power, sensing, and interface applications.

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

FAQ

What is the primary function of the MAX6434UK+T in a battery-powered system?

The MAX6434UK+T serves as a precision, low-power battery monitor that detects when supply voltage crosses user-defined low- and high-threshold levels. It asserts an open-drain LBO signal when voltage falls below the LTHIN-set point and holds it for ≥140ms, ensuring stable detection. This enables reliable low-battery warnings and controlled system power-down in devices like portable medical sensors and MP3 players - all while consuming just 1µA typical supply current.

How does the MAX6434UK+T achieve hysteresis without external components?

The MAX6434UK+T achieves hysteresis through its dual-comparator architecture and internal 615mV reference. The LTHIN input triggers LBO assertion when its voltage falls below 615mV; the HTHIN input controls deassertion only after rising above 615mV for ≥140ms. By configuring separate resistor-divider ratios on LTHIN and HTHIN, users set distinct trip points - e.g., 2.4V (LTHIN) and 2.52V (HTHIN) - creating a 5% hysteresis band that prevents output chatter during battery recovery.

Can the MAX6434UK+T operate from a single 1.5V alkaline cell?

No - the MAX6434UK+T requires a minimum VDD of 1.6V per its Absolute Maximum Ratings and Electrical Characteristics tables. While it can monitor down to 0.62V via external divider, its own supply must be ≥1.6V. For true 1.5V operation, a boost regulator or alternative IC like MAX6433UK+T (with same VDD min) paired with careful divider design is required. Operating below 1.6V risks undefined LBO behavior and invalid specification compliance.

What is the purpose of the 140ms timeout period in the MAX6434UK+T?

The 140ms minimum timeout ensures the LBO output remains asserted long enough to prevent false deassertion during brief voltage recoveries - such as those caused by load removal or transient spikes. This guarantees that downstream logic (e.g., microcontroller interrupt or PMIC enable) receives a stable, debounced signal before initiating power-state transitions. The timeout is internally generated and temperature-compensated, eliminating need for external RC networks and improving system reliability across –40°C to +85°C.

Is the MAX6434UK+T pin-compatible with other members of the MAX6427–MAX6438 family?

MAX6434UK+T is pin-compatible with MAX6433UK+T and MAX6435UK+T (all SOT23-5), sharing identical VDD, GND, LBO, LTHIN, and HTHIN pin assignments. However, it is not compatible with SOT23-3 (e.g., MAX6427) or SOT143-4 (e.g., MAX6430) variants due to differing pin counts and functions. Always verify pin mapping against the specific variant's Pin Configuration diagram - MAX6434UK+T uses VDD instead of BATT and includes both LTHIN and HTHIN, unlike single-threshold or dual-output versions.