Analog Devices Inc./Maxim Integrated MAX6400BS22-T

Overview

MAX6400BS22-T from Maxim Integrated is an ultra-low-power microprocessor supervisory circuit designed to monitor VCC supply voltage and assert a reset signal when voltage falls below 2.20V. It features active-low push-pull RESET output, factory-trimmed ±2.5% threshold accuracy over –40°C to +85°C, 100ms minimum reset timeout, and operates down to VCC = 1.0V - ideal for battery-backed portable systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6400BS22-T datasheet, MAX6400BS22-T pinout, MAX6400BS22-T application, or MAX6400BS22-T equivalent, key selection considerations include its 500nA typical supply current, UCSP-4 chip-scale package footprint, manual reset (MR) input with internal 50kΩ pullup, immunity to sub-200ns VCC transients, and guaranteed reset assertion at VCC ≥ 1.0V.

Technical Context

The MAX6400BS22-T integrates a precision bandgap reference comparator with factory-trimmed 2.20V reset threshold and 6.3mV hysteresis. Its internal timer ensures RESET remains asserted for ≥100ms after VCC rises above VTH, preventing premature processor release during power-up.

It supports manual reset via MR pin - a logic-low pulse ≥1µs initiates reset, which persists for the full tRP timeout after MR returns high. The push-pull output drives low to ≤0.4V at 1.6mA sink (VCC ≥ 2.1V), eliminating need for external pullup resistors.

Key Specifications

Pinout & Package

MAX6400BS22-T is housed in a 4-bump, 2mm × 2mm UCSP (Ultra-Compact Silicon Package) - a wafer-level chip-scale package with no leadframe, optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with TPS3123E12DBVR and ADM6315-23ARTZ-RL7, the MAX6400BS22-T delivers 3.6× lower supply current and a 70% smaller footprint, enabling longer battery life and denser layouts - but requires UCSP reflow process qualification and lacks SOT-23 pin compatibility.

Availability

MAX6400BS22-T is available at Aetrix Electronics and suitable for portable medical sensors, industrial data loggers, smart metering modules, and IoT edge nodes requiring stable component supply, long-lifecycle support, and consistent UCSP-4 packaging.

Supply support for MAX6400BS22-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, communications, and consumer applications.

The MAX6400–MAX6405 family was designed specifically for ultra-low-power microprocessor supervision in space- and energy-constrained portable electronics, emphasizing minimal ICC, small UCSP packaging, and robust reset timing under brownout conditions.

FAQ

What is the exact reset threshold voltage of MAX6400BS22-T and how tightly is it specified?

The MAX6400BS22-T has a nominal reset threshold of 2.20V, with a tolerance of ±2.5% over the full industrial temperature range (–40°C to +85°C). At +25°C, the typical value is 2.200V, with min/max of 2.167V/2.233V. This tight factory trimming eliminates need for external resistor networks and ensures predictable brownout behavior in battery-powered systems using the MAX6400BS22-T.

Does MAX6400BS22-T require external components to operate?

No, the MAX6400BS22-T requires no external components. It integrates a precision bandgap reference, comparator, reset timer, and push-pull output driver. The MR input includes a 50kΩ internal pullup resistor, and the active-low RESET output drives directly into a microcontroller reset pin without needing an external pullup - all essential supervision functions are self-contained within the MAX6400BS22-T.

Can MAX6400BS22-T function reliably when VCC drops below 2.0V?

Yes, the MAX6400BS22-T guarantees correct reset output logic state down to VCC = 1.0V. Its internal circuitry remains functional and asserts RESET low whenever VCC falls below 2.20V - even at 1.2V supply - making it suitable for applications where backup capacitors or depleted batteries sustain marginal voltage rails, ensuring safe shutdown before firmware corruption occurs in the MAX6400BS22-T monitored system.

What is the reset timeout duration of MAX6400BS22-T and is it adjustable?

The MAX6400BS22-T features a factory-set minimum reset timeout period of 100ms, with typical and maximum values of 185ms and 280ms respectively. This timeout is fixed and non-adjustable - implemented via on-chip RC timing - ensuring consistent, repeatable reset hold time across units and temperature without external capacitor dependencies, a key reliability feature of the MAX6400BS22-T.

How does the manual reset (MR) input behave on MAX6400BS22-T?

The MR input on MAX6400BS22-T is active-low with an internal 50kΩ pullup to VCC. A logic-low pulse ≥1µs on MR forces RESET low immediately and holds it for the full reset timeout period (≥100ms) after MR returns high. If left unconnected, MR remains high due to the internal pullup - no external components are needed, simplifying design and reducing risk of floating inputs in the MAX6400BS22-T application.