Analog Devices Inc./Maxim Integrated MAX6401BS26

Overview

MAX6401BS26 from Maxim Integrated is an ultra-low-power microprocessor supervisory circuit with active-high push-pull reset output, factory-trimmed 2.63V ±2.5% threshold (–40°C to +85°C), 100ms minimum reset timeout, and 500nA typical supply current at 3.0V. It monitors VCC down to 1.0V and supports manual reset input for brownout and power-up supervision in portable battery-powered systems.

For engineers reviewing the MAX6401BS26 datasheet, MAX6401BS26 pinout, MAX6401BS26 application, or MAX6401BS26 equivalent, this device serves as a precision voltage monitor with guaranteed logic state integrity below 1V, immunity to fast VCC transients, and direct integration into space-constrained designs using its 2×2 mm UCSP package.

Technical Context

The MAX6401BS26 implements a precision bandgap reference comparator with factory-trimmed trip point at 2.63V, delivering ±2.5% accuracy over –40°C to +85°C and 40ppm/°C tempco. Its internal timer enforces a minimum 100ms reset timeout after VCC rises above threshold, and it guarantees valid reset assertion down to VCC = 1.0V.

It features an active-high push-pull RESET output capable of sourcing ≥500µA at 0.8×VCC while asserted high, and sinking ≤0.4V at 1.2mA when not asserted. The MR input includes a 50kΩ internal pullup, accepts TTL/CMOS levels, and rejects glitches <100ns.

Key Specifications

Pinout & Package

MAX6401BS26 is housed in a 4-bump, 2×2 mm chip-scale package (UCSP-4) with solder bumps replacing leads. This ultra-compact footprint reduces board area by 70% versus SC70 and eliminates leadframe parasitics for improved high-frequency noise immunity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6401BS27-T, the MAX6401BS26 offers a 70mV lower trip point for earlier brownout response; compared with TPS3808G12DBVR, it delivers 3.2× lower supply current and eliminates external pullup, making it superior for space- and energy-constrained applications.

Availability

MAX6401BS26 is available at Aetrix Electronics and suitable for portable medical sensors, smart wearables, and industrial handheld terminals requiring stable component supply, long-term lifecycle support, and consistent UCSP-4 packaging.

Supply support for MAX6401BS26 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 emphasis on high-reliability, low-power solutions.

The MAX6400–MAX6405 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical portable equipment, integrating precision voltage monitoring, manual reset, and reset timing in minimal footprint.

FAQ

What is the exact reset threshold voltage of MAX6401BS26 and how stable is it over temperature?

The MAX6401BS26 has a nominal reset threshold of 2.63V, with ±2.5% accuracy guaranteed over the full –40°C to +85°C operating range. Its temperature coefficient is 40ppm/°C, meaning drift is limited to ±0.105V across the entire temperature span. This stability is achieved via factory trimming of an internal bandgap reference comparator, eliminating need for external calibration.

Does MAX6401BS26 require an external pullup resistor on its RESET pin?

No, MAX6401BS26 does not require an external pullup resistor because it features an active-high push-pull output. Unlike open-drain supervisors, the MAX6401BS26 internally sources current when asserting RESET high and sinks current when inactive, enabling direct connection to microcontroller reset inputs without additional components.

Can MAX6401BS26 operate reliably below 1.2V supply voltage?

Yes, MAX6401BS26 is guaranteed to maintain correct reset logic state down to VCC = 1.0V, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables. While the recommended operating range starts at 1.2V, the device continues to assert valid active-high RESET output even at 1.0V, supporting graceful shutdown during deep battery depletion.

What is the function of the MR pin on MAX6401BS26 and how should it be used?

The MR (Manual Reset) pin on MAX6401BS26 is an active-low input with a 50kΩ internal pullup to VCC. Pulling MR to GND for ≥1µs initiates a reset pulse lasting ≥100ms. It can be driven by a momentary switch, GPIO, or open-drain logic. Leaving MR unconnected defaults to high, disabling manual reset - no external pullup is required.

How does MAX6401BS26 handle short voltage transients on the VCC line?

MAX6401BS26 rejects negative-going VCC transients shorter than 100ns and up to 100mV amplitude, as specified in its MR glitch rejection and VCC transient immunity characteristics. Its internal comparator includes filtering that prevents false resets during switching regulator noise or ESD-induced dips, ensuring robust operation in electrically noisy environments.