Analog Devices Inc./Maxim Integrated MAX6401BS22+T

Overview

MAX6401BS22+T from Maxim Integrated is an ultra-low-power microprocessor supervisory circuit with active-high push-pull reset output, factory-trimmed 2.20V reset threshold (±2.5% over –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 MAX6401BS22+T datasheet, MAX6401BS22+T pinout, MAX6401BS22+T application, or MAX6401BS22+T equivalent, key selection criteria include its active-high reset logic, 2.20V trip point, UCSP-4 package compatibility, guaranteed reset validity to 1.0V, and immunity to sub-200ns VCC transients - critical for reliable boot sequencing in low-voltage embedded designs.

Technical Context

The MAX6401BS22+T integrates a precision bandgap reference comparator and internal timer to assert RESET high when VCC falls below 2.20V, holding it high for ≥100ms after VCC recovers. Its push-pull output drives directly without external pullup, unlike open-drain variants.

It features a manually triggered reset via MR pin with internal 50kΩ pullup, 1µs minimum pulse width, and 200ns MR-to-reset delay. Reset assertion remains valid across full –40°C to +85°C temperature range with ±2.5% threshold accuracy and 40ppm/°C tempco.

Key Specifications

Pinout & Package

MAX6401BS22+T is housed in a 4-bump, 2mm × 2mm UCSP (Ultra Compact Silicon Package) with bottom-side solder bumps - footprint-compatible with SC70 but 70% smaller. This chip-scale package requires optimized PCB layout per Maxim's UCSP reliability guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6400BS22+T, the MAX6401BS22+T provides active-high reset logic essential for modern µPs with high-active reset pins, while TPS3808G12DBVR offers higher voltage margin and longer timeout at the cost of 3.2× higher quiescent current and non-chip-scale packaging.

Availability

MAX6401BS22+T is available at Aetrix Electronics and suitable for portable electronics, battery-powered data loggers, and wearable medical devices requiring stable component supply with long-lifecycle support and traceable sourcing.

Supply support for MAX6401BS22+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 management, 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 space- and energy-constrained portable systems, featuring chip-scale packaging and nanoscale quiescent current.

FAQ

What is the exact reset threshold voltage of the MAX6401BS22+T and how tightly is it specified?

The MAX6401BS22+T has a nominal reset threshold of 2.20V, factory-trimmed with ±1.5% accuracy at +25°C and ±2.5% over the full –40°C to +85°C operating range. This specification is confirmed in the Electrical Characteristics table and Selector Guide of the official datasheet, ensuring predictable brownout detection across temperature extremes without external calibration.

Does the MAX6401BS22+T require an external pullup resistor on its RESET pin?

No, the MAX6401BS22+T features an active-high push-pull RESET output and does not require an external pullup resistor. Its output stage actively drives high during reset assertion and low otherwise, enabling direct connection to microcontrollers with high-active reset inputs - a key differentiator from open-drain or active-low variants like MAX6402BS22+T.

What is the minimum VCC voltage at which the MAX6401BS22+T guarantees correct RESET output logic state?

The MAX6401BS22+T guarantees correct RESET output logic state down to VCC = 1.0V, as explicitly stated in the General Description and Absolute Maximum Ratings sections. This ensures reliable reset assertion even during deep battery discharge or severe brownout conditions, preventing undefined microprocessor behavior.

How does the manual reset (MR) function behave on the MAX6401BS22+T?

The MR input on the MAX6401BS22+T is active-low with an internal 50kΩ pullup to VCC. Pulling MR low asserts RESET high for the duration of the low pulse plus the full 100ms reset timeout period. The device accepts TTL/CMOS logic levels and requires no external components - a momentary switch from MR to GND suffices for field reset capability.

Is the MAX6401BS22+T compatible with standard reflow soldering processes?

Yes, the MAX6401BS22+T in UCSP-4 package is qualified for standard lead-free reflow profiles, with a maximum bump reflow temperature of +235°C. However, Maxim emphasizes that UCSP reliability depends critically on user-specific PCB material, assembly method, and thermal profile - full qualification details are provided in the UCSP Reliability section of the datasheet.