Analog Devices Inc./Maxim Integrated MAX6400BS22+

Overview

MAX6400BS22+ 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, 500nA typical supply current at 3.0V, factory-trimmed ±2.5% threshold accuracy over –40°C to +85°C, and guaranteed reset validity down to VCC = 1.0V. It is used in battery-powered portable devices requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6400BS22+ datasheet, MAX6400BS22+ pinout, MAX6400BS22+ application, or MAX6400BS22+ equivalent, this page provides verified technical context, pin-level design meaning, real-world use scenarios, and validated alternative options for portable system supervision with sub-2.5V threshold requirements.

Technical Context

The MAX6400BS22+ integrates a precision bandgap reference comparator with internal hysteresis (6.3mV) and a 100ms minimum reset timeout timer. Its reset assertion logic is synchronized to VCC crossing the 2.20V threshold, with immunity to transients ≤20µs at 100mV overdrive - confirmed by Typical Operating Characteristics graphs.

It operates across VCC = 1.2V to 5.5V (–40°C to +85°C), draws only 0.5µA typical supply current at 3.0V, and guarantees correct RESET output state down to VCC = 1.0V. The manual reset input (MR) includes a 50kΩ internal pullup and supports TTL/CMOS-compatible triggering with <1µs minimum pulse width.

Key Specifications

Pinout & Package

MAX6400BS22+ is housed in a 4-bump UCSP (Ultra Compact Silicon Package), measuring 2mm × 2mm with 0.5mm bump pitch. This chip-scale package reduces board area by 70% versus SC70 and is 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 STM6315RWX6F, the MAX6400BS22+ delivers 3.6× lower supply current and 70% smaller footprint - making it uniquely suited for space- and energy-constrained portable designs where 2.20V threshold precision and MR support are mandatory.

Availability

MAX6400BS22+ is available at Aetrix Electronics and suitable for portable/battery-powered equipment, cell phones, and MP3 players requiring stable component supply, long-term lifecycle support, and guaranteed factory-trimmed voltage thresholds.

Supply support for MAX6400BS22+ 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, 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 portable electronics - prioritizing nanoscale current consumption, chip-scale packaging, and factory-trimmed accuracy to eliminate external calibration.

FAQ

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

The MAX6400BS22+ has a nominal reset threshold of 2.20V, with ±2.5% tolerance over the full –40°C to +85°C operating temperature range. At +25°C, the threshold is specified as 2.167V (min) to 2.233V (max). This precision is achieved via factory laser trimming of the internal bandgap reference comparator, eliminating need for external adjustment. The MAX6400BS22+ datasheet confirms these values in Table 1 and Electrical Characteristics sections.

Does MAX6400BS22+ require external components to operate?

No, the MAX6400BS22+ requires zero external components for basic supervision functionality. Its factory-trimmed 2.20V threshold, integrated 100ms reset timeout timer, active-low push-pull RESET output, and internal 50kΩ MR pullup resistor enable standalone operation. Only optional noise filtering (e.g., 0.1µF capacitor on MR) is recommended in electrically noisy environments - not required for standard use. This integration is explicitly stated in the General Description and Features sections of the MAX6400BS22+ datasheet.

What is the minimum VCC voltage at which MAX6400BS22+ guarantees correct RESET output state?

The MAX6400BS22+ guarantees correct RESET output logic state - specifically, RESET remains asserted low when VCC is below 2.20V - down to VCC = 1.0V. This is confirmed in the General Description ("All parts are guaranteed to be in the correct output logic state for VCC down to 1V") and Electrical Characteristics table (VCC = 1.2V min for full spec, but RESET validity extended to 1.0V). This feature ensures reliable reset hold during deep battery discharge in portable systems.

How does the manual reset (MR) input function on MAX6400BS22+?

The MR input on MAX6400BS22+ is active-low with an internal 50kΩ pullup resistor to VCC. Pulling MR low asserts RESET immediately, and RESET remains low for the full 100ms reset timeout period after MR returns high. MR accepts TTL/CMOS logic levels and can be driven by a momentary switch to GND - no external debouncing or pullup is needed. The MAX6400BS22+ datasheet specifies MR minimum pulse width as 1µs and glitch rejection as 100ns, confirming robust noise immunity.

What package type and dimensions does MAX6400BS22+ use?

The MAX6400BS22+ uses a 4-bump UCSP (Ultra Compact Silicon Package) with 2mm × 2mm body size and 0.5mm bump pitch. This chip-scale package is documented in the Package Information section as "4L, UCSP 2x2.EPS" and noted to be 70% smaller than SC70. The pin configuration (GND/A1, RESET/B1, MR/B2, VCC/A2) is confirmed in the Pin Description table, and reliability notes emphasize board-level assembly considerations specific to this CSP form factor.