Analog Devices Inc./Maxim Integrated MAX16055FAUB+

Overview

The MAX16055FAUB+ from Maxim Integrated is a precision hex voltage microprocessor (µP) supervisory IC that monitors up to six system supply voltages-including 3.3V, 2.5V, and 1.5V fixed thresholds-and asserts a single active-low open-drain RESET output when any falls below its preset threshold. It operates from IN1 (1.0V–5.5V), features a 140ms minimum reset timeout, -40°C to +125°C automotive temperature range, and 10-pin µMAX (3mm × 3mm) package. Used in servers, industrial controllers, and telecom equipment for reliable power-on reset and brownout detection.

For engineers reviewing the MAX16055FAUB+ datasheet, MAX16055FAUB+ pinout, MAX16055FAUB+ application, or MAX16055FAUB+ equivalent, this page delivers verified electrical parameters, factory-trimmed threshold accuracy (±1.5% for adjustable inputs), tolerance-select logic (5%/10%), manual reset timing (200ns MR-to-RESET delay), and validated alternative parts for multi-rail monitoring designs.

Technical Context

The MAX16055FAUB+ implements six independent voltage comparators with internal precision reference and resistor-divider networks for fixed thresholds (3.3V/2.5V/1.5V on IN1/IN2/IN3 per Selector Guide), plus three adjustable inputs (IN4–IN6) referenced to a 0.5V internal threshold. Each comparator includes 0.3% VTH hysteresis to reject noise and short transients.

Power is derived solely from IN1, which also serves as a monitored rail; RESET remains valid as long as IN1 ≥1V or IN2 ≥1V. The open-drain RESET output integrates a 70µA internal pullup to IN1 and guarantees VOL ≤0.3V at ISINK = 2mA, enabling direct interface with 1.8V–5.5V logic without external pullups in many cases.

Key Specifications

Pinout & Package

Package: 10-pin µMAX (3mm × 3mm), RoHS-compliant, lead-free. Exposed pad not electrically connected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16054FAUB+, the MAX16055FAUB+ provides 2.5V and 1.5V fixed thresholds essential for legacy industrial interfaces and DDR memory rails, while the TPS3620-SEP trades configurability for radiation hardness-making it unsuitable for cost-sensitive terrestrial applications requiring six-rail coverage and adjustable monitoring.

Availability

The MAX16055FAUB+ is available at Aetrix Electronics and suitable for servers/workstations, industrial PLCs, telecom line cards, and automotive ADAS ECUs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX16055FAUB+ 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 demanding industrial, automotive, and communications applications, with emphasis on power management, sensing, and interface solutions.

The MAX16055FAUB+ belongs to Maxim's µP supervisory product line, engineered specifically for compact, multi-rail power monitoring in space-constrained systems where reliability across -40°C to +125°C is mandatory.

FAQ

What is the exact function of the TOL pin on the MAX16055FAUB+?

The TOL pin on the MAX16055FAUB+ selects the tolerance for all factory-set thresholds: connecting TOL to GND sets thresholds at -5% of nominal voltage (e.g., 3.15V for 3.3V), while connecting TOL to IN1 sets them at -10% (e.g., 2.97V for 3.3V). This pin must not be left floating, as undefined logic states may cause inconsistent reset behavior. The MAX16055FAUB+ uses this single control to configure all six monitored rails simultaneously.

Can the MAX16055FAUB+ monitor a 1.2V supply, and if so, how?

Yes, the MAX16055FAUB+ can monitor a 1.2V supply using an adjustable input (IN4–IN6) configured with an external resistor divider. Since the internal reference is 0.5V, a 1.2V rail requires R1/R2 ≈ 1.4:1 (e.g., R1 = 140kΩ, R2 = 100kΩ). The MAX16055FAUB+ datasheet confirms 1.2V is supported in the Selector Guide for variants like MAX16055A, but MAX16055FAUB+ itself uses IN1=3.3V, IN2=2.5V, IN3=1.5V, and adjustable IN4–IN6 - so 1.2V monitoring is fully supported via divider on IN4, IN5, or IN6.

Does the MAX16055FAUB+ require external pullup resistors on its RESET output?

No, the MAX16055FAUB+ does not require an external pullup resistor on RESET in most cases because it integrates a 70µA internal pullup to IN1. This is sufficient to drive standard CMOS inputs when RESET interfaces with logic powered from the same IN1 rail (e.g., 3.3V microcontroller). An external pullup is needed only when interfacing with a different voltage domain (e.g., 1.8V I/O), and even then, the MAX16055FAUB+'s internal clamp prevents reverse current flow.

What is the minimum pulse width required on the MR pin of the MAX16055FAUB+?

The MR pin of the MAX16055FAUB+ requires a minimum pulse width of 1µs to reliably assert RESET. This specification is guaranteed across the full -40°C to +125°C temperature range and ensures compatibility with fast digital outputs or debounced mechanical switches. The MAX16055FAUB+ also includes 100ns glitch rejection, meaning sub-100ns noise spikes on MR will not trigger spurious resets - a key feature for noisy industrial environments.

How does the MAX16055FAUB+ maintain RESET validity during partial power loss?

The MAX16055FAUB+ maintains RESET validity as long as either IN1 ≥1V or IN2 ≥1V, per the Absolute Maximum Ratings and Electrical Characteristics tables. This dual-rail validity window allows continued reset assertion during brownout conditions where only one supply remains marginally active - critical for orderly shutdown in systems with redundant power paths. The MAX16055FAUB+ leverages this feature to avoid premature deassertion when IN3–IN6 collapse but IN1 or IN2 sustains above 1V.