Analog Devices Inc./Maxim Integrated MAX16055FAUB+T

Overview

MAX16055FAUB+T from Maxim Integrated is a precision hex voltage microprocessor (µP) supervisory IC that monitors six independent supply rails-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 -40°C to +125°C, features 140ms minimum reset timeout, 70µA internal RESET pullup to IN1, and supports 5%/10% tolerance selection via TOL pin. Used in automotive-grade server power sequencing and industrial multi-rail systems.

For engineers reviewing the MAX16055FAUB+T datasheet, MAX16055FAUB+T pinout, MAX16055FAUB+T application, or MAX16055FAUB+T equivalent, key selection criteria include factory-trimmed threshold accuracy (±1.5% for adjustable inputs), dual-voltage validity (RESET valid if IN1 ≥1V or IN2 ≥1V), manual reset input with 20kΩ internal pullup, immunity to short supply transients, and µMAX package compatibility with high-density PCB layouts.

Technical Context

The MAX16055FAUB+T integrates six independent voltage comparators with a shared precision bandgap reference and internal resistor-divider networks for fixed thresholds (3.3V/2.5V/1.5V on IN1/IN2/IN3 per Selector Guide), plus adjustable monitoring down to 0.5V on IN4–IN6. Its reset logic uses hysteresis (0.3% VTH) and propagation delay (20µs typical) to reject noise while ensuring deterministic assertion timing.

Power is derived solely from IN1 (1.0V–5.5V), which also serves as the monitored rail and internal pullup source for RESET. The device guarantees RESET validity as long as either IN1 or IN2 remains ≥1V, enabling robust operation during brown-out recovery across multiple supplies.

Key Specifications

Pinout & Package

MAX16055FAUB+T is housed in a 10-pin µMAX® package (3mm × 3mm, 0.5mm pitch), optimized for space-constrained automotive and industrial PCBs. Pin assignment follows standard top-view layout with GND at Pin 10 and RESET at Pin 9.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX16054FAUB+T, the MAX16055FAUB+T adds a sixth monitoring channel (IN6) without increasing footprint-critical for high-integration server and ADAS platforms. Against TPS3808G33DBVR, it delivers six-fold channel density, adjustable thresholds, and automotive temperature support in the same µMAX package, reducing total BOM count and layout complexity.

Availability

MAX16055FAUB+T is available at Aetrix Electronics and suitable for automotive ADAS modules, industrial PLCs, server motherboards, and medical imaging equipment requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX16055FAUB+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 demanding industrial, automotive, and communications applications.

The MAX16055FAUB+T belongs to Maxim's µP supervisory product line, designed specifically for compact, high-reliability multi-rail voltage monitoring in automotive-grade and industrial systems where space, accuracy, and temperature resilience are critical.

FAQ

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

The TOL pin on the MAX16055FAUB+T selects the threshold tolerance for all monitored inputs: connecting TOL to GND sets thresholds at -5% of nominal voltage, while connecting TOL to IN1 sets them at -10%. This allows precise margin testing of supply rails during design validation. The MAX16055FAUB+T does not operate correctly if TOL is left floating, and the selection directly affects hysteresis and trip-point accuracy across all six channels.

Can the MAX16055FAUB+T monitor voltages below 1.0V, and how is this achieved?

Yes, the MAX16055FAUB+T can monitor voltages as low as 0.5V using its adjustable inputs (IN4–IN6), each featuring a precise 0.5V internal reference with ±1.5% accuracy. To monitor a higher voltage (e.g., 1.2V), an external resistor divider scales the input so that the voltage at the pin equals 0.5V at the desired trip point. The MAX16055FAUB+T's internal clamp (~1.5V) limits input current, making high-value resistors (e.g., 100kΩ) practical for low-power designs.

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

The MAX16055FAUB+T guarantees RESET output validity as long as either IN1 ≥1V or IN2 ≥1V - a dual-voltage validity feature absent in most supervisors. This means RESET remains functional and correctly asserted/deasserted even if other monitored rails collapse, enabling safe recovery in multi-supply brown-out scenarios. The MAX16055FAUB+T leverages this to maintain system integrity without requiring auxiliary bias supplies.

Is an external pullup resistor required for the RESET output of the MAX16055FAUB+T?

No external pullup resistor is required when the MAX16055FAUB+T interfaces with logic operating from the same supply as IN1, thanks to its 70µA internal pullup to IN1. However, if RESET must drive a different logic rail (e.g., 1.8V or 5V), an external pullup resistor is necessary - and its value must be selected carefully to avoid excessive voltage rise at RESET when deasserted, as the internal 70µA current flows through it. The MAX16055FAUB+T datasheet provides guidance for calculating appropriate values.

What is the significance of the 140ms reset timeout period in the MAX16055FAUB+T?

The 140ms minimum reset timeout period in the MAX16055FAUB+T ensures that the RESET signal remains asserted long enough for all dependent processors, FPGAs, and memory subsystems to complete full power-on reset sequences - especially critical for complex SoCs with multi-stage initialization. This fixed delay begins only after all six monitored voltages have risen above their respective thresholds and hysteresis bands, preventing premature release during supply settling. The MAX16055FAUB+T guarantees this timing across -40°C to +125°C.