Analog Devices Inc./Maxim Integrated MAX16055AAUB+

Overview

The MAX16055AAUB+ from Maxim Integrated is a precision hex voltage microprocessor (µP) supervisory IC that monitors up to six system supply rails-including 3.3V, 2.5V, 1.5V, 1.8V, 1.2V, and 0.9V-and asserts a single active-low open-drain RESET output when any falls below its factory-trimmed threshold. It operates from IN1 (1.0V–5.5V), features a fixed 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 MAX16055AAUB+ datasheet, MAX16055AAUB+ pinout, MAX16055AAUB+ application, or MAX16055AAUB+ equivalent, this page delivers verified specifications, terminal roles, real-world use cases, and validated alternative parts-enabling rapid validation of supply monitoring architecture without external component proliferation.

Technical Context

The MAX16055AAUB+ integrates six independent voltage comparators with a shared internal 0.5V reference and precision resistor-divider networks to set factory-fixed thresholds. Each monitored input (IN1–IN6) connects directly to its comparator, with built-in 0.3% hysteresis and immunity to transients ≤100ns.

Its RESET output is open-drain with a 70µA internal pullup to IN1, remains valid as long as IN1 ≥1V or IN2 ≥1V, and includes a manual reset (MR) input with 20kΩ internal pullup and 1µs minimum pulse width support. Tolerance selection (5%/10%) is controlled via the TOL pin tied to GND or IN1.

Key Specifications

Pinout & Package

Package: 10-pin µMAX® (3mm × 3mm), RoHS-compliant, lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and ADM1266ACPZ, the MAX16055AAUB+ delivers optimal balance of integration, zero-config operation, and automotive-grade reliability for fixed-threshold hex supervision-reducing component count by 83% versus discrete solutions while avoiding software dependencies of programmable alternatives.

Availability

MAX16055AAUB+ is available at Aetrix Electronics and suitable for servers/workstations, industrial PLCs, and automotive ADAS ECUs requiring stable component supply, long-lifecycle support, and AEC-Q100-aligned qualification.

Supply support for MAX16055AAUB+ 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 high-performance analog, mixed-signal, and power-management ICs for demanding industrial, automotive, and communications applications.

The MAX16055AAUB+ belongs to Maxim's µP supervisory product line, engineered specifically for compact, reliable multi-rail power monitoring in space-constrained and thermally aggressive environments.

FAQ

What is the function of the TOL pin on the MAX16055AAUB+?

The TOL pin on the MAX16055AAUB+ selects the threshold tolerance for all monitored inputs: connecting TOL to GND sets thresholds at −5% of nominal voltage, while connecting it to IN1 sets them at −10%. This allows design flexibility for varying supply tolerances without changing the part number. The MAX16055AAUB+ requires TOL to be actively driven-leaving it floating may cause undefined reset behavior. Internal logic ensures consistent tolerance application across all six inputs simultaneously.

Does the MAX16055AAUB+ require external pullup resistors on the RESET output?

The MAX16055AAUB+ includes a 70µA internal pullup current sourced from IN1 to the open-drain RESET pin, eliminating the need for an external pullup in most 3.3V or 2.5V logic interfaces. However, if interfacing with a logic rail lower than IN1 (e.g., RESET pulled to 1.8V while IN1 = 3.3V), an external pullup resistor is required to prevent elevated RESET voltage during deassertion. The MAX16055AAUB+ datasheet specifies maximum allowable pullup resistance based on sink current and logic-high threshold.

How does the MAX16055AAUB+ ensure RESET validity during low-voltage conditions?

The MAX16055AAUB+ guarantees RESET output validity as long as either IN1 ≥1V or IN2 ≥1V, per its absolute rating and functional specification. Below 1V on both IN1 and IN2, RESET becomes indeterminate-even if other inputs (IN3–IN6) remain above threshold. This dual-input validity window ensures robust operation during asymmetric power-down sequences. The MAX16055AAUB+ draws <70µA quiescent current at 1V, enabling extended hold-up time with small bypass capacitors.

Can unused inputs on the MAX16055AAUB+ be left floating?

No-unused inputs on the MAX16055AAUB+ must not be left floating. For factory-trimmed inputs (e.g., IN3–IN6 in the AAUB+ variant), connect to a supply voltage exceeding their threshold (e.g., tie IN3 to 3.3V if monitoring 1.5V). For adjustable inputs, connect via a 100kΩ resistor to IN1 to limit bias current. Floating inputs risk false resets due to leakage-induced threshold crossing. The MAX16055AAUB+ datasheet explicitly prohibits unconnected monitor pins to maintain specified accuracy and noise immunity.

What is the reset timeout behavior of the MAX16055AAUB+ after all supplies recover?

After all monitored inputs (IN1–IN6) rise above their respective thresholds, the MAX16055AAUB+ holds RESET low for a minimum of 140ms before releasing it high-this fixed timeout is internally generated and requires no external components. The actual timeout varies from 140ms to 280ms over temperature and supply, but the minimum guarantee ensures sufficient delay for processor PLL lock and memory initialization. The MAX16055AAUB+ does not restart the timeout if a supply dips and recovers within the period; it only triggers anew upon full recovery from a full undervoltage event.