Analog Devices Inc./Maxim Integrated MAX6855UK16D2+T

Overview

The MAX6855UK16D2+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, providing voltage monitoring, manual reset input (MR), and active-low push-pull reset output. It asserts reset when VCC drops below 1.575V (factory-trimmed threshold), MR is pulled low, or watchdog timeout occurs - with guaranteed reset validity down to VCC = +1.1V and ultra-low 170nA typical supply current. It serves critical power-up/brownout protection in battery-powered medical and portable electronics.

For engineers reviewing the MAX6855UK16D2+T datasheet, MAX6855UK16D2+T pinout, MAX6855UK16D2+T application, or MAX6855UK16D2+T equivalent, key selection criteria include its 1.575V reset threshold, 40ms minimum reset timeout (D2), push-pull active-high RESET output, -40°C to +85°C operation, and immunity to short VCC transients - all validated for low-power µP supervision where supply current and voltage margin are design-critical.

Technical Context

The MAX6855UK16D2+T implements a precision bandgap-based voltage monitor with ±2.5% threshold accuracy over temperature, coupled with a digital reset timeout timer that holds RESET asserted for ≥40ms after VCC rises above VTH and MR deasserts. Its MR input features internal 10kΩ pullup, 1µs minimum pulse width support, and 200ns glitch rejection - enabling robust manual reset initiation without external components.

This device belongs to the MAX6854–MAX6869 family of nanopower supervisors and uses BiCMOS process technology (2848 transistors) to achieve 170nA typical ICC at 2.5V while maintaining guaranteed reset assertion down to VCC = 1.1V - a key differentiator for deep-battery-discharge applications where conventional supervisors fail.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, footprint compatible with industry-standard 5-pin SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3837K33DBVR and MAX6315US29D3+, the MAX6855UK16D2+T delivers 7× lower supply current, factory-trimmed 1.575V threshold for Li-ion compatibility, and integrated MR - making it uniquely suitable for next-generation ultra-low-power medical and portable devices where battery life and voltage margin are non-negotiable.

Availability

MAX6855UK16D2+T is available at Aetrix Electronics and suitable for glucose monitors, patient vital sign recorders, smart wearables, and industrial handheld scanners requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6855UK16D2+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 industrial, medical, and communications applications.

The MAX6854–MAX6869 family was designed specifically for nanopower microprocessor supervision in battery-constrained systems - prioritizing ultra-low ICC, wide VCC range, and guaranteed reset functionality at near-dead-battery voltages.

FAQ

What is the exact reset threshold voltage of the MAX6855UK16D2+T?

The MAX6855UK16D2+T has a factory-trimmed reset threshold voltage of 1.575V, with ±2.5% tolerance over the full -40°C to +85°C operating temperature range. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix '16' corresponds to 1.575V nominal. The device guarantees valid reset assertion down to VCC = 1.1V, making it suitable for lithium coin-cell and deeply discharged Li-ion applications where other supervisors fail.

Does the MAX6855UK16D2+T include a watchdog timer function?

No, the MAX6855UK16D2+T does not include a watchdog timer. Per the Selector Guide and Pin Description sections, only MAX6864–MAX6869 variants feature WDI input and watchdog timeout functionality. The MAX6855UK16D2+T is a manual-reset-only supervisor with MR input and push-pull active-high RESET output - confirmed by its absence from the WDI column in the Selector Guide and lack of WDI pin in its pin configuration diagram.

What does the 'D2' in MAX6855UK16D2+T indicate?

The 'D2' suffix in MAX6855UK16D2+T specifies the reset timeout period: D2 corresponds to a minimum 40ms reset timeout (typical 60ms, maximum 80ms), as defined in Table 4 (Reset Timeout Periods) of the datasheet. This timeout begins after VCC rises above the 1.575V threshold and MR is deasserted, ensuring sufficient hold time for microprocessor core initialization and peripheral stabilization before firmware execution resumes.

Is the MAX6855UK16D2+T pin-compatible with other devices in the MAX68xx family?

The MAX6855UK16D2+T shares the same 5-pin SOT23-5 package and pinout (RESET, GND, MR, GND, VCC) with MAX6854, MAX6856, MAX6861–MAX6863, and MAX6864–MAX6869 - but functional compatibility depends on reset polarity and feature set. Unlike MAX6854 (active-low push-pull) or MAX6856 (open-drain), the MAX6855UK16D2+T provides active-high push-pull RESET, requiring circuit-level verification before substitution.

What is the supply current specification for MAX6855UK16D2+T at 1.8V and 25°C?

At VCC = 1.8V and TA = +25°C, the MAX6855UK16D2+T draws 170nA typical supply current (ICC), as specified in the Electrical Characteristics table under "Supply Current" with condition VCC = 1.8V. This ultra-low value is consistent across the MAX6854–MAX6869 family and is measured with reset output deasserted and no load - enabling multi-year operation from primary batteries in always-on medical sensors.