Analog Devices Inc./Maxim Integrated MAX6855UK20D1+T

Overview

The MAX6855UK20D1+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 2.0V reset threshold (±2.5%), and a 10ms minimum reset timeout period. It provides active-high push-pull RESET output, manual reset input (MR), and operates across -40°C to +85°C - designed for reliable power-on reset and brownout protection in battery-critical systems like glucose monitors and portable medical devices.

For engineers reviewing the MAX6855UK20D1+T datasheet, MAX6855UK20D1+T pinout, MAX6855UK20D1+T application, or MAX6855UK20D1+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing behavior, and real-world selection guidance - all grounded in Maxim's official electrical characteristics and pin configuration data.

Technical Context

The MAX6855UK20D1+T implements a precision voltage monitor with guaranteed reset validity down to VCC = +1.1V and immunity to short VCC transients (e.g., ≤40µs at 100mV overdrive). Its internal 10kΩ MR pullup enables direct CMOS-level manual reset assertion without external components.

Unlike watchdog-equipped variants (e.g., MAX6864–MAX6869), the MAX6855UK20D1+T omits WDI and CT pins - confirming it is a dedicated voltage-monitoring + MR supervisory device with fixed 10ms timeout and active-high push-pull RESET output only.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free (indicated by "+T" suffix), footprint-compatible with industry-standard 5-lead SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K20DBVR and STM6315SWX6F, the MAX6855UK20D1+T uniquely combines ultra-low 170nA ICC, active-high push-pull RESET, and 10ms timeout - making it optimal for space-constrained, battery-limited medical wearables where power efficiency and pin-compatible simplicity are primary design drivers.

Availability

MAX6855UK20D1+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered PDAs, wireless patient monitors, and low-power IoT edge nodes requiring stable component supply and long-term lifecycle support.

Supply support for MAX6855UK20D1+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) designs precision analog and mixed-signal ICs for power management, sensing, and interface applications - with emphasis on ultra-low-power, high-reliability solutions.

The MAX6854–MAX6869 family was engineered specifically for nanopower supervisory functions in battery-critical systems, delivering factory-trimmed thresholds, minimal ICC, and robust transient immunity without external components.

FAQ

What is the exact reset threshold voltage of the MAX6855UK20D1+T?

The MAX6855UK20D1+T has a factory-trimmed reset threshold voltage of 2.0V with ±2.5% tolerance over -40°C to +85°C, as defined by the "20" suffix in its part number per Maxim's Threshold Suffix Guide (Table 2). This value is measured at VCC falling and guarantees deterministic reset assertion during brownout events on 2.0V rails.

Does the MAX6855UK20D1+T include a watchdog timer function?

No, the MAX6855UK20D1+T does not include a watchdog timer. Per Maxim's Selector Guide and Pin Configurations, only MAX6864–MAX6869 variants feature WDI pins; the MAX6855UK20D1+T is a voltage-monitoring + manual reset device with no watchdog circuitry, confirmed by absence of WDI pin and related timing specs in its datasheet sections.

What is the RESET output type and drive capability of the MAX6855UK20D1+T?

The MAX6855UK20D1+T features an active-high push-pull RESET output. When deasserted, it sources ≥0.8×VCC at 200µA (VCC ≥1.71V); when asserted, it sinks ≤0.3V at 500µA (VCC ≥2.38V). This eliminates need for external pullup resistors and ensures direct compatibility with µP reset inputs requiring high-true logic levels.

How does the manual reset (MR) pin operate on the MAX6855UK20D1+T?

The MR pin on the MAX6855UK20D1+T is an active-low input with internal 10kΩ pullup to VCC. Driving MR low asserts RESET immediately, and RESET remains asserted for the full 10ms timeout after MR returns high. Glitch rejection is 200ns, and minimum MR pulse width is 1µs - enabling reliable reset initiation via momentary switches or digital logic without external debouncing.

Is the MAX6855UK20D1+T pin-compatible with other devices in the MAX68xx family?

The MAX6855UK20D1+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 differs in RESET polarity and feature set. While physically pin-compatible, functional substitution requires verification of RESET polarity (active-high vs. active-low) and presence/absence of WDI or CT pins per application requirements.