Analog Devices Inc./Maxim Integrated MAX6855UK32D4+T

Overview

The MAX6855UK32D4+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 3.2V reset threshold (±2.5%), and 1200ms 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-powered medical and portable electronics.

For engineers reviewing the MAX6855UK32D4+T datasheet, MAX6855UK32D4+T pinout, MAX6855UK32D4+T application, or MAX6855UK32D4+T equivalent, this page delivers verified functional identity, confirmed pin roles, exact reset timing behavior, true low-power operation down to VCC = 1.1V, and validated alternative options for voltage-monitoring supervisory use cases.

Technical Context

This device implements a precision bandgap-based voltage monitor with hysteresis (0.5% of VTH), a digital reset timeout timer with guaranteed 1200ms minimum assertion, and an internally pulled-up MR input (10kΩ) that triggers reset on logic-low assertion. The active-high push-pull RESET output is referenced to VCC and sinks ≤0.3V at 1.2mA load when asserted.

No watchdog timer or CT select input is present - the MAX6855UK32D4+T belongs to the MAX6854/MAX6855/MAX6856 family subset with manual reset only and fixed reset timeout (D4 = 1200ms). Its reset validity extends to VCC = 1.1V, and it is immune to VCC transients ≤40µs at 100mV overdrive.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Pin 1 is RESET (active-high push-pull), Pin 2 and Pin 4 are GND, Pin 3 is MR (active-low manual reset), Pin 5 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3837K33DBVR and MAX6315US32D3+T, the MAX6855UK32D4+T uniquely combines ultra-low 170nA current, 1200ms timeout, and active-high push-pull output - making it optimal for long-life, high-reliability medical devices where reset timing margin and power efficiency are non-negotiable.

Availability

MAX6855UK32D4+T is available at Aetrix Electronics and suitable for glucose monitoring systems, portable patient monitors, industrial handheld scanners, and smart wearable health trackers requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6855UK32D4+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 MAX6855UK32D4+T belongs to the MAX6854–MAX6869 nanopower supervisory family, engineered specifically for ultra-low-power, single-supply voltage monitoring in battery-critical portable medical and consumer electronics.

FAQ

What is the exact reset threshold voltage of the MAX6855UK32D4+T?

The MAX6855UK32D4+T has a factory-trimmed reset threshold of 3.200V with ±2.5% tolerance over temperature (-40°C to +85°C), corresponding to the "32" suffix per Maxim's Threshold Suffix Guide. This value is measured at VCC falling and guarantees reliable detection of brownout on nominal 3.3V rails. The MAX6855UK32D4+T does not require external calibration or resistor dividers to achieve this accuracy.

Does the MAX6855UK32D4+T include a watchdog timer function?

No, the MAX6855UK32D4+T does not include a watchdog timer. It belongs to the MAX6854/MAX6855/MAX6856 subgroup, which provides only voltage monitoring and manual reset functionality. Watchdog capability is exclusive to MAX6864–MAX6869 variants (e.g., MAX6864UK32D4S+T), identifiable by the "S" or "L" suffix in the ordering code. The MAX6855UK32D4+T pinout and functional diagram confirm absence of WDI input.

What is the RESET output configuration of the MAX6855UK32D4+T?

The MAX6855UK32D4+T features an active-high push-pull RESET output (Pin 1), meaning it drives high during reset assertion and low when deasserted. Unlike open-drain versions, it requires no external pullup resistor and sources up to 500µA while maintaining VOH ≥ 0.8×VCC. This matches the MAX6855 designation in the Selector Guide and is confirmed in the Pin Description table for MAX6855.

Can the MAX6855UK32D4+T operate with supply voltages below 1.8V?

Yes, the MAX6855UK32D4+T operates from VCC = 1.2V to 5.5V and guarantees valid reset assertion down to VCC = 1.1V - critical for detecting deep brownout in lithium primary cells or aging batteries. At 1.2V, supply current is 190nA (typ), and RESET output remains functional with VOL ≤ 0.3V at 50µA sink. This behavior is explicitly specified in the Electrical Characteristics table.

Is the MAX6855UK32D4+T pin-compatible with other supervisory ICs?

The MAX6855UK32D4+T uses a standard 5-pin SOT23-5 package with GND on Pins 2 and 4, MR on Pin 3, RESET on Pin 1, and VCC on Pin 5 - matching the footprint of TPS3836/TPS3837/TPS3838 series. However, RESET polarity (active-high vs. active-low) and output type (push-pull vs. open-drain) differ; direct replacement requires schematic review. The MAX6855UK32D4+T is not pin-compatible with MAX6854 or MAX6856 due to differing RESET configurations.