Analog Devices Inc./Maxim Integrated MAX6855UK41D4+T

Overview

The MAX6855UK41D4+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, providing voltage monitoring, manual reset input (MR), and fixed 1200ms minimum reset timeout. It asserts an active-high push-pull RESET output when VCC drops below its factory-trimmed 4.100V threshold, MR is pulled low, or during power-up/brownout - ensuring reliable µP initialization in battery-powered medical and portable electronics.

For engineers reviewing the MAX6855UK41D4+T datasheet, MAX6855UK41D4+T pinout, MAX6855UK41D4+T application, or MAX6855UK41D4+T equivalent, key selection criteria include its 4.100V reset threshold, 1200ms timeout, active-high push-pull output, ultra-low 170nA typical supply current, and guaranteed reset validity down to VCC = +1.1V.

Technical Context

This device implements a precision bandgap-based voltage monitor with ±2.5% threshold accuracy over temperature, coupled with a digital timeout counter that holds RESET asserted for ≥1200ms after VCC rises above VTH and MR deasserts. Its internal 10kΩ MR pullup enables direct CMOS-level manual reset control without external components.

The active-high push-pull RESET output is referenced to VCC and delivers VOH ≥ 0.8×VCC at ISOURCE = 500µA (VCC ≥ 2.38V), while VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V). It guarantees functional reset assertion down to VCC = +1.1V, making it suitable for deep brownout detection in low-voltage systems.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (lead-free, +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 TPS3837K33DBVR, MAX6855UK41D4+T provides higher reset threshold and longer timeout for 4V-class systems, while MAX6369KA29D3+T offers identical timing and drive strength at a lower voltage point - enabling precise rail-specific supervision without layout changes.

Availability

MAX6855UK41D4+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, smart wearables, and industrial handheld terminals requiring stable component supply across extended production lifecycles.

Supply support for MAX6855UK41D4+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, sensing, and connectivity in demanding industrial, medical, and portable applications.

The MAX6854–MAX6869 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical devices, emphasizing nanopower operation, guaranteed low-VCC reset validity, and minimal external component count.

FAQ

What is the exact reset threshold voltage of the MAX6855UK41D4+T?

The MAX6855UK41D4+T has a factory-trimmed reset threshold of 4.100V, with ±2.5% tolerance over temperature (−40°C to +85°C). This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix "41" corresponds to VTH = 4.100V (min 3.998V, typ 4.100V, max 4.203V). The MAX6855UK41D4+T uses this precise threshold to supervise 3.3V or 4.2V battery-backed rails.

Does the MAX6855UK41D4+T include a watchdog timer function?

No, the MAX6855UK41D4+T does not include a watchdog timer. Per the Selector Guide and Pin Configurations, MAX6855 variants lack WDI (Watchdog Input) functionality - only MAX6864–MAX6869 parts integrate watchdog capability. The MAX6855UK41D4+T provides voltage monitoring, manual reset (MR), and fixed 1200ms reset timeout, but no watchdog timer circuitry.

What is the reset output configuration of the MAX6855UK41D4+T?

The MAX6855UK41D4+T features an active-high push-pull RESET output (Pin 1), as specified in the MAX6854/MAX6855/MAX6856 Pin Description table. Unlike open-drain versions, it drives high directly to VCC and low to GND without requiring an external pullup resistor - simplifying interface to µP reset inputs expecting active-high assertion.

Can the MAX6855UK41D4+T operate reliably below 1.8V?

Yes, the MAX6855UK41D4+T guarantees functional reset assertion down to VCC = +1.1V, as stated in the Electrical Characteristics table and Detailed Description section. Its supply voltage range is 1.2V to 5.5V, and it maintains valid RESET output behavior even as VCC falls through the 1.2V–1.8V range - critical for detecting deep brownout in Li-ion or multi-cell alkaline systems.

Is the MAX6855UK41D4+T pin-compatible with other supervisory ICs?

The MAX6855UK41D4+T is pin-compatible with the TPS3836/TPS3837/TPS3838 family per the Features section, sharing the same 5-pin SOT23-5 footprint and GND–MR–VCC–RESET–GND pinout order. However, output polarity differs: MAX6855UK41D4+T uses active-high push-pull, while TPS3837 is open-drain active-low - requiring schematic review before substitution.