Analog Devices Inc./Maxim Integrated MAX6855UK26D4+T

Overview

The MAX6855UK26D4+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, factory-trimmed 2.625V reset threshold (suffix '26'), and 1200ms minimum reset timeout (suffix 'D4'). It provides active-high push-pull RESET output, manual reset input (MR), and operates across –40°C to +85°C for battery-powered medical and portable electronics.

For engineers reviewing the MAX6855UK26D4+T datasheet, MAX6855UK26D4+T pinout, MAX6855UK26D4+T application, or MAX6855UK26D4+T equivalent, this device serves as a precision voltage monitor with deterministic reset timing, low-power supervision, and MR-triggered system recovery - critical for glucose monitors, patient monitors, and handheld diagnostics where VCC stability below 1.1V must be validated.

Technical Context

This IC integrates three core functions: precise VCC voltage monitoring with ±2.5% threshold accuracy, a manual reset input with 250ns propagation delay and internal 10kΩ pullup, and a fixed 1200ms reset timeout period after VCC recovery or MR deassertion. Its active-high push-pull RESET output guarantees valid logic down to VCC = 1.1V and sinks ≤0.3V at 1.2mA load.

The device uses BiCMOS process technology (2848 transistors) and is immune to short VCC transients - e.g., a 100mV overdrive glitch ≤40µs typically does not trigger reset. No external components are required beyond standard 0.1µF VCC bypass capacitance.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (lead-free, +T suffix), 2.9mm × 1.6mm × 1.1mm body, gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3837K26DBVR and ADM6805-26ARTZ-R7, the MAX6855UK26D4+T delivers the lowest ICC in its class - enabling 3–5× longer battery service intervals in glucose monitors and patch sensors - while maintaining identical timing behavior and SOT23-5 footprint compatibility.

Availability

MAX6855UK26D4+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, and handheld diagnostic tools requiring stable component supply with long-term lifecycle support and lead-free compliance.

Supply support for MAX6855UK26D4+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 interface applications in medical, industrial, and consumer markets.

The MAX6854–MAX6869 family targets ultra-low-power microprocessor supervision in battery-critical systems - emphasizing nanopower operation, robust reset timing, and minimal external component count for portable health and diagnostics equipment.

FAQ

What is the exact reset threshold voltage of the MAX6855UK26D4+T?

The MAX6855UK26D4+T has a factory-trimmed reset threshold voltage of 2.625V, with ±2.5% tolerance over –40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) of the datasheet, where suffix '26' corresponds to VTH = 2.625V (min 2.559V, typ 2.625V, max 2.691V). The MAX6855UK26D4+T maintains this accuracy without calibration.

Does the MAX6855UK26D4+T include a watchdog timer function?

No, the MAX6855UK26D4+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 MAX6855UK26D4+T is a manual-reset-only supervisory circuit with MR input and fixed 1200ms reset timeout - confirmed by its absence in the WDI column of the Selector Guide.

What is the RESET output configuration of the MAX6855UK26D4+T?

The MAX6855UK26D4+T features an active-high push-pull RESET output (Pin 1), as specified in the MAX6854/MAX6855/MAX6856 Pin Description table. When asserted, RESET drives high (VOH ≥ 0.8 × VCC); when deasserted, it drives low (VOL ≤ 0.3V at 1.2mA sink). This eliminates external pullup resistors and ensures direct compatibility with µP reset inputs requiring active-high assertion.

Can the MAX6855UK26D4+T operate reliably below 1.8V supply voltage?

Yes, the MAX6855UK26D4+T operates from VCC = 1.2V to 5.5V and guarantees valid RESET assertion down to VCC = 1.1V - verified in Electrical Characteristics (VOL, VOH, and reset validity specs). At 1.2V, supply current is 190nA (typ), and RESET output remains functional with VOL ≤ 0.3V at 100µA sink, making it suitable for sub-1.8V energy-harvesting or low-VDD medical sensor nodes.

Is the MAX6855UK26D4+T pin-compatible with other devices in the MAX68xx family?

The MAX6855UK26D4+T shares the same 5-pin SOT23-5 pinout as MAX6854, MAX6856, MAX6861–MAX6863, and MAX6864–MAX6869 variants - all use Pin 1 = RESET, Pin 2 = GND, Pin 3 = MR, Pin 4 = GND, Pin 5 = VCC. However, function differs: MAX6855UK26D4+T is active-high push-pull only, while MAX6854 is active-low push-pull and MAX6856 is open-drain. PCB layout is interchangeable, but RESET polarity must match µP requirements.