Analog Devices Inc./Maxim Integrated MAX6855UK43D1+T

Overview

The MAX6855UK43D1+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, providing active-high push-pull reset output, manual reset input (MR), and factory-trimmed 4.300V reset threshold with 10ms minimum reset timeout. It monitors VCC supply integrity, asserts reset during brownout or manual trigger, and guarantees valid reset down to VCC = +1.1V - ideal for low-power portable medical devices and battery-powered instrumentation.

For engineers reviewing the MAX6855UK43D1+T datasheet, MAX6855UK43D1+T pinout, MAX6855UK43D1+T application, or MAX6855UK43D1+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing behavior, real-world power-supply immunity specs, and validated alternative options for design-in and BOM optimization.

Technical Context

This device belongs to the MAX6854–MAX6869 family of ultra-low-current (170nA typical) µP supervisors. It implements a precision voltage monitor with ±2.5% threshold accuracy, a fixed 10ms reset timeout after VCC recovery or MR release, and an internally pulled-up MR input requiring no external components. Unlike watchdog-equipped variants, the MAX6855UK43D1+T excludes WDI and CT pins, simplifying integration where only voltage monitoring and manual reset are needed.

The active-high push-pull RESET output drives high when asserted - directly compatible with µP reset inputs expecting active-high logic - and maintains guaranteed VOL ≤ 0.3V at ISINK = 1.2mA (VCC ≥ 2.38V). Its operation remains functional across -40°C to +85°C and supports supply voltages from 1.2V to 5.5V, with reset validity ensured down to VCC = 1.1V.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Compact footprint (2.9mm × 1.6mm × 1.1mm) optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with the MAX6855UK43D1+T, the TPS3837K33DBVR offers higher supply current and fixed 3.3V threshold, while the MAX6361KA29D3+T provides matching 10ms timeout but targets 2.93V rails and active-low signaling - making the MAX6855UK43D1+T uniquely suited for 4.3V systems demanding ultra-low ICC and active-high reset.

Availability

MAX6855UK43D1+T is available at Aetrix Electronics and suitable for portable medical devices, battery-powered instrumentation, and low-power industrial sensors requiring stable component supply, long-lifecycle support, and lead-free compliance.

Supply support for MAX6855UK43D1+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, mixed-signal, and power-management ICs for demanding industrial, medical, and communications applications.

The MAX6854–MAX6869 product line delivers nanopower supervisory circuits targeting battery-critical portable electronics - emphasizing ultra-low ICC, guaranteed reset validity at low VCC, and minimal external component count.

FAQ

What is the exact reset threshold voltage of the MAX6855UK43D1+T?

The MAX6855UK43D1+T has a factory-trimmed reset threshold of 4.300V, 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 "43" corresponds to VTH = 4.300V (typ). The MAX6855UK43D1+T maintains this specification without calibration or external adjustment.

Does the MAX6855UK43D1+T include a watchdog timer function?

No, the MAX6855UK43D1+T does not include a watchdog timer. Per the Selector Guide and Pin Description sections, only MAX6864–MAX6869 variants feature WDI functionality. The MAX6855UK43D1+T is configured exclusively for voltage monitoring and manual reset, with Pins 1 (RESET), 2/4 (GND), 3 (MR), and 5 (VCC) - no WDI or CT pin present.

What is the reset timeout period for the MAX6855UK43D1+T?

The MAX6855UK43D1+T has a minimum reset timeout period of 10ms, denoted by suffix "D1" in the ordering code. This is confirmed in Table 4 (Reset Timeout Periods), where D1 specifies 10ms (min), 15ms (typ), and 25ms (max). The timeout begins after VCC rises above the 4.300V threshold or MR is released.

Is the RESET output of the MAX6855UK43D1+T active-high or active-low?

The MAX6855UK43D1+T features an active-high push-pull RESET output, as specified in the MAX6854/MAX6855/MAX6856 Pin Description table. When reset is asserted, RESET drives high; when deasserted, it drives low. This differs from the MAX6854 (active-low) and MAX6856 (open-drain active-low) variants in the same family.

What package type and lead finish does the MAX6855UK43D1+T use?

The MAX6855UK43D1+T uses a 5-pin SOT23-5 package with lead-free (RoHS-compliant) finish, indicated by the "+T" suffix per Maxim's ordering convention. The package dimensions are 2.9mm × 1.6mm × 1.1mm, and thermal characteristics support continuous operation at up to +85°C ambient.