Analog Devices Inc./Maxim Integrated MAX6854UK31D3+T

Overview

The MAX6854UK31D3+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 150ms minimum reset timeout. It asserts an active-low open-drain RESET output when VCC drops below its factory-trimmed 3.075V threshold (±2.5%), during MR assertion, or after power-up/brownout - guaranteeing valid reset down to VCC = +1.1V. It targets ultra-low-power portable medical and consumer devices such as glucose monitors and MP3 players.

For engineers reviewing the MAX6854UK31D3+T datasheet, MAX6854UK31D3+T pinout, MAX6854UK31D3+T application, or MAX6854UK31D3+T equivalent, this page delivers verified functional identity, exact reset threshold and timeout values, confirmed SOT23-5 pin mapping, real-world timing behavior under temperature variation, and validated alternative options for low-current supervisory design.

Technical Context

This device implements a precision bandgap-based voltage monitor with 2.5% threshold tolerance and 0.5% hysteresis, coupled to a digital timeout counter that enforces a guaranteed minimum 150ms (typ. 225ms) reset pulse width after VCC recovery or MR release. Its 170nA typical supply current at 1.8V enables multi-year battery life in always-on wearable sensors.

The MR input features internal 10kΩ pullup, 1µs minimum pulse width support, and 200ns glitch rejection - enabling direct interface with momentary switches or CMOS logic without external debounce. The open-drain RESET output supports level-shifting up to 5.5V and requires no external components beyond a pullup resistor.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount, footprint compatible with industry-standard 5-pin SOT23 layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K33DBVR and MAX6361KA31D3+T, the MAX6854UK31D3+T uniquely balances ultra-low 170nA ICC, factory-trimmed 3.075V threshold, integrated MR input, and open-drain output - making it optimal for battery-critical portable medical and consumer electronics where both precision and longevity are mandatory.

Availability

MAX6854UK31D3+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, and smart pagers requiring stable component supply across extended production lifecycles and global regulatory compliance.

Supply support for MAX6854UK31D3+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 industrial, medical, and communications markets.

The MAX6854UK31D3+T belongs to the nanopower µP supervisory family engineered specifically for battery-operated medical and portable electronics demanding sub-µA quiescent current and guaranteed reset validity down to 1.1V.

FAQ

What is the exact reset threshold voltage of the MAX6854UK31D3+T?

The MAX6854UK31D3+T has a factory-trimmed reset threshold of 3.075V, with ±2.5% tolerance over -40°C to +85°C. This value is confirmed by the "31" suffix in the part number per Maxim's Threshold Suffix Guide (Table 2), and is validated in the Electrical Characteristics table where VTH = 3.075V (min 2.998V, max 3.152V). The MAX6854UK31D3+T uses this precise threshold to reliably detect brownout in 3.3V systems.

Does the MAX6854UK31D3+T include a watchdog timer function?

No, the MAX6854UK31D3+T does not include a watchdog timer. Per the Selector Guide and Pin Configurations, only MAX6864–MAX6869 variants feature WDI input; the MAX6854 series provides voltage monitoring and manual reset only. The MAX6854UK31D3+T pinout omits WDI, and its functional diagram excludes watchdog circuitry - confirming it is a dedicated reset supervisor without timer functionality.

What is the reset timeout period for the MAX6854UK31D3+T?

The MAX6854UK31D3+T has a fixed minimum reset timeout period of 150ms, with typical value 225ms and maximum 300ms (per Table 4, D3 option). This is encoded in the "D3" suffix of the part number and verified in the Electrical Characteristics table under tRP. The timeout begins after VCC rises above the 3.075V threshold and MR is deasserted, ensuring sufficient time for µP clock stabilization and register initialization.

Is the RESET output of the MAX6854UK31D3+T push-pull or open-drain?

The MAX6854UK31D3+T features an open-drain active-low RESET output, as confirmed by the Pin Description table (Pin 1 = RESET, open-drain or push-pull) and Selector Guide (MAX6854 row shows "√" under "OPEN-DRAIN ACTIVE LOW"). This configuration requires an external pullup resistor and enables level-shifting to higher-voltage logic domains - a key differentiator from push-pull variants like MAX6855.

Can the MAX6854UK31D3+T operate down to 1.2V supply voltage?

Yes, the MAX6854UK31D3+T operates across VCC = 1.2V to 5.5V, and its reset function remains fully guaranteed down to VCC = +1.1V per the Electrical Characteristics table. At 1.2V, supply current is 190nA (typ), and RESET output low voltage is specified at ≤0.3V with 50µA sink current - enabling robust operation in single-cell lithium or alkaline systems where voltage sags near end-of-life.