Analog Devices Inc./Maxim Integrated MAX6867UK26D3S+T

Overview

The MAX6867UK26D3S+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring ultra-low 170nA typical supply current, a factory-trimmed 2.625V reset threshold (suffix "26"), 150ms minimum reset timeout (suffix "D3"), and watchdog timer with 3.3s typical timeout (suffix "S"). It monitors VCC, responds to manual reset (MR), and triggers reset on watchdog timeout - designed for battery-powered medical and portable electronics requiring guaranteed reset validity down to VCC = +1.1V.

For engineers reviewing the MAX6867UK26D3S+T datasheet, MAX6867UK26D3S+T pinout, MAX6867UK26D3S+T application, or MAX6867UK26D3S+T equivalent, this page delivers verified functional identity, exact pin roles, confirmed timing parameters, real-world use cases in glucose monitors and patient monitors, and two validated alternative parts with documented technical and application differences.

Technical Context

The MAX6867UK26D3S+T integrates voltage monitoring, manual reset input (MR), and watchdog timer functionality in a single BiCMOS IC. Its reset assertion logic responds to VCC falling below 2.625V ±2.5%, MR low pulse ≥1µs, or WDI inactivity exceeding 3.3s (typ). The internal reset timeout is fixed at 150ms (min), and reset remains asserted for that duration after VCC recovery, MR deassertion, or watchdog expiration.

It uses a push-pull active-low RESET output referenced to VCC, supports operation from VCC = 1.2V to 5.5V, and guarantees valid reset down to VCC = +1.1V. Immunity to short VCC transients (e.g., ≤40µs at 100mV overdrive) ensures robustness in noisy portable systems without external components.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, lead-free, surface-mount. Pin 1 = WDI, Pin 2 = GND, Pin 3 = MR, Pin 4 = RESET, Pin 5 = VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6867UK26D3S+T, MAX6864UK26D3S+T offers identical supervision specs but inverted reset polarity, while TPS3836K26DBVR trades ultra-low power and watchdog capability for lower cost and simpler architecture - making each suitable for distinct design constraints in portable medical and consumer electronics.

Availability

MAX6867UK26D3S+T is available at Aetrix Electronics and suitable for glucose monitors, patient monitors, and MP3 players requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6867UK26D3S+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 MAX6854–MAX6869 family was designed specifically for ultra-low-power microprocessor supervision in battery-critical portable medical and consumer electronics, emphasizing nanopower operation, integrated watchdog, and guaranteed reset validity across wide VCC ranges.

FAQ

What is the exact reset threshold voltage of the MAX6867UK26D3S+T?

The MAX6867UK26D3S+T has a factory-trimmed reset threshold voltage of 2.625V, with ±2.5% tolerance over temperature (−40°C to +85°C). This value is defined by the "26" suffix in the part number and is confirmed in Table 2 (Threshold Suffix Guide) of the official datasheet. The threshold remains stable across operating conditions, enabling precise brownout detection on 2.7V–3.3V rails without external calibration.

Does the MAX6867UK26D3S+T include a watchdog timer, and what is its timeout period?

Yes, the MAX6867UK26D3S+T includes a watchdog timer with a typical timeout period of 3.3 seconds, indicated by the "S" suffix in the part number. The timer clears on any rising or falling edge at the WDI pin and expires if WDI remains static longer than 3.3s (min 1.5s, max 7.75s). This feature is explicitly documented in Table 3 (Watchdog Timeout) and applies to all MAX6867 variants.

What is the reset timeout period for the MAX6867UK26D3S+T, and how is it set?

The MAX6867UK26D3S+T has a fixed reset timeout period of 150ms (minimum), specified by the "D3" suffix. This value is factory-programmed and not user-adjustable. The timeout begins after VCC rises above 2.625V and MR is deasserted, and ensures the microprocessor completes power-up initialization before reset release - a requirement verified in the Electrical Characteristics table (tRP = D3).

What type of reset output does the MAX6867UK26D3S+T provide, and how is it configured?

The MAX6867UK26D3S+T provides a push-pull active-low RESET output (pin 4), as confirmed in the Pin Description section and Selector Guide. It drives low during reset assertion and high-impedance (not open-drain) when deasserted, eliminating the need for an external pullup resistor. This configuration is fixed per device variant and matches the MAX6864/MAX6865/MAX6866 series pinout.

Is the MAX6867UK26D3S+T compatible with 1.8V systems, and what is its minimum operating voltage?

Yes, the MAX6867UK26D3S+T operates from VCC = 1.2V to 5.5V and is fully functional at 1.8V, with supply current specified at 170nA (typ) under those conditions. Crucially, its reset output remains guaranteed valid down to VCC = +1.1V - a key specification confirmed in the Electrical Characteristics table - ensuring reliable reset assertion even during deep battery discharge in portable systems.