Analog Devices Inc./Maxim Integrated MAX6863UK26+T

Overview

The MAX6863UK26+T from Maxim Integrated is a nanopower microprocessor supervisory circuit in a 5-pin SOT23 package, featuring manual reset input (MR), pin-selectable reset timeout (10ms/150ms min), and a factory-trimmed 2.625V reset threshold. It asserts an active-low open-drain RESET output during VCC brownout, MR assertion, or watchdog timeout-guaranteed valid down to VCC = 1.1V. Designed for ultra-low-power portable medical and consumer devices like glucose monitors and MP3 players.

For engineers reviewing the MAX6863UK26+T datasheet, MAX6863UK26+T pinout, MAX6863UK26+T application, or MAX6863UK26+T equivalent, key selection criteria include its 170nA typical supply current, 2.625V ±2.5% reset threshold, 10ms/150ms pin-selectable timeout, immunity to short VCC transients (<40µs at 100mV overdrive), and compatibility with 1.2V–5.5V supply rails.

Technical Context

The MAX6863UK26+T integrates voltage monitoring, manual reset control, and configurable reset timing into a single BiCMOS IC. Its CT pin selects between two factory-validated timeout options (D1: 10ms min or D3: 150ms min), while MR provides asynchronous reset initiation with 250ns delay and 1µs minimum pulse width.

Unlike watchdog-equipped variants (e.g., MAX6864–MAX6869), the MAX6863UK26+T omits WDI functionality and watchdog timer circuitry-confirmed by its absence in the Selector Guide and Pin Description tables. Its open-drain RESET output requires an external pullup and supports logic-level translation across supply domains up to 5.5V.

Key Specifications

Pinout & Package

MAX6863UK26+T uses a lead-free 5-pin SOT23 package (2.9mm × 1.6mm × 1.1mm height) with gull-wing leads. Pin 1 is CT (Reset Timeout Select), Pin 2 is GND, Pin 3 is MR (Manual Reset Input), Pin 4 is RESET (active-low open-drain output), and Pin 5 is VCC (supply monitor input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3836K26DBVR and MAX6315US26D3+, the MAX6863UK26+T uniquely combines ultra-low 170nA ICC, pin-selectable 10ms/150ms timeout, and MR support in an open-drain configuration-making it optimal for long-life, field-serviceable portable medical devices.

Availability

MAX6863UK26+T is available at Aetrix Electronics and suitable for glucose monitors, portable audio players, wireless patient loggers, and low-power industrial sensors requiring stable component supply across extended production lifecycles.

Supply support for MAX6863UK26+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 MAX6863UK26+T belongs to the MAX6854–MAX6869 nanopower supervisory family, engineered specifically for battery-constrained portable electronics requiring guaranteed reset behavior, minimal quiescent current, and flexible timing configuration without external components.

FAQ

What is the exact reset threshold voltage of the MAX6863UK26+T?

The MAX6863UK26+T has a factory-trimmed reset threshold of 2.625V with ±2.5% tolerance over -40°C to +85°C. This value is confirmed in Table 2 (Threshold Suffix Guide) where suffix "26" corresponds to VTH = 2.625V, and is validated in the Electrical Characteristics table under "VCC Reset Threshold (VTH)". The MAX6863UK26+T maintains this accuracy without calibration or external components.

Does the MAX6863UK26+T include a watchdog timer function?

No, the MAX6863UK26+T does not include a watchdog timer. Per the Selector Guide and Pin Description sections, MAX6863 is explicitly listed without WDI (Watchdog Input) functionality, and its pinout omits WDI-unlike MAX6864–MAX6869 variants. The MAX6863UK26+T provides only voltage monitoring, manual reset (MR), and pin-selectable reset timeout (CT), making it suitable for applications where software supervision is handled externally.

How is the reset timeout period selected on the MAX6863UK26+T?

The MAX6863UK26+T uses the CT (pin 1) to select between two minimum reset timeout periods: connect CT to GND for 10ms (D1), or to VCC for 150ms (D3). This selection is confirmed in Table 1 ("MAX6861/MAX6862/MAX6863 Reset Timeout Period Selection") and the MAX6863-specific Pin Description. The timeout is factory-validated and requires no external timing components-enabling flexible timing without BOM changes.

What type of RESET output does the MAX6863UK26+T provide?

The MAX6863UK26+T provides an active-low open-drain RESET output on pin 4. As specified in the MAX6863 Pin Description and Selector Guide, it requires an external pullup resistor and supports interfacing to µP reset inputs powered by voltages up to 5.5V. This differs from push-pull variants (e.g., MAX6854/MAX6855) and enables level-shifting across supply domains-a key feature for mixed-voltage portable systems using the MAX6863UK26+T.

Is the MAX6863UK26+T compatible with the TPS3836/TPS3837/TPS3838 series?

Yes, the MAX6863UK26+T is pin-compatible with the TPS3836/TPS3837/TPS3838 series per the Features section, which states: "Pin Compatible to the TPS3836/TPS3837/TPS3838 (MAX6861/MAX6862/MAX6863)". However, functional differences exist: MAX6863UK26+T offers CT-selectable timeout and 170nA ICC versus TPS3836's fixed timeout and ~1.2µA ICC. Layout reuse is possible, but firmware timing assumptions must be verified.