Analog Devices Inc./Maxim Integrated MAX825TEXK+T

Overview

MAX825TEXK+T from Maxim Integrated is a 5-pin microprocessor supervisory circuit with manual reset input and complementary active-high reset output, designed for precise power-supply monitoring in embedded systems. It features a 3.08V reset threshold, 140ms minimum power-on reset timeout, guaranteed RESET validity down to VCC = 1V, and operates at 2µA supply current (SC70 package) for battery-powered applications.

For engineers reviewing the MAX825TEXK+T datasheet, MAX825TEXK+T pinout, MAX825TEXK+T application, or MAX825TEXK+T equivalent, this device supports critical µP monitoring where low-power operation, transient immunity, and deterministic reset timing are required - especially in portable equipment and automotive subsystems with +3.0V–+3.6V rails.

Technical Context

The MAX825TEXK+T implements a precision voltage comparator with 5mV hysteresis and 40ppm/°C temperature coefficient to ensure stable reset assertion across -40°C to +85°C. Its internal reset timer guarantees ≥140ms assertion after VCC rise above 3.08V, and the manual reset input (MR) includes a 52kΩ internal pullup and 1.0µs minimum pulse width requirement.

This variant belongs to the MAX825 family and excludes watchdog functionality - distinguishing it from MAX823/MAX824 - while providing active-low and active-high RESET outputs simultaneously. MR-to-reset delay is 500ns, and RESET output sinks 1.2mA at VCC = VRST min (3.00V), ensuring reliable interface with modern µPs.

Key Specifications

Pinout & Package

MAX825TEXK+T is housed in a 5-pin SC70-5 package (2.0mm × 2.1mm, 0.65mm pitch), optimized for space-constrained PCB layouts in portable electronics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX825TEXK+T, MAX825TEUK+T offers identical supervision logic in a thermally rugged SOT23 package for harsh environments, while TPS3808G30DBVR reduces current draw slightly but sacrifices dual-output flexibility and requires layout adaptation for MR placement.

Availability

MAX825TEXK+T is available at Aetrix Electronics and suitable for portable medical sensors, automotive body control modules, industrial PLC I/O submodules, smart energy meters, and other applications requiring stable component supply with lead-free compliance and tape-and-reel packaging.

Supply support for MAX825TEXK+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 management, sensing, and interface applications in industrial, automotive, and computing markets.

The MAX825 series targets space- and power-constrained embedded systems requiring reliable, low-overhead µP supervision with minimal external components - particularly where dual-polarity reset signaling and ultra-low current are critical.

FAQ

What is the reset threshold voltage of the MAX825TEXK+T and how is it specified?

The MAX825TEXK+T has a factory-trimmed reset threshold of 3.08V, with ±1.5% tolerance over temperature (-40°C to +85°C). This value is guaranteed across the full operating range and appears in the Reset Threshold Table of the datasheet. The "T" suffix explicitly denotes the 3.08V variant, and the threshold is monitored continuously to assert RESET when VCC falls below this level.

Does the MAX825TEXK+T include a watchdog timer function?

No, the MAX825TEXK+T does not include a watchdog timer. It belongs to the MAX825 variant group, which provides manual reset input (MR) and complementary active-low/active-high RESET outputs - but omits the WDI pin and watchdog logic present in MAX823/MAX824. This makes MAX825TEXK+T ideal for applications requiring deterministic reset control without software supervision overhead.

What package type and lead finish does MAX825TEXK+T use?

The MAX825TEXK+T uses the SC70-5 package (2.0mm × 2.1mm, 0.65mm pitch) with lead-free (RoHS-compliant) finish. The "+T" suffix confirms lead-free construction, replacing the legacy "-T" designation. This compact, surface-mount package supports high-density PCB layouts and is compatible with standard reflow soldering profiles.

How does the manual reset input (MR) behave on the MAX825TEXK+T?

The MR input on MAX825TEXK+T is active-low, with an internal 52kΩ pullup resistor to VCC. A logic-low pulse ≥1.0µs asserts RESET (low) and holds it for the full reset timeout period (140–280ms) after MR returns high. MR can be driven by CMOS logic, open-drain outputs, or a simple SPST switch to GND - no external components are required for basic operation.

Can MAX825TEXK+T operate reliably during deep brownout conditions?

Yes, MAX825TEXK+T guarantees RESET output validity down to VCC = 1V, meaning it continues to assert correct reset state even as supply voltage collapses. This capability ensures safe µP shutdown or controlled recovery during severe brownouts, battery depletion, or backup power transitions - a key reliability feature confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables.