Analog Devices Inc./Maxim Integrated MAX825ZEXK+T

Overview

MAX825ZEXK+T from Maxim Integrated is a 5-pin SC70-packaged microprocessor supervisory circuit with manual reset input and complementary active-high reset output, designed for precision monitoring of +2.19V power supplies. It guarantees valid reset assertion down to VCC = 1V, features 140ms minimum power-on reset timeout, and draws only 2µA typical supply current in SC70 package. It is used in portable/battery-powered equipment requiring low-power, reliable µP reset control under brownout conditions.

For engineers reviewing the MAX825ZEXK+T datasheet, MAX825ZEXK+T pinout, MAX825ZEXK+T application, or MAX825ZEXK+T equivalent, key selection criteria include its 2.19V reset threshold (Z suffix), SC70-5 package, manual reset capability, active-high RESET output, and guaranteed operation at VCC ≥ 1V - all critical for low-voltage embedded systems with tight power budgets.

Technical Context

The MAX825ZEXK+T implements a precision voltage comparator with 40ppm/°C temperature coefficient and 5mV hysteresis to detect VCC drops below 2.19V. Its internal reset timer ensures a minimum 140ms reset pulse width after VCC recovery or MR release, and the manual reset input includes a 52kΩ internal pullup resistor enabling direct CMOS or switch interface without external components.

Unlike the MAX823/MAX824 variants, the MAX825ZEXK+T omits watchdog functionality but provides complementary reset outputs (RESET and RESET) for flexible µP interface - supporting both active-low and active-high reset logic families while maintaining full brownout immunity and transient rejection per the specified VCC glitch tolerance curve.

Key Specifications

Pinout & Package

MAX825ZEXK+T is housed in a 5-pin SC70-5 package (2.0mm × 1.25mm, 0.65mm pitch), compatible with standard pick-and-place equipment and reflow profiles for lead-free assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX825ZEXK+T, MAX825YEXK+T is functionally identical with identical electrical specs and package, differing only in top-side marking; TPS3808G12DBVR offers similar low-threshold supervision but lacks the complementary reset output and uses a larger SOT-23-5 footprint, limiting use in ultra-compact designs.

Availability

MAX825ZEXK+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered IoT nodes, industrial handheld terminals, and automotive body control modules requiring stable component supply across extended temperature ranges (-40°C to +85°C) and long production lifecycles.

Supply support for MAX825ZEXK+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, automotive, and communications applications.

The MAX823/MAX824/MAX825 family was designed specifically to replace discrete reset solutions in space- and power-constrained µP systems, delivering precision voltage monitoring, manual reset, and complementary reset outputs in minimal 5-pin SC70/SOT23 packages.

FAQ

What is the exact reset threshold voltage of the MAX825ZEXK+T?

The MAX825ZEXK+T has a factory-trimmed reset threshold of 2.19V, with ±15mV tolerance over the full -40°C to +85°C temperature range. This value is confirmed in the Reset Threshold Table of the official datasheet and applies specifically to the Z-suffix variant in SC70 package. The MAX825ZEXK+T maintains this accuracy with 40ppm/°C temperature coefficient and 5mV hysteresis to prevent chatter near threshold.

Does the MAX825ZEXK+T include a watchdog timer function?

No, the MAX825ZEXK+T does not include a watchdog timer. Per the Selector Guide and Functional Diagram, only MAX823 and MAX824 variants feature WDI input and watchdog timeout functionality. The MAX825ZEXK+T is specifically configured with manual reset input (MR) and complementary reset outputs (RESET and RESET), omitting watchdog circuitry to optimize for simplicity and lowest quiescent current in SC70 package.

What is the supply current specification for MAX825ZEXK+T at room temperature?

The MAX825ZEXK+T draws 2µA typical supply current at +25°C in SC70 package, as specified in the Electrical Characteristics table under "MAX825T/S/R/Z/Y Supply Current (SC70 Only)". This value is measured with MR unconnected and applies across the full operating voltage range (+2.25V to +2.75V). Maximum supply current is 6µA over temperature.

Can the MAX825ZEXK+T operate reliably when VCC drops below 2.0V?

Yes, the MAX825ZEXK+T guarantees correct reset output state down to VCC = 1V, as explicitly stated in the General Description and Electrical Characteristics sections. While its specified operating range is +2.25V to +2.75V, the reset comparator remains functional and asserts RESET low for VCC as low as 1V - enabling robust behavior during deep brownout or backup battery handover scenarios.

Is the MAX825ZEXK+T pin-compatible with other MAX825 variants like MAX825TEXK+T?

Yes, all MAX825 variants including MAX825ZEXK+T, MAX825TEXK+T, and MAX825REXK+T share identical SC70-5 pinout and package dimensions. The suffix letter (Z, T, R, etc.) denotes only the reset threshold voltage - not pin configuration or package type. All MAX825_EXK+T parts use pins 1–5 for RESET, GND, RESET, MR, and VCC respectively, with no functional or mechanical differences beyond threshold value.