Analog Devices Inc./Maxim Integrated MAX824LEXK-T

Overview

MAX824LEXK-T from Maxim Integrated is a 5-pin SC70-packaged microprocessor supervisory circuit with active-low reset, active-high reset, and watchdog timer functions. It monitors +4.63V power supplies, asserts reset for ≥140ms on power-up, guarantees valid reset output down to VCC = 1V, and features 1.6s watchdog timeout. It is used in embedded controllers and critical µP monitoring systems where supply transient immunity and dual-reset polarity are required.

For engineers reviewing the MAX824LEXK-T datasheet, MAX824LEXK-T pinout, MAX824LEXK-T application, or MAX824LEXK-T equivalent, this page delivers verified functional identity, confirmed SC70-5 package mapping, validated 5-pin terminal roles, exact reset threshold (4.63V), guaranteed 1V reset validity, and two documented alternative parts with technical and application differences.

Technical Context

The MAX824LEXK-T implements a precision voltage comparator with 40ppm/°C temperature coefficient and 10mV hysteresis to detect VCC drops below 4.63V. Its dual-reset outputs (RESET and RESET) are complementary, enabling direct interface to µPs requiring either polarity without external inversion logic.

It integrates a watchdog timer that clears on any WDI edge (≥50ns pulse width) and times out after 1.12–2.40s if unrefreshed. The internal 52kΩ MR pullup resistor supports CMOS-level manual reset triggering without external components.

Key Specifications

Pinout & Package

MAX824LEXK-T is housed in a 5-pin SC70-5 package (3.0mm × 1.8mm, 0.95mm height), optimized for space-constrained PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX824LEXK-T, MAX824TEUK-T offers identical function in a thermally robust SOT23 package but requires PCB layout change, while TPS3808G33DBVR reduces feature count and power consumption but sacrifices watchdog capability and dual-reset flexibility needed for complex µP interfaces.

Availability

MAX824LEXK-T is available at Aetrix Electronics and suitable for embedded controllers, automotive ECUs, and portable medical devices requiring stable component supply, long-term lifecycle support, and lead-free compliance.

Supply support for MAX824LEXK-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 industrial, automotive, and computing applications, with emphasis on reliability and integration.

The MAX823/MAX824/MAX825 family was engineered to replace discrete reset solutions in µP-based systems, delivering combined reset, watchdog, and manual reset functions in minimal SC70/SOT23 footprints.

FAQ

What is the exact reset threshold voltage of MAX824LEXK-T?

The MAX824LEXK-T has a factory-trimmed reset threshold of 4.63V, with ±7mV tolerance over the full -40°C to +85°C temperature range. This value is specified in the Reset Threshold Table of the datasheet and applies directly to the L-suffix variant. The threshold remains stable with 40ppm/°C temperature coefficient, ensuring consistent brownout detection across operating conditions. MAX824LEXK-T uses this precise voltage to assert reset when VCC falls below specification, supporting reliable operation in +5V systems.

Does MAX824LEXK-T provide both active-low and active-high reset outputs?

Yes, MAX824LEXK-T provides complementary reset outputs: pin 1 (RESET) is active-low, and pin 3 (RESET) is active-high. These outputs are internally synchronized and guaranteed to be logically inverse across temperature and voltage. This dual-output architecture eliminates the need for external inverters when interfacing with µPs or FPGAs requiring different reset polarities. The design ensures simultaneous assertion and release, maintaining timing integrity in multi-domain systems using MAX824LEXK-T.

What is the watchdog timeout period for MAX824LEXK-T, and how is it triggered?

The MAX824LEXK-T watchdog timeout period is 1.12–2.40s, with a typical value of 1.6s. It is triggered when the WDI input (pin 4) remains static-either high or low-for longer than this interval. The timer clears on any rising or falling edge at WDI, including pulses as short as 50ns. If WDI is left unconnected, the internal driver disables the watchdog function. This behavior allows MAX824LEXK-T to monitor software execution flow without requiring continuous toggling, enhancing system reliability in safety-critical applications.

Can MAX824LEXK-T operate reliably during severe supply voltage droop?

Yes, MAX824LEXK-T guarantees valid reset output down to VCC = 1V, meaning RESET and RESET remain in their correct asserted states even as supply voltage collapses. This capability is critical for systems experiencing cranking events or battery sag, where other supervisors may release reset prematurely. The device continues monitoring until VCC recovers above 4.63V, then holds reset for ≥140ms. This behavior ensures deterministic µP restart in automotive and portable applications using MAX824LEXK-T.

What package type and footprint does MAX824LEXK-T use?

MAX824LEXK-T uses the SC70-5 package: a 5-pin, surface-mount outline measuring 3.0mm × 1.8mm with 0.95mm maximum height and 0.65mm pin pitch. It is tape-and-reel packaged with a 2500-piece minimum order quantity. The SC70 footprint enables high-density PCB layouts and is compatible with standard reflow soldering processes. This compact form factor distinguishes MAX824LEXK-T from its SOT23-5 variants and supports miniaturized designs where board space is constrained.