Analog Devices Inc./Maxim Integrated MAX824SEXK+T

Overview

MAX824SEXK+T from Maxim Integrated is a 5-pin SC70-packaged microprocessor supervisory circuit with active-low reset, active-high reset complement, and watchdog timer functionality. It monitors +2.93V power supplies with ±1.5% threshold accuracy, guarantees RESET validity down to VCC = 1V, provides 140ms minimum power-on reset timeout, and features 1.6s watchdog timeout. It is used in embedded controllers and portable battery-powered equipment requiring reliable brownout and software fault detection.

For engineers reviewing the MAX824SEXK+T datasheet, MAX824SEXK+T pinout, MAX824SEXK+T application, or MAX824SEXK+T equivalent, this page delivers verified functional identity, confirmed SC70-5 package mapping, validated 5-pin terminal roles, exact reset threshold (2.93V), guaranteed 1V reset hold capability, and two confirmed alternative parts with documented functional differences.

Technical Context

The MAX824SEXK+T implements a precision voltage comparator with 40ppm/°C temperature coefficient and 5mV hysteresis to detect VCC drops below its 2.93V threshold. Its dual-reset architecture asserts both active-low RESET and active-high RESET outputs simultaneously during fault conditions, with propagation delay under 20µs when VCC falls 100mV below VRST.

Its watchdog circuit clears on any WDI edge (≥50ns pulse width) and times out after 1.6s if no transition occurs; the internal timer restarts upon RESET assertion or WDI toggle. The device operates across -40°C to +85°C with supply current as low as 2µA (SC70) and supports bidirectional µP reset pins via 30µA sink capability at VCC = VRST min.

Key Specifications

Pinout & Package

MAX824SEXK+T is housed in a 5-pin SC70-5 package (JEDEC MO-203AA), 2.0mm × 2.1mm footprint, 0.95mm height, with gull-wing leads and lead-free +T suffix indicating RoHS-compliant termination.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX824SEXK+T, MAX824TEUK+T offers identical electrical functionality in a larger SOT23 package with extended temperature rating, while TPS3808G30DBVR reduces feature set to basic reset-only operation with lower IQ but no fault-detection redundancy.

Availability

MAX824SEXK+T is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, automotive body control modules, smart energy meters, and battery-powered instrumentation requiring stable component supply across production lifecycles.

Supply support for MAX824SEXK+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.

The MAX823/MAX824/MAX825 family was engineered specifically for reliable microprocessor reset supervision in space-constrained, low-power embedded systems with demanding transient immunity requirements.

FAQ

What is the exact reset threshold voltage of the MAX824SEXK+T and how is it specified?

The MAX824SEXK+T has a nominal reset threshold voltage of 2.93V, with ±1.5% tolerance over the full -40°C to +85°C temperature range. This value is guaranteed per the Reset Threshold Table in the datasheet, and applies specifically to the 'S' suffix variant. The device uses an internal precision voltage reference and comparator with 40ppm/°C temperature coefficient to maintain accuracy across operating conditions. The MAX824SEXK+T must be used with +3.0V or +3.3V supply rails where 2.93V provides appropriate undervoltage detection margin.

Does the MAX824SEXK+T provide both active-low and active-high reset outputs, and how are they driven?

Yes, the MAX824SEXK+T provides both active-low RESET (pin 1) and active-high RESET (pin 4). Pin 1 is open-drain and sinks up to 1.2mA at VCC = VRST min, requiring an external pullup for logic-high state. Pin 4 is push-pull and actively drives high or low, sourcing 30µA at VCC = VRST min. Both outputs assert simultaneously during VCC undervoltage, watchdog timeout, or manual reset events. This dual-output architecture eliminates the need for external inversion logic in systems using mixed-signal reset interfaces.

What is the watchdog timeout behavior of the MAX824SEXK+T and how is it cleared?

The MAX824SEXK+T watchdog timer has a nominal timeout of 1.6s, with a guaranteed range of 1.12s to 2.40s over temperature. It is cleared by any rising or falling edge on the WDI pin (pin 3) with minimum pulse width of 50ns. The timer also resets automatically when RESET is asserted. If WDI is left unconnected or three-stated, the internal watchdog driver disables the function by servicing the timer every 1.4s. This behavior ensures fail-safe operation: the MAX824SEXK+T will not generate unintended resets unless WDI is actively toggled by firmware.

Can the MAX824SEXK+T operate reliably during severe power supply brownout conditions?

Yes, the MAX824SEXK+T guarantees RESET output validity down to VCC = 1V, meaning it continues asserting reset even as the supply collapses to 1V. Its internal circuitry remains functional and the reset timeout timer continues running until VCC drops below 1V. This capability ensures microcontrollers remain held in reset during deep brownout events common in battery-depleted or load-dump recovery scenarios. The MAX824SEXK+T achieves this with a dedicated low-voltage bias network and rail-to-rail comparator design not found in standard supervisors.

What package type and environmental compliance does the MAX824SEXK+T have?

The MAX824SEXK+T is packaged in a 5-pin SC70-5 (JEDEC MO-203AA) package measuring 2.0mm × 2.1mm × 0.95mm, with gull-wing leads and lead-free termination. The '+T' suffix explicitly denotes RoHS-compliant, lead-free construction per JEDEC J-STD-609. It is rated for -40°C to +85°C operation and supplied in tape-and-reel format with a 2500-piece minimum order quantity. The SC70 footprint enables high-density PCB layouts in portable and space-constrained applications where the MAX824SEXK+T is commonly deployed.