Analog Devices Inc./Maxim Integrated MAX708SMJA

Overview

MAX708SMJA from Maxim Integrated is a precision microprocessor supervisory circuit designed for critical +3V/+3.3V power monitoring in high-reliability embedded systems. It provides dual active-high and active-low reset outputs (RESET and RESET), a 2.63V reset threshold, 200ms reset pulse width, and a 1.25V power-fail comparator input (PFI) - enabling brownout detection and orderly shutdown in aerospace-grade applications.

For engineers reviewing the MAX708SMJA datasheet, MAX708SMJA pinout, MAX708SMJA application, or MAX708SMJA equivalent, this device serves as a military-temperature-grade supervisory solution with guaranteed reset assertion down to VCC = 1V, CERDIP packaging for hermetic reliability, and no watchdog timer - distinguishing it from MAX706-series variants.

Technical Context

The MAX708SMJA implements a dual-reset architecture with independent RESET (active-high) and RESET (active-low) outputs, both asserted when VCC falls below 2.63V or MR is pulled low. Its internal timing generator guarantees 200ms reset pulse width after VCC recovery and ensures reset remains valid down to VCC = 1V - critical for deterministic startup in harsh environments.

It integrates a precision 1.25V reference for the PFI comparator, supporting external resistive dividers to monitor auxiliary supplies (e.g., +12V or negative rails), while PFO delivers an active-low power-fail warning signal. Unlike MAX706 variants, MAX708SMJA omits the watchdog timer and WDI/WDO pins entirely - simplifying design where system-level supervision suffices.

Key Specifications

Pinout & Package

MAX708SMJA is housed in an 8-pin CERDIP (ceramic dual in-line package) with J8-2 footprint, rated for –55°C to +125°C operation and compliant with MIL-STD-883 processing requirements.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX708RMJA, MAX708SMJA offers enhanced reliability screening per MIL-STD-883, while versus MAX708SEUA it trades µMAX's compactness for CERDIP's hermetic robustness and extended temperature capability - making it the sole choice for space-constrained yet environmentally demanding applications requiring zero moisture ingress.

Availability

MAX708SMJA is available at Aetrix Electronics and suitable for aerospace power sequencing, downhole telemetry systems, military radios, and railway signaling controllers requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX708SMJA 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 demanding industrial, automotive, and communications applications.

The MAX708 family was engineered specifically for high-reliability microprocessor supervision in environments where power integrity, temperature resilience, and deterministic reset behavior are non-negotiable - targeting aerospace, defense, and energy exploration markets.

FAQ

What is the reset threshold voltage of the MAX708SMJA?

The MAX708SMJA has a fixed reset threshold of 2.63V (VCC falling). This value is factory-trimmed and guaranteed over the full –55°C to +125°C temperature range. The device asserts both RESET and RESET outputs when VCC drops below this threshold and maintains reset for 200ms after VCC rises above it. This precise threshold ensures compatibility with standard +3V systems while providing sufficient hysteresis against noise-induced false triggering.

Does the MAX708SMJA include a watchdog timer function?

No, the MAX708SMJA does not include a watchdog timer. Unlike the MAX706 series, the MAX708 family replaces the watchdog input (WDI) and watchdog output (WDO) pins with dual reset outputs (RESET and RESET). The MAX708SMJA pinout omits WDI and WDO entirely - confirmed by its Pin Description table and functional diagram. This makes it ideal for applications where system-level supervision is handled externally or unnecessary.

What package type and temperature range does the MAX708SMJA use?

The MAX708SMJA is packaged in an 8-pin CERDIP (ceramic dual in-line package) with J8-2 footprint and is specified for operation from –55°C to +125°C. This hermetically sealed ceramic package meets MIL-STD-883 requirements for moisture resistance, thermal shock endurance, and long-term reliability in aerospace and defense applications - distinguishing it from plastic SO or µMAX variants.

How does the MAX708SMJA handle power-fail detection?

The MAX708SMJA uses its PFI (power-fail input) pin, referenced to an internal 1.25V comparator, to detect falling voltage on auxiliary supplies. When the voltage at PFI drops below 1.25V, the PFO (power-fail output) goes active-low. Designers connect PFI to a resistive divider from the supply being monitored - for example, a +12V rail - allowing early warning before main supply collapse. PFO can drive interrupts or backup power enable lines directly.

Can the MAX708SMJA operate with supply voltages below 3V?

Yes, the MAX708SMJA operates from 1.2V to 5.5V and guarantees RESET assertion down to VCC = 1V - a key differentiator for brownout resilience. At VCC = 1.2V, it maintains functional reset generation and PFI comparator accuracy. This capability supports battery-backed systems where voltage sags occur during cold cranking or deep discharge, ensuring µP remains held in reset until stable operating conditions return.