Analog Devices Inc./Maxim Integrated MAX693AEWE+

Overview

The MAX693AEWE+ from Maxim Integrated is a microprocessor supervisory circuit designed for critical 5V power monitoring in embedded systems. It provides dual reset outputs (active-low RESET and active-high RESET), watchdog timer with selectable timeout (100ms/1.6s), battery switchover down to 1V VCC, and chip-enable gating with ≤10ns propagation delay. It operates across –40°C to +85°C and supports CMOS RAM write protection in industrial controllers and intelligent instruments.

For engineers reviewing the MAX693AEWE+ datasheet, MAX693AEWE+ pinout, MAX693AEWE+ application, or MAX693AEWE+ equivalent, key selection criteria include its 4.4V reset threshold, guaranteed RESET assertion at VCC = 1V, ±2% power-fail accuracy, and compatibility with MaxCap®/SuperCap™ backup capacitors in battery-backed memory retention designs.

Technical Context

The MAX693AEWE+ integrates a precision voltage monitor (4.4V typ reset threshold), dual-mode oscillator (internal 50kHz or external capacitor/clock), and bidirectional CE signal gating with 75Ω on-resistance and 10ns max propagation delay. Its battery switchover comparator activates when VCC falls below VBATT − 0.3V and remains valid down to VBATT = 2.0V.

It features two independent open-drain outputs: RESET (sinks 3.2mA @ 0.1V) and WDO (sinks 3mA @ 0.4V), both asserted during power-down or watchdog timeout. The PFI/PFO comparator operates independently with 1.25V threshold and 25μs response, supporting low-battery warning without affecting reset timing.

Key Specifications

Pinout & Package

MAX693AEWE+ is housed in a 16-pin Wide SO (SOIC-W) package with standard 0.3-inch body width and 1.27mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX693ACWE+, MAX693AEWE+ enables deployment in harsh environments; compared with MAX800MESE+, it offers larger pad layout margin and thermal mass in Wide SO, beneficial for high-reliability industrial power rails.

Availability

MAX693AEWE+ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, telecom remote terminal units, and energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX693AEWE+ 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 markets.

The MAX691A/MAX693A family was designed specifically for robust μP supervision in mission-critical 5V systems-emphasizing fail-safe reset timing, battery switchover integrity, and CE signal protection during power transients.

FAQ

What is the reset threshold voltage of the MAX693AEWE+?

The MAX693AEWE+ has a typical reset threshold voltage of 4.4V, with a guaranteed range of 4.25V to 4.50V across –40°C to +85°C. This value is specified for VCC falling conditions and includes 15mV hysteresis to prevent chatter near the threshold. The MAX693AEWE+ is part of the MAX693A variant group, distinct from the 4.65V-threshold MAX691A series.

Does the MAX693AEWE+ support battery backup operation below 1V VCC?

No-the MAX693AEWE+ guarantees RESET assertion validity down to VCC = 1V, but does not operate or assert reset below that level. When VCC drops below 1V, internal gate drive weakens, increasing RESET output saturation voltage. For full functionality down to 0V, an external 10kΩ pulldown resistor on the RESET pin is required, which ensures valid logic levels even at GND. This behavior is explicitly documented for the MAX693AEWE+ in the "RESET and RESET Outputs" section.

How is the watchdog timeout configured on the MAX693AEWE+?

The MAX693AEWE+ watchdog timeout is configured using the OSC SEL and OSC IN pins. With OSC SEL floating or tied to VOUT, the internal 50kHz oscillator sets a nominal 1.6s long timeout. Pulling OSC SEL low and connecting a capacitor (e.g., 47pF) from OSC IN to GND selects programmable timeouts per the formula (2.4/47pF × C) seconds. Driving OSC IN with an external clock yields fixed-cycle timeouts (e.g., 4096 cycles). All configurations apply directly to the MAX693AEWE+ without modification.

Can the MAX693AEWE+ be used with a 3.3V microprocessor?

The MAX693AEWE+ is designed for 5V systems: its VCC operating range is +4.5V to +5.5V, reset threshold is 4.4V, and all outputs (RESET, WDO, PFO) are referenced to VOUT/VCC-not 3.3V logic levels. While its open-drain outputs can be pulled to 3.3V externally, the device itself cannot monitor or supervise a 3.3V supply rail. For 3.3V supervision, Maxim's MAX6326 or similar 3.3V-specific supervisors should be used instead of the MAX693AEWE+.

What package type is used for the MAX693AEWE+?

The MAX693AEWE+ uses a 16-pin Wide SO (SOIC-W) package with 0.3-inch body width, 1.27mm lead pitch, and exposed pad option not included. The "EWE" suffix in the part number explicitly denotes the Wide SO variant, differentiated from "ESE" (Narrow SO) and "EUE" (TSSOP). This package provides higher thermal mass and mechanical robustness than Narrow SO, supporting reliable operation in industrial vibration and thermal cycling environments.