Analog Devices Inc./Maxim Integrated MAX699CWE+T

Overview

MAX699CWE+T from Maxim Integrated is a low-cost, single-chip power-on reset and watchdog controller for +5V microprocessor systems. It delivers a guaranteed 140ms RESET pulse on power-up, brownout (trip at 4.4V), and power-down, features an enabled watchdog timer with 1s timeout, and operates from 3.0V to 5.5V supply. Used in embedded controllers requiring reliable power sequencing and processor activity monitoring.

For engineers reviewing the MAX699CWE+T datasheet, MAX699CWE+T pinout, MAX699CWE+T application, or MAX699CWE+T equivalent, this page provides verified functional identity, confirmed SO-16 pin mapping, validated watchdog timing behavior, and real-world design context for μP reset supervision and fail-safe recovery.

Technical Context

The MAX699CWE+T integrates a precision voltage monitor with 40mV hysteresis and a monolithic watchdog timer that triggers RESET if WDI remains static >1s. Its dual RESET outputs-open-drain active-low RESET and active-high RESET-enable flexible interface to both NMOS and PMOS reset logic.

Unlike the PDIP version, the 16-pin wide SO package supports additional functions: dedicated WDO output and non-inverted RESET, all operating within 0°C to +70°C ambient range and rated for 4.4V–4.75V reset threshold window.

Key Specifications

Pinout & Package

MAX699CWE+T is housed in a 16-pin wide SO (SOIC-W) package, 0.3in body width, RoHS-compliant with lead-free finish (+ suffix). Pin 1 is top-left corner, pin 16 top-right, with GND on pins 3, 4, and 8.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power-on reset and watchdog controller applications.

Compared with MAX699CWE+T, MAX698CWE+T omits watchdog supervision entirely, while TPS3808G33DBVR targets 3.3V domains and lacks dual RESET outputs - making MAX699CWE+T uniquely suited for robust +5V μP systems needing both power integrity and software health monitoring.

Availability

MAX699CWE+T is available at Aetrix Electronics and suitable for industrial controllers, intelligent instruments, and embedded computing applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX699CWE+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, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX698/MAX699 product line delivers integrated power-on reset and watchdog supervision specifically for +5V microprocessor systems - reducing external component count while ensuring deterministic startup and runtime reliability.

FAQ

What is the function of the WDI pin on the MAX699CWE+T?

The WDI (Watchdog Input) pin on the MAX699CWE+T monitors microprocessor activity by requiring a logic transition at least once every 1 second. If WDI remains static beyond that timeout, the MAX699CWE+T asserts RESET and WDO. Leaving WDI unconnected disables the watchdog function, allowing the MAX699CWE+T to operate as a pure power-on reset supervisor.

Does the MAX699CWE+T support both 3.3V and 5V systems?

No - the MAX699CWE+T is specified for +5V supply monitoring with a 4.65V typical reset threshold and operates over 3.0V to 5.5V supply range. It is not designed for 3.3V rail supervision; for that, devices like the TPS3808G33DBVR are appropriate. The MAX699CWE+T must be used with a stable +5V source to ensure correct threshold behavior.

How does the dual RESET output on the MAX699CWE+T improve system design?

The MAX699CWE+T provides two independent RESET signals: open-drain active-low (pin 15) and push-pull active-high (pin 16). This eliminates external logic gates or level shifters needed to drive both NMOS and PMOS reset inputs. Designers can route each signal directly to appropriate subsystems - for example, using RESET (pin 15) for legacy peripherals and RESET (pin 16) for modern SoCs - improving noise immunity and timing margin.

Can the MAX699CWE+T replace the MAX699CPA in a new PCB layout?

No - the MAX699CWE+T (16-pin wide SO) is not pin-compatible with the MAX699CPA (8-pin PDIP). They differ in package size, pin count, and available functions: the SO version adds WDO and non-inverted RESET, while the PDIP version has only one RESET output and no WDO. A PCB redesign is required to migrate from MAX699CPA to MAX699CWE+T.

What is the minimum pulse width required on the WDI pin to prevent false watchdog timeout on the MAX699CWE+T?

The MAX699CWE+T does not specify a minimum WDI pulse width in its datasheet; it detects logic-level transitions (high-to-low or low-to-high). A clean edge meeting standard TTL/CMOS thresholds (≤0.8V low, ≥3.8V high) with >10ns rise/fall time is sufficient. The critical requirement is that at least one valid transition occurs within every 1-second window - not pulse duration, but toggle frequency.