Analog Devices Inc./Maxim Integrated MAX695CWE+T

Overview

MAX695CWE+T from Maxim Integrated is a 16-pin microprocessor supervisory circuit providing reset generation, adjustable watchdog timer, battery backup switchover, power-fail detection (1.3V threshold), and chip-enable gating for CMOS RAM/EEPROM protection. It operates with 4.75V–5.5V VCC, supports 2.0V–4.25V backup battery input, delivers 50mA VOUT, and features 200ms reset timeout and 1.6s/100ms selectable watchdog periods - used in automotive control units and industrial controllers requiring reliable brownout recovery.

For engineers reviewing the MAX695CWE+T datasheet, MAX695CWE+T pinout, MAX695CWE+T application, or MAX695CWE+T equivalent, this page delivers verified functional identity, exact pin roles, real-world timing values (200ms reset, 1.6s watchdog), battery switchover hysteresis (20mV), and CE gating behavior under low-VCC conditions - all confirmed from Maxim's official MAX690–MAX695 family datasheet Rev 5.

Technical Context

The MAX695CWE+T integrates five core supervisory functions: precision reset generation with 4.65V ±150mV threshold and 200ms timeout; dual-mode watchdog (internal oscillator or external clock/capacitor); bidirectional battery switchover with 70mV power-up / 50mV power-down thresholds and 20mV hysteresis; 1.3V PFI comparator with PFO output; and CE IN/CE OUT gating logic that forces CE OUT high when VCC drops below 4.65V to prevent RAM corruption.

Its 16-pin SOIC-W (wide-body) package hosts dedicated terminals for BATT ON (active-high battery-switch indicator), LOW LINE (VCC-fall indicator), WDO (watchdog fault flag), OSC SEL/OSC IN (timing configuration), and dual RESET outputs (active-low and active-high). All timing parameters - including reset delay, watchdog period, and CE propagation delay (50–200ns) - are fully adjustable via OSC SEL and OSC IN pin states per Table 1 of the datasheet.

Key Specifications

Pinout & Package

MAX695CWE+T uses a 16-pin SOIC-W (Wide) package (body width 7.5mm), RoHS-compliant, rated for –40°C to +85°C (E-suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX695CWE+T, MAX695CPE+ omits 6 critical pins (CE IN/OUT, BATT ON, LOW LINE, WDO, OSC SEL/IN) and cannot protect RAM or adjust timing, while TPS3823MPW provides only reset - making both unsuitable as functional replacements where battery switchover, CE gating, or configurable watchdog are design requirements.

Availability

MAX695CWE+T is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC modules, medical infusion pump controllers, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX695CWE+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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing applications.

The MAX690–MAX695 family was designed specifically for microprocessor system supervision - integrating reset, watchdog, battery switchover, power-fail detection, and RAM write protection into a single 16-pin IC to eliminate discrete solutions and improve reliability.

FAQ

What is the reset threshold voltage of the MAX695CWE+T?

The MAX695CWE+T has a guaranteed reset threshold of 4.65V, with a minimum of 4.5V and maximum of 4.75V across the full operating temperature range. This 4.65V threshold is optimized for +5V ±5% power supplies and ensures reliable µP reset assertion during brownout conditions. The threshold includes 40mV hysteresis to prevent chatter near the trip point, and the reset pulse remains active for 200ms after VCC recovers - a value confirmed in the Electrical Characteristics table of the MAX690–MAX695 datasheet Rev 5.

Does the MAX695CWE+T support adjustable watchdog timeout periods?

Yes, the MAX695CWE+T supports two selectable watchdog timeout periods: 100ms (short) and 1.6s (long), configured via the OSC SEL and OSC IN pins. When OSC SEL is floating and OSC IN is low, the 100ms mode activates after the first WDI transition post-reset; otherwise, the default is 1.6s. External clock or capacitor-based timing is also supported per Table 1. This adjustability is exclusive to the 16-pin MAX691/MAX693/MAX695 variants - the 8-pin MAX690/692/694 have fixed 1.6s timeout.

How does the MAX695CWE+T protect CMOS RAM during power failure?

The MAX695CWE+T protects CMOS RAM using its CE IN/CE OUT gating function: CE OUT follows CE IN only when VCC ≥ 4.65V; if VCC drops below that threshold, CE OUT is forced high - disabling RAM writes regardless of CE IN state. This hardware-enforced write protection prevents data corruption during power-up, brownout, or shutdown. The CE propagation delay is 50–200ns, ensuring immediate response. This feature is absent in the 8-pin MAX690/692/694 and is a key differentiator of the MAX695CWE+T.

What is the battery switchover behavior of the MAX695CWE+T?

The MAX695CWE+T switches VOUT between VCC and VBATT based on relative voltage: VOUT connects to VBATT when VCC falls 50mV below VBATT (power-down), and reverts to VCC when VCC rises 70mV above VBATT (power-up). This 20mV hysteresis prevents oscillation. In backup mode, VOUT delivers up to 250µA at VBATT – 0.1V, with only 1µA typical supply current - enabling multi-year operation from a CR2032 coin cell. The BATT ON pin signals the switch event and can drive an external PNP transistor for higher load currents.

Can the MAX695CWE+T monitor a non-5V power rail?

Yes, the MAX695CWE+T can monitor non-5V rails using its PFI input and internal 1.3V reference. By connecting PFI to a resistor divider from the target rail (e.g., 3.3V, 12V, or unregulated input), the PFO output asserts low when the divided voltage falls below 1.3V - providing programmable power-fail warning. For example, a 3.3V rail can be monitored with a 1.3V/3.3V ≈ 39% divider ratio. The PFI input draws only ±25nA, introducing negligible loading. This capability is explicitly documented in the "Power-Fail Detector" section and Figure 1 of the MAX690–MAX695 datasheet.