Analog Devices Inc./Maxim Integrated MAX695CPE+

Overview

The MAX695CPE+ from Maxim Integrated is a 16-pin microprocessor supervisory circuit providing precision reset generation, adjustable watchdog timer, battery backup switchover, power-fail detection, and chip-enable gating for CMOS RAM/EEPROM. It features a 4.65V reset threshold, 200ms reset timeout, 1.6s/100ms selectable watchdog period, 1.3V PFI comparator, and operates from 4.75V to 5.5V VCC with 2.0V–4.25V VBATT support. It is used in industrial controllers and intelligent instruments requiring reliable power monitoring and data retention.

For engineers reviewing the MAX695CPE+ datasheet, MAX695CPE+ pinout, MAX695CPE+ application, or MAX695CPE+ equivalent, key selection criteria include its 16-pin PDIP package, dual-mode watchdog timing, CE OUT write-protection logic, BATT ON output for external transistor drive, and compatibility with +5V systems requiring brownout immunity and nonvolatile memory safeguarding.

Technical Context

The MAX695CPE+ integrates five core supervisory functions: (1) precision voltage monitoring with 4.65V ±75mV reset threshold and 40mV hysteresis; (2) adjustable reset timeout (200ms nominal) via internal oscillator or external clock/capacitor; (3) dual-range watchdog timer (100ms or 1.6s) with WDI transition detection and WDO fault indication; (4) automatic VCC/VBATT switchover with 70mV rising-edge and 50mV falling-edge thresholds; and (5) CE IN/CE OUT gating that forces CE OUT high during low-VCC events to prevent erroneous RAM writes.

Its architecture includes an internal 6.55kHz oscillator, a 1.3V reference-based PFI comparator with ±25nA input current, and dedicated outputs-RESET (active-low), RESET (active-high), WDO, BATT ON, LOW LINE, and PFO-each with defined sink/source capabilities (e.g., BATT ON sinks 25mA, RESET sinks 1.6mA). All timing and voltage thresholds are specified across 0°C to +70°C (C-suffix).

Key Specifications

Pinout & Package

MAX695CPE+ is housed in a 16-pin plastic DIP (PDIP) package with 0.3-inch width, through-hole mounting, and industry-standard pin spacing. Pin 1 is marked with a notch or dot; pin numbering proceeds counterclockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX695CPE+, MAX695CSE+ offers identical functionality in SOIC-16 for volume production, while MAX693CPE+ trades reset threshold margin for wider supply tolerance-making MAX695CPE+ the optimal choice for new designs targeting 4.75V–5.5V nominal 5V rails with strict reliability requirements.

Availability

MAX695CPE+ is available at Aetrix Electronics and suitable for industrial controllers, intelligent instruments, automotive body control modules, and critical microprocessor power monitoring applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for MAX695CPE+ 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, communications, and computing markets.

The MAX690–MAX695 family was designed to consolidate power supervision, battery backup, watchdog, and memory protection functions into single-chip solutions for microprocessor-based systems demanding reliability, low power, and board-space efficiency.

FAQ

What is the reset threshold voltage of the MAX695CPE+ and how is it guaranteed across temperature?

The MAX695CPE+ has a guaranteed reset threshold of 4.65V with ±75mV tolerance over the full 0°C to +70°C operating range. This specification is ensured by laser-trimmed internal resistors and a precision bandgap reference. The device maintains 40mV of hysteresis to prevent chatter during slow VCC transitions. At +25°C, typical threshold is 4.65V; minimum is 4.5V and maximum is 4.75V per the datasheet's Electrical Characteristics table.

How does the MAX695CPE+ handle battery backup switchover, and what is the switchover threshold accuracy?

The MAX695CPE+ performs automatic switchover between VCC and VBATT using an internal comparator with 70mV rising-edge and 50mV falling-edge thresholds and 20mV hysteresis. When VCC drops below VBATT + 50mV, VOUT switches to VBATT; when VCC rises above VBATT + 70mV, VOUT returns to VCC. This ensures glitch-free handover and prevents oscillation near the crossover point. The MAX695CPE+ supports VBATT from 2.0V to 4.25V and draws only 1µA in battery mode.

Can the watchdog timeout period of the MAX695CPE+ be adjusted, and what are the available options?

Yes, the MAX695CPE+ watchdog timeout is adjustable via OSC SEL and OSC IN pins. With OSC SEL floating and OSC IN low, timeout is 100ms; with OSC SEL floating and OSC IN floating, it is 1.6s. With OSC SEL low, external clock or capacitor can set custom periods: e.g., 400ms/47pF × C or 1024 clock cycles. The MAX695CPE+ datasheet Table 1 confirms these configurations, and all modes retain the 200ms reset pulse width.

What is the function of the CE OUT pin on the MAX695CPE+, and how does it protect CMOS RAM?

The CE OUT pin on the MAX695CPE+ is a chip-enable gating output that follows CE IN when VCC > 4.65V but is forced high when VCC falls below that threshold-regardless of CE IN state. This blocks write access to CMOS RAM or EEPROM during power-up, brownout, or shutdown. With 50–200ns propagation delay and 3.0mA source capability, CE OUT directly drives RAM CE/CS pins, ensuring data integrity without external logic.

Does the MAX695CPE+ provide both active-low and active-high reset outputs, and how are they electrically related?

Yes, the MAX695CPE+ provides two complementary reset outputs: pin 11 (RESET, active-low) and pin 12 (RESET, active-high). They are internally inverted versions of the same signal-when pin 11 is low, pin 12 is high, and vice versa. Both outputs share the same 200ms timeout and respond identically to VCC drops, watchdog timeouts, or manual reset conditions. Each has independent 1.6mA sink and 1µA source capability, enabling direct interface to diverse microprocessor reset inputs.