Analog Devices Inc./Maxim Integrated MAX693CPE

Overview

MAX693CPE from Maxim Integrated is a 16-pin microprocessor supervisory circuit providing precision reset generation, battery backup switchover, adjustable watchdog timer, CMOS RAM write protection via CE gating, and power-fail detection. It features a 4.4V reset threshold, 50ms/200ms selectable reset timeout, 100ms/1.6s watchdog periods, 1.3V PFI comparator, and operates from -40°C to +85°C in plastic DIP package.

For engineers reviewing the MAX693CPE datasheet, MAX693CPE pinout, MAX693CPE application, or MAX693CPE equivalent, this page delivers verified functional identity, exact pin roles, real-world timing values, battery switchover hysteresis (70mV rise / 50mV fall), CE OUT propagation delay (50ns), and confirmed compatibility with 5V ±10% supplies.

Technical Context

The MAX693CPE integrates five core supervisory functions: (1) precision reset generation with 4.4V threshold and 40mV hysteresis; (2) dual-mode watchdog timer (100ms/1.6s internal or external-clock configurable); (3) battery switchover with 200Ω MOSFET and BATT ON output; (4) CE IN/CE OUT gating logic that forces CE OUT high when VCC drops below 4.4V; and (5) 1.3V PFI comparator with PFO output and automatic disable when VCC < VBATT.

It implements a dedicated low-power battery backup mode drawing ≤1µA at VCC = 0V, VBATT = 2.8V, and uses internal trimming for voltage accuracy. The RESET output is active-low with 3µA internal pullup, while WDO and LOW LINE provide independent fault signaling - all synchronized to the same timebase derived from either internal oscillator or external clock on OSC IN.

Key Specifications

Pinout & Package

MAX693CPE is housed in a 16-pin plastic DIP (Dual In-line Package) with 0.3-inch body width and through-hole mounting. Pin spacing is 0.1 inch, lead finish is tin-lead, and operating temperature range is -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 MAX693CPE, MAX693CSE+ offers identical functionality in surface-mount form but sacrifices mechanical reliability in high-vibration environments, while TPS3823MPW omits critical RAM protection and battery control features - making it unsuitable for systems requiring integrated CE gating or BATT ON-driven external pass transistors.

Availability

MAX693CPE is available at Aetrix Electronics and suitable for industrial controllers, automotive telematics modules, medical infusion pumps, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX693CPE 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 demanding industrial, automotive, and medical applications.

The MAX690–MAX695 family was engineered specifically for microprocessor system supervision - integrating reset, watchdog, battery switchover, CE gating, and power-fail detection into single 8- or 16-pin packages to eliminate discrete solutions and improve reliability.

FAQ

What is the guaranteed reset voltage threshold range for MAX693CPE?

The MAX693CPE has a guaranteed reset voltage threshold range of 4.25V to 4.5V, with a typical value of 4.4V. This specification is tested across the full operating temperature range (-40°C to +85°C) and ensures compatibility with 5V ±10% power supplies. The 40mV hysteresis prevents chatter during slow VCC transitions, and the threshold is trimmed at wafer level for accuracy - a key differentiator from discrete resistor-divider solutions.

Does MAX693CPE support adjustable watchdog timeout periods, and how is it configured?

Yes, MAX693CPE supports two watchdog timeout periods: 100ms and 1.6s. Configuration is achieved using the OSC SEL and OSC IN pins: when OSC SEL is floating and OSC IN is low, the 100ms period is active; when both are floating, the 1.6s period is selected. The timeout restarts on every WDI transition, and the timer is disabled if WDI is left floating - enabling flexible firmware supervision without hardware changes.

How does MAX693CPE protect CMOS RAM during power failure?

MAX693CPE protects CMOS RAM using its CE IN/CE OUT gating architecture. When VCC drops below 4.4V, CE OUT is forced high within 200ns - regardless of CE IN state - blocking write access to RAM. This action is synchronized with the LOW LINE output and occurs before RESET asserts, ensuring data integrity during brownouts. The feature eliminates need for external logic or microcontroller intervention.

What is the battery switchover behavior of MAX693CPE, and what is the dropout voltage?

MAX693CPE switches VOUT to VBATT when VCC falls 50mV below VBATT (power-down) and reverts to VCC when VCC rises 70mV above VBATT (power-up), with 20mV hysteresis. During battery backup, VOUT tracks VBATT minus a 20mV typical dropout (via 200Ω MOSFET), enabling efficient low-current operation. The BATT ON output drives external PNP transistors to boost VOUT current beyond 50mA if needed.

Can MAX693CPE monitor a backup battery voltage directly, and how is it implemented?

Yes, MAX693CPE can monitor backup battery voltage using the PFI input referenced to its internal 1.3V comparator. By connecting VBATT to PFI through a resistive divider, the device asserts PFO low when battery voltage drops below the programmed threshold - e.g., 2.6V for a 3V lithium cell. The PFI input draws only ±25nA, minimizing battery drain, and the comparator auto-disables when VCC < VBATT to prevent false warnings.