Analog Devices Inc./Maxim Integrated MAX1232EWE

Overview

MAX1232EWE from Maxim Integrated is a microprocessor supervisory circuit that monitors +5V supply voltage, provides debounced manual reset, and implements a digitally programmable watchdog timer with 150ms/600ms/1.2s timeout options. It delivers active-high and open-drain reset outputs, supports 5% or 10% VCC tolerance selection via TOL pin, and operates across –40°C to +85°C in a 16-pin wide SO package for industrial embedded systems requiring reliable power-on reset and software execution monitoring.

For engineers reviewing the MAX1232EWE datasheet, MAX1232EWE pinout, MAX1232EWE application, or MAX1232EWE equivalent, this page details its precision voltage detection (4.62V typical at 5% tolerance), 250ms minimum reset pulse width, low 50–200µA operating current, watchdog timebase configuration logic, and compatibility with legacy DS1232-based designs where extended temperature range and wide-SO layout are required.

Technical Context

The MAX1232EWE integrates three core supervision functions: a precision bandgap-based voltage detector with selectable 5% or 10% trip points (4.62V or 4.37V typ), a falling-edge-triggered watchdog timer whose timeout is set by TD pin voltage (GND = 150ms, open = 600ms, VCC = 1.2s), and a debounced pushbutton reset input (PBRST) that ignores <1ms glitches and guarantees recognition of ≥20ms pulses.

It features dual reset outputs - RST (active-high, push-pull) and RST (active-low, open-drain) - enabling flexible interface with diverse µP reset architectures. The device requires no external components, draws only 50–200µA supply current, and asserts reset during power-up, brownout, or watchdog timeout, holding outputs active for ≥250ms to ensure system stabilization.

Key Specifications

Pinout & Package

MAX1232EWE is housed in a 16-pin wide SO (SOIC-W) package with 0.300" body width and standard 0.050" pitch. Pin 1 is located at the top-left corner adjacent to the index mark; pins 1–8 occupy the top row, 9–16 the bottom row. No internal connections exist on pins 1, 3, 5, 7, 10, 12, 14, and 16.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX1232ESA and TPS3823-50DBVR, the MAX1232EWE uniquely combines industrial temperature rating, wide-SO mechanical robustness, dual reset polarity, and fully integrated watchdog/manual reset - making it optimal for complex µP systems needing comprehensive, self-contained supervision without layout compromises.

Availability

MAX1232EWE is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic equipment, telecom base station management, and automotive infotainment gateways requiring stable component supply, long-term lifecycle assurance, and guaranteed RoHS-compliant sourcing.

Supply support for MAX1232EWE 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 high-reliability semiconductor solutions for industrial, communications, and computing markets.

The MAX1232EWE belongs to Maxim's microprocessor supervisory product line, engineered specifically to replace legacy Dallas Semiconductor DS1232 devices while extending temperature range, improving power efficiency, and adding configurability for modern embedded systems.

FAQ

What is the operating temperature range of the MAX1232EWE?

The MAX1232EWE is rated for operation from –40°C to +85°C, making it suitable for industrial and extended-temperature applications where standard commercial-grade supervisors may fail. This range is confirmed in the Ordering Information table and Absolute Maximum Ratings section of the official datasheet. The MAX1232EWE maintains full specification compliance across this entire range without derating.

How does the MAX1232EWE configure its voltage detection threshold?

The MAX1232EWE selects its VCC trip point using the TOL pin: connecting TOL to GND sets a 5% tolerance (4.62V typical), while connecting TOL to VCC sets a 10% tolerance (4.37V typical). These thresholds are internally generated and do not require external resistors. The MAX1232EWE's voltage detector uses a precision bandgap reference to ensure stability across temperature and supply variations.

Does the MAX1232EWE support both active-high and active-low reset outputs?

Yes, the MAX1232EWE provides two independent reset outputs: RST (pin 9) is active-high with push-pull drive, and RST (pin 11) is active-low with open-drain output. This dual-output architecture allows direct interfacing with µPs requiring either polarity without external inverters or level shifters. Both outputs are asserted simultaneously during power-up, brownout, or watchdog timeout events.

What are the watchdog timeout options for the MAX1232EWE and how are they selected?

The MAX1232EWE offers three watchdog timeout periods: 150ms, 600ms, or 1.2s, selected by the voltage applied to the TD pin (pin 4). TD = GND yields 150ms, TD = open yields 600ms, and TD = VCC yields 1.2s. The timeout is measured from the last ST falling edge, and the MAX1232EWE forces reset if ST is not strobed within the selected interval - ensuring software execution integrity.

Is the MAX1232EWE a direct replacement for the DS1232?

The MAX1232EWE is described in its datasheet as a "plug-in upgrade" of the Dallas DS1232, sharing identical pinout, function set, and reset timing behavior. However, the MAX1232EWE adds lower power consumption (1/10th of DS1232), wider temperature range (–40°C to +85°C vs. 0°C to +70°C for DS1232C), and enhanced voltage tolerance selection. No PCB changes are required when upgrading from DS1232 to MAX1232EWE in compatible packages.