Analog Devices Inc./Maxim Integrated MAX1232EPA+

Overview

MAX1232EPA+ from Maxim Integrated is a microprocessor supervisory circuit that monitors +5V power 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 active-low reset outputs with ≥250ms pulse width and operates across –40°C to +85°C in an 8-pin PDIP package for embedded controller and instrumentation systems.

For engineers reviewing the MAX1232EPA+ datasheet, MAX1232EPA+ pinout, MAX1232EPA+ application, or MAX1232EPA+ equivalent, key selection criteria include its dual-reset output architecture, selectable 5%/10% VCC trip tolerance via TOL pin, no-external-components design, and guaranteed 250ms reset assertion during brownout, power-up, and manual reset events.

Technical Context

The MAX1232EPA+ integrates three core supervision functions: precision voltage monitoring (4.50–4.74V at 5% tolerance, 4.25–4.49V at 10%), a falling-edge-triggered watchdog timer with TD-pin-selectable timebases, and a debounced pushbutton reset input (PBRST) requiring ≥20ms low assertion to guarantee reset activation.

Its dual RST outputs serve complementary roles: RST sources/sinks current for direct µP reset, while RST is open-drain and requires external pull-up-enabling flexible interface with diverse logic families and voltage domains. All timing parameters-including tRST (250–1000ms), tPBD (1–20ms), and tTD (150/600/1200ms typ)-are specified over full temperature range and do not require calibration or trimming.

Key Specifications

Pinout & Package

MAX1232EPA+ is housed in an 8-pin plastic DIP (PDIP) package with 0.300" wide body and through-hole mounting. Pin spacing is 0.100", compatible with standard PCB layouts and socketing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UR29D3+ and TPS3808G33DBVR, the MAX1232EPA+ uniquely combines dual reset outputs, programmable watchdog timeout, debounced manual reset, and 5%/10% trip selection-all in one 8-pin PDIP device-making it optimal for µP systems requiring comprehensive, self-contained supervision without external timing or logic components.

Availability

MAX1232EPA+ is available at Aetrix Electronics and suitable for industrial controllers, test & measurement instruments, and embedded data loggers requiring stable component supply, extended temperature support, and long-term lifecycle continuity.

Supply support for MAX1232EPA+ 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 computing applications.

The MAX1232EPA+ belongs to Maxim's microprocessor supervisory product line, engineered specifically to replace legacy DS1232 devices with enhanced features including lower power, programmable watchdog, and dual-reset capability for robust embedded system reliability.

FAQ

What is the operating temperature range of the MAX1232EPA+?

The MAX1232EPA+ is rated for operation from –40°C to +85°C, making it suitable for industrial environments where ambient temperatures exceed commercial-grade limits. This rating is confirmed in the Absolute Maximum Ratings and Recommended DC Operating Conditions sections of the official datasheet, and applies to all electrical specifications unless otherwise noted. The MAX1232EPA+ maintains full functionality-including reset timing, voltage threshold accuracy, and watchdog timeout-across this full range without derating.

How does the MAX1232EPA+ implement its watchdog timer?

The MAX1232EPA+ watchdog timer is triggered by falling edges on the ST pin and times out if no edge occurs within the selected interval (150ms, 600ms, or 1.2s). The timeout is set by the TD pin: grounded for 150ms, floating for 600ms, or tied to VCC for 1.2s. Upon timeout, both RST and RST outputs assert for ≥250ms. The MAX1232EPA+ does not require external RC components-the timing is internally generated and factory-trimmed.

Can the MAX1232EPA+ be used as a direct replacement for the DS1232?

Yes, the MAX1232EPA+ is explicitly designed as a plug-in upgrade for the Dallas DS1232, sharing identical pinout, function mapping, and electrical compatibility in 8-pin PDIP packages. It consumes 1/10th the power, adds programmable watchdog timeout, and retains the same 250ms reset pulse width and 5%/10% trip selection. No PCB changes are required when replacing DS1232 with MAX1232EPA+.

What are the voltage trip thresholds for the MAX1232EPA+?

The MAX1232EPA+ offers two factory-set voltage trip thresholds: 4.50V–4.74V (typical 4.62V) for 5% tolerance when TOL = GND, and 4.25V–4.49V (typical 4.37V) for 10% tolerance when TOL = VCC. These ranges are guaranteed over temperature and supply variation, and the actual trip point is determined by internal precision bandgap references-not external resistors-ensuring stability and repeatability in the MAX1232EPA+.

Does the MAX1232EPA+ require external components for basic operation?

No, the MAX1232EPA+ requires no external components for core supervision functions: voltage monitoring, watchdog timing, and manual reset debouncing are fully integrated. A 0.1µF ceramic decoupling capacitor on VCC is recommended but not strictly required for functional operation per datasheet guidance. The MAX1232EPA+ eliminates the need for external RC networks, pull-up resistors on RST (though required for RST), or discrete debounce circuitry-reducing design complexity and bill-of-materials cost.