Analog Devices Inc./Maxim Integrated MAX815TEPA+

Overview

MAX815TEPA+ from Maxim Integrated is a high-accuracy, low-power microprocessor supervisory circuit with integrated watchdog timer, power-fail monitor, and manual reset input. It provides active-low RESET output, 200ms reset timeout, ±1% reset threshold accuracy (3.03V), and guaranteed RESET validity down to VCC = 1V. It is used in portable/battery-powered equipment for reliable µP reset during brownout, power-up, and software fault conditions.

For engineers reviewing the MAX815TEPA+ datasheet, MAX815TEPA+ pinout, MAX815TEPA+ application, or MAX815TEPA+ equivalent, this page delivers verified functional identity, exact pin roles, confirmed 3.03V reset threshold behavior, watchdog timeout timing (1.56s), and real-world power-fail comparator operation at 1.70V - all specific to the MAX815TEPA+ variant.

Technical Context

The MAX815TEPA+ implements a dedicated watchdog timer with 1.56s timeout, independent of the reset comparator; it triggers WDO low on WDI inactivity (high or low state held >1.56s) and resets on any WDI transition. Its reset generator asserts active-low RESET for ≥200ms after VCC rises above 3.03V ±1%, with guaranteed logic-low output (≤0.4V) down to VCC = 1V.

Power-fail detection uses a 1.70V internal reference applied to PFI; when PFI falls below 1.70V, PFO sinks ≥1.2mA. The manual reset input (MR) features a 150µA internal pullup and triggers reset when pulled below 1.10V, with 200ms minimum pulse width after release.

Key Specifications

Pinout & Package

MAX815TEPA+ is housed in an 8-pin plastic DIP (PDIP) package with through-hole mounting and lead-free finish (+ suffix). Pin spacing is 0.300", body width 0.400", and standard JEDEC MS-001AC outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX815TEPA+, MAX814TEPA+ removes watchdog capability but adds low-line detection, while TPS3808G33DBVR trades feature richness for extreme current efficiency and smaller footprint - making each suitable for distinct subsystem requirements in power-critical embedded designs.

Availability

MAX815TEPA+ is available at Aetrix Electronics and suitable for medical equipment, portable/battery-powered equipment, intelligent instruments, critical µP power monitoring, and set-top boxes requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX815TEPA+ 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 and mixed-signal ICs for demanding industrial, medical, and communications applications, emphasizing reliability, accuracy, and low power.

The MAX814/MAX815/MAX816 family was engineered specifically for high-integrity microprocessor supervision in portable and critical systems - delivering ±1% reset accuracy, glitch-immune operation, and integrated watchdog/power-fail functions in minimal footprint.

FAQ

What is the exact reset threshold voltage of the MAX815TEPA+?

The MAX815TEPA+ has a factory-trimmed reset threshold of 3.03V ±1%, optimized for +3.3V supply systems. This value is fixed and non-adjustable - unlike the MAX816 series - and is confirmed in the Electrical Characteristics table for +3V parts under the MAX815T designation. The threshold remains stable across -40°C to +85°C and ensures reset assertion before most 3.3V µPs exit their valid operating range.

Does the MAX815TEPA+ include a watchdog timer, and what is its timeout period?

Yes, the MAX815TEPA+ integrates a dedicated watchdog timer with a nominal timeout period of 1.56 seconds. This timer monitors the WDI pin and triggers WDO low if WDI remains static (high or low) beyond that interval. The timeout is internally generated and independent of VCC or temperature variation, providing deterministic software fault detection essential for safety-critical firmware.

How does the power-fail monitoring function work on the MAX815TEPA+?

The MAX815TEPA+ uses a dedicated 1.70V internal reference to compare against the voltage applied to the PFI pin. When PFI falls below 1.70V, the PFO output pulls low (sinking ≥1.2mA), signaling impending supply failure. This allows connection to a µP interrupt or MR input to initiate controlled shutdown - a key capability distinguishing it from basic reset supervisors like the MAX809.

Can the MAX815TEPA+ operate with supply voltages below 3.0V?

Yes, the MAX815TEPA+ guarantees functional RESET output down to VCC = 1.0V, and its supply current remains stable (≤75µA) across 1.0V–5.5V. While the 3.03V reset threshold means it will assert RESET when VCC drops below that level, the device itself continues to monitor and drive outputs reliably even as VCC decays further - enabling graceful µP shutdown in deep brownout scenarios.

What package type and RoHS status does the MAX815TEPA+ have?

The MAX815TEPA+ is supplied in an 8-pin plastic DIP (PDIP) package with lead-free terminations, as indicated by the "+" suffix per Maxim's ordering convention. It complies with RoHS Directive 2011/65/EU and is rated for commercial temperature range (0°C to +70°C), though electrical specifications are guaranteed over -40°C to +85°C per the extended grade variants.