Analog Devices Inc./Maxim Integrated MAX813LESA

Overview

The MAX813LESA from Maxim Integrated is a precision microprocessor supervisory circuit providing active-high reset output, watchdog timer, power-fail warning, and manual-reset input in an 8-pin SO package. It asserts RESET when VCC drops below 4.65V, delivers a guaranteed 200ms reset pulse width, monitors PFI at 1.25V threshold, and features watchdog timeout of 1.6s - all operating down to VCC = 1.2V. It is used in industrial controllers and embedded systems requiring reliable power-up sequencing and brownout recovery.

For engineers reviewing the MAX813LESA datasheet, MAX813LESA pinout, MAX813LESA application, or MAX813LESA equivalent, this page provides verified functional specifications, validated pin roles, confirmed temperature range (–40°C to +85°C), SO-package mechanical data, and two field-validated alternative parts with documented technical and application differences.

Technical Context

The MAX813LESA integrates four core supervisory functions: a precision voltage monitor with 4.65V reset threshold and 40mV hysteresis, a 1.6s watchdog timer that clears on WDI edge transitions or RESET assertion, a 1.25V power-fail comparator with nanosecond-level response, and a debounced TTL/CMOS-compatible manual-reset input with internal 250µA pull-up.

Its active-high RESET output remains valid down to VCC = 1.2V (ISOURCE = 4µA), while WDO and PFO are open-drain outputs capable of sinking 3.2mA and 1.2mA respectively. All timing and threshold parameters are specified across –40°C to +85°C and guaranteed over supply voltage range 1.2V to 5.5V.

Key Specifications

Pinout & Package

MAX813LESA is housed in an 8-pin Small Outline (SO) package, 3.9mm × 4.9mm body, 1.27mm pitch, RoHS-compliant with lead-free finish (suffix "+" implied per ordering convention).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX813LESA, MAX706ESA offers lower reset threshold and inverted output but omits active-high RESET and reduces feature set, while MAX809SEUR+T sacrifices all supervision functions for minimal footprint and cost - making MAX813LESA the only option supporting full four-function supervision in SO-8 at industrial temperature.

Availability

MAX813LESA is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic equipment, automotive infotainment head units, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX813LESA 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 industrial, communications, and computing applications, emphasizing reliability, integration, and performance under harsh conditions.

The MAX705–MAX708/MAX813L family was engineered to replace discrete reset and watchdog circuits in microprocessor-based systems, delivering guaranteed timing, low-voltage operation, and multi-function integration in compact packages.

FAQ

What is the reset threshold voltage of the MAX813LESA?

The MAX813LESA has a nominal reset threshold of 4.65V with ±1.5% tolerance over temperature and supply. This value is guaranteed across its full operating range (–40°C to +85°C, VCC = 1.2V to 5.5V). The device asserts its active-high RESET output when VCC falls below this threshold and holds it low for at least 200ms after VCC rises above the threshold. The MAX813LESA uses this fixed 4.65V level - unlike variants such as MAX706 which use 4.40V.

Does the MAX813LESA provide both active-high and active-low reset outputs?

No, the MAX813LESA provides only an active-high RESET output (pin 7). It does not include an active-low RESET output. This distinguishes it from the MAX707/MAX708 series, which offer both polarities. The MAX813LESA's RESET output is push-pull, valid down to VCC = 1.2V, and remains high during normal operation - going low only during reset assertion triggered by power failure, manual reset, or watchdog timeout.

What is the watchdog timeout period for the MAX813LESA?

The MAX813LESA features a watchdog timer with a nominal timeout period of 1.6 seconds, with ±40% variation over temperature and supply voltage. The timer resets on any rising or falling edge at the WDI pin (pin 8), and is also cleared automatically when RESET is asserted or when WDI is three-stated. The WDO output (pin 6) goes low upon timeout and remains low until cleared - making it suitable for NMI triggering or low-line indication.

Can the MAX813LESA monitor voltages other than the main VCC supply?

Yes, the MAX813LESA can monitor external voltages using its PFI (Power-Fail Input) pin (pin 4), which compares against an internal 1.25V reference. By connecting a resistor divider from the target voltage to PFI, users can configure monitoring of 3.3V, 2.5V, battery rails, or negative supplies. The PFO output (pin 5) then signals violations. This capability is explicitly supported in the MAX813LESA datasheet and requires no additional components beyond the divider network.

What package type and RoHS status does the MAX813LESA use?

The MAX813LESA is supplied in an 8-pin Small Outline (SO) package, 3.9mm × 4.9mm body size, 1.27mm lead pitch. It is RoHS-compliant and lead-free, conforming to JEDEC MS-012 standards. Per Maxim's ordering convention, the "+" suffix denotes lead-free packaging - though it is omitted in the base part number MAX813LESA, the device shipped meets RoHS requirements and is compatible with standard reflow profiles (peak 260°C).