Analog Devices Inc./Maxim Integrated MAX706ARESA+

Overview

MAX706ARESA+ from Maxim Integrated is an active-low microprocessor supervisory circuit in 8-pin SO package, providing precision +3V supply monitoring (2.93V reset threshold), 200ms reset pulse width, watchdog timer (1.6s timeout), and power-fail comparator (1.25V reference). It ensures reliable µP reset during power-up, brownout, and power-down in battery-powered portable instruments.

For engineers reviewing the MAX706ARESA+ datasheet, MAX706ARESA+ pinout, MAX706ARESA+ application, or MAX706ARESA+ equivalent, this device supports critical voltage supervision with manual reset input, PFI/PFO monitoring, and guaranteed RESET assertion down to VCC = 1V - essential for embedded systems requiring deterministic startup and fault recovery.

Technical Context

The MAX706ARESA+ implements a dedicated reset generator with internal 200ms timer and hysteresis (20mV) on its 2.93V reset threshold detector. Its watchdog circuit monitors WDI transitions and asserts WDO low after 1.6s timeout unless refreshed; the watchdog is automatically disabled when WDI is left open or driven high-impedance (<600nA leakage).

It integrates a 1.25V precision reference for the PFI comparator, enabling external resistive-divider-based power-fail or low-battery detection. The active-low RESET output remains asserted for ≥200ms after VCC exceeds 2.93V or MR release, and is guaranteed functional down to VCC = 1V.

Key Specifications

Pinout & Package

MAX706ARESA+ is housed in an 8-pin SO (Small Outline) package (S8-2), surface-mount, lead-free compatible, with 1.27mm pitch and JEDEC MS-012AC outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706RCSA+, MAX706ARESA+ adds industrial temperature support and guaranteed VCC=1V operation; compared with TPS3808G12DBVR, it integrates watchdog and power-fail comparator at higher IQ, reducing BOM count and board area.

Availability

MAX706ARESA+ is available at Aetrix Electronics and suitable for battery-powered equipment, portable instruments, and industrial controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX706ARESA+ 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 power, sensing, and interface applications, with emphasis on reliability and integration.

The MAX706 family delivers cost-effective, single-chip µP supervision for +3V systems, targeting portable, industrial, and instrumentation markets where deterministic reset behavior and fault monitoring are critical.

FAQ

What is the reset threshold voltage of the MAX706ARESA+?

The MAX706ARESA+ has a nominal reset threshold voltage of 2.93V (VCC falling), with ±70mV tolerance over temperature. This value is factory-trimmed and specified in the Electrical Characteristics table under "Reset Threshold (VCC Falling)" for the 'S' suffix variant. The device guarantees RESET assertion until VCC rises above this threshold and holds it low for ≥200ms thereafter.

Does the MAX706ARESA+ include a watchdog timer?

Yes, the MAX706ARESA+ includes a watchdog timer with a nominal timeout period of 1.6 seconds. The timer resets on any edge transition at the WDI pin and asserts the WDO output low if no transition occurs within that window. Unlike the MAX706R/S/T variants, the MAX706ARESA+ ('AR' suffix) allows watchdog disable when WDI is left open or driven high-impedance with leakage <600nA.

Can the MAX706ARESA+ monitor voltages other than VCC?

Yes, the MAX706ARESA+ can monitor external voltages using its PFI (Power-Fail Input) pin, which compares the applied voltage against an internal 1.25V reference. By connecting PFI to a resistive divider from an unregulated supply or battery, users can generate early-warning PFO pulses before VCC drops, enabling orderly µP shutdown or data save operations.

What is the function of the MR pin on the MAX706ARESA+?

The MR (Manual Reset) pin on the MAX706ARESA+ is an active-low input that forces RESET assertion when pulled below 0.6V. It is TTL/CMOS-compatible, internally pulled up with a 70µA current source, and debounced by the 200ms reset timer. A momentary switch to GND or logic-low signal from a µP GPIO can trigger a controlled system reset without requiring external RC components.

Is the MAX706ARESA+ pin-compatible with other MAX706 variants?

Yes, the MAX706ARESA+ is pin-compatible with all 8-pin SO-packaged MAX706 variants (e.g., MAX706RCSA+, MAX706TESA+), sharing identical pinout, footprint, and electrical interface. Differences lie solely in reset threshold (2.63V/2.93V/3.08V), reset polarity (active-low only for 'R/S/T'), and temperature grade - allowing direct substitution where those parameters align with design requirements.