Analog Devices Inc./Maxim Integrated MAX706EUA

Overview

The MAX706EUA from Maxim Integrated is a precision microprocessor supervisory circuit in an 8-pin µMAX package, providing active-low reset output, 1.6s watchdog timer, 4.40V supply-voltage monitoring threshold, 1.25V power-fail comparator input, and debounced manual-reset input - used to ensure reliable boot-up and brownout recovery in embedded controllers and industrial instrumentation.

For engineers reviewing the MAX706EUA datasheet, MAX706EUA pinout, MAX706EUA application, or MAX706EUA equivalent, this device supports critical μP power monitoring with guaranteed RESET validity down to VCC = 1V, 200ms reset pulse width, and TTL/CMOS-compatible manual-reset interface - key for robust system initialization and fault recovery design.

Technical Context

The MAX706EUA integrates four core supervisory functions: a precision voltage monitor triggering reset below 4.40V (±15mV typical hysteresis), a watchdog timer with 1.6s timeout (±0.6s tolerance) cleared on WDI edge transitions, a 1.25V reference-based power-fail comparator (PFI/PFO), and a 250μA-pullup MR input with 150ns minimum pulse width support.

Its internal timebase ensures synchronized reset assertion during power-up (valid at VCC ≥ 1V), brownout (RESET held low until VCC rises >4.40V + hysteresis), and manual trigger events - while WDO operates independently as a low-line indicator when VCC drops below threshold, without fixed pulse-width guarantee.

Key Specifications

Pinout & Package

MAX706EUA is housed in an 8-pin µMAX package (2.1mm × 2.3mm, 0.5mm pitch), RoHS-compliant, with exposed pad for thermal enhancement. Pin numbering follows standard top-view orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706CSA and MAX706CUA, the MAX706EUA offers extended -40°C to +85°C operation in the same compact µMAX package - essential for reliability in harsh environments without sacrificing board space or thermal performance.

Availability

MAX706EUA is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX706EUA 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 high-performance analog and mixed-signal ICs for power, sensing, and connectivity applications - emphasizing reliability, integration, and ruggedness in harsh environments.

The MAX705–MAX708 family delivers cost-effective, single-chip μP supervision targeting embedded systems needing guaranteed reset behavior, watchdog safety, and multi-rail monitoring - with MAX706EUA optimized for 4.40V threshold and extended temperature operation.

FAQ

What is the reset threshold voltage of the MAX706EUA?

The MAX706EUA has a nominal reset threshold of 4.40V, with a guaranteed range of 4.25V to 4.50V over the full -40°C to +85°C operating temperature range. This threshold is specifically selected for systems using +5V regulators with tighter dropout margins than the 4.65V variant (MAX705), ensuring earlier reset assertion during brownout conditions. The MAX706EUA maintains this specification consistently across its entire temperature range.

Does the MAX706EUA provide both active-high and active-low reset outputs?

No, the MAX706EUA provides only an active-low RESET output. It does not include the active-high RESET output found in the MAX707/MAX708 series. The MAX706EUA belongs to the MAX705/MAX706/MAX813L group, which features RESET (active-low) and WDO (watchdog output), but no complementary active-high reset signal. For dual-output capability, consider MAX707EUA or MAX708EUA instead.

Can the MAX706EUA monitor voltages other than +5V?

Yes, the MAX706EUA can monitor any DC voltage using its PFI (Power-Fail Input) pin, which compares against an internal 1.25V reference. By connecting a resistor divider from the target voltage rail to PFI, users can configure detection thresholds for +12V, +3.3V, or even negative supplies. The MAX706EUA datasheet includes application circuits for monitoring both positive and negative rails, confirming this capability is fully supported and characterized.

What is the minimum supply voltage at which MAX706EUA guarantees RESET output validity?

The MAX706EUA guarantees valid RESET output down to VCC = 1.0V, as specified in its Electrical Characteristics table under "Operating Voltage Range" and confirmed in the Detailed Description section. At VCC = 1.0V, RESET remains a guaranteed logic low (≤0.3V with 50μA sink current), enabling safe microprocessor hold states during deep brownout - a key differentiator versus many competing supervisors that require ≥2.0V for reset functionality.

How does the watchdog timer in MAX706EUA clear and respond to input transitions?

The MAX706EUA watchdog timer clears on any rising or falling edge at the WDI pin - not on level changes - and also resets automatically whenever RESET is asserted or WDI is three-stated. The timer has a nominal 1.6s timeout (1.00s to 2.25s range), and detects pulses as short as 50ns. This edge-triggered clearing mechanism prevents false timeouts during debug sessions or low-power sleep modes where WDI may be held static, enhancing system robustness in real-world firmware implementations.