Analog Devices Inc./Maxim Integrated MAX706CPA+

Overview

The MAX706CPA+ from Maxim Integrated is a microprocessor supervisory circuit providing power-on reset, watchdog timeout detection, power-fail warning, and manual-reset functionality in a single 8-pin PDIP package. It asserts an active-low RESET output during power-up (VCC ≥ 1V), brownout (VCC < 4.40V), and manual trigger events, with guaranteed 200ms pulse width and valid operation down to VCC = 1V. It is used in embedded controllers and industrial instrumentation requiring reliable µP startup and fault recovery.

For engineers reviewing the MAX706CPA+ datasheet, MAX706CPA+ pinout, MAX706CPA+ application, or MAX706CPA+ equivalent, key selection criteria include its 4.40V reset threshold, 1.6s watchdog timeout, 1.25V PFI comparator reference, debounced MR input, and compatibility with +5V µP systems requiring fail-safe supervision without external components.

Technical Context

The MAX706CPA+ integrates a precision voltage monitor with 4.40V ±150mV reset threshold and 40mV hysteresis, a 1.6s watchdog timer with edge-sensitive WDI input (50ns minimum pulse width), and a dedicated 1.25V reference-based power-fail comparator driving open-drain PFO. Its RESET output remains low for ≥200ms after VCC rises above threshold or MR release, and stays asserted while VCC < 1V.

It features TTL/CMOS-compatible inputs (MR, WDI), guaranteed RESET validity at VCC = 1V, and operates across 1.0V to 5.5V supply range with typical supply current of 250µA. The device uses internal 250µA MR pull-up and supports pushbutton or logic-driven manual reset with 150ns MR-to-RESET delay.

Key Specifications

Pinout & Package

MAX706CPA+ is housed in an 8-pin plastic DIP (PDIP) package with 0.3-inch width, RoHS-compliant lead-free finish (indicated by '+' suffix), and standard through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706CPA+, MAX706CSA+ offers identical supervision functionality in a compact SO package ideal for high-density layouts, while MAX705CPA+ provides a higher reset threshold for systems with less stable +5V rails - neither is pin-compatible replacement without verifying reset timing impact on target µP.

Availability

MAX706CPA+ is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, telecom remote terminals, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX706CPA+ 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, computing, and communications markets.

The MAX705–MAX708 family was designed specifically for cost-sensitive microprocessor supervision in embedded systems, integrating reset, watchdog, power-fail, and manual-reset functions into minimal-footprint packages without sacrificing accuracy or reliability.

FAQ

What is the reset threshold voltage for MAX706CPA+?

The MAX706CPA+ has a nominal reset threshold of 4.40V with ±150mV tolerance, meaning it asserts the active-low RESET output whenever VCC drops below approximately 4.25V. This threshold is factory-trimmed and guaranteed over temperature and supply variations. The MAX706CPA+ uses this specific value to match common +5V regulator tolerances and provide earlier reset than the 4.65V MAX705 variant.

Does MAX706CPA+ support watchdog functionality?

Yes, the MAX706CPA+ includes a fully functional watchdog timer with 1.6s nominal timeout period. It monitors the WDI pin for rising or falling edges; if no edge occurs within 1.6s, WDO goes low. The timer clears automatically on RESET assertion, WDI three-state, or any WDI transition. This enables robust µP lockup detection in safety-critical applications.

Can MAX706CPA+ monitor voltages other than +5V?

Yes, the MAX706CPA+ can monitor any DC voltage using its PFI input and internal 1.25V reference. By connecting a resistor divider from the target voltage to PFI, users scale the monitored voltage so that it crosses 1.25V at the desired trip point - e.g., a 12V rail can be monitored for drop below 11V. The PFI input draws only ±25nA, minimizing loading error.

What is the minimum supply voltage at which MAX706CPA+ guarantees RESET output validity?

The MAX706CPA+ guarantees valid RESET output down to VCC = 1.0V. At this level, RESET remains a logic-low output (≤0.4V) with sink capability, ensuring the connected µP stays held in reset even during severe brownout conditions. This specification is tested and guaranteed across the full 0°C to +70°C operating range.

Is MAX706CPA+ RoHS-compliant and lead-free?

Yes, the '+' suffix in MAX706CPA+ explicitly denotes RoHS-compliant, lead-free packaging per JEDEC J-STD-609. It uses matte tin plating on leads and meets EU Directive 2011/65/EU requirements. The device is qualified for reflow soldering at +260°C peak temperature and is suitable for modern environmentally regulated production environments.