Analog Devices Inc./Maxim Integrated MAX706CSA+

Overview

The MAX706CSA+ from Maxim Integrated is a low-cost microprocessor supervisory circuit providing power-on reset, watchdog timer, power-fail warning, and manual-reset functions for +5V systems. It asserts an active-low RESET output during power-up (valid down to VCC = 1V), brownout (below 4.40V threshold), and manual trigger; features a 1.6s watchdog timeout; and monitors auxiliary supplies via 1.25V PFI comparator. It is widely used in embedded controllers and industrial instrumentation requiring reliable, single-chip power monitoring.

For engineers reviewing the MAX706CSA+ datasheet, MAX706CSA+ pinout, MAX706CSA+ application, or MAX706CSA+ equivalent, this page delivers verified technical context, exact pin functions, real-world use cases, and validated alternative parts - all grounded in Maxim's official specifications for the SO-8 package, commercial temperature grade, and lead-free + suffix variant.

Technical Context

The MAX706CSA+ integrates four core supervisory functions on a single die: a precision voltage monitor with 4.40V ±150mV reset threshold and 40mV hysteresis; a watchdog timer that triggers WDO low if WDI remains static beyond 1.6s (±0.65s); a 1.25V ±50mV power-fail comparator with <400ns assertion/deassertion response; and a debounced TTL/CMOS-compatible MR input with 250µA internal pull-up and 150ns minimum pulse width.

Its RESET output guarantees logic-low state (≤0.4V at 3.2mA sink) for ≥140ms after VCC rises above threshold or MR release, and remains asserted while VCC < 1V. The device operates from 1.0V to 5.5V supply, draws only 150–350µA quiescent current, and maintains functional integrity across 0°C to +70°C ambient.

Key Specifications

Pinout & Package

MAX706CSA+ is housed in an 8-pin SO (Small Outline) package, RoHS-compliant and lead-free, with standard 1.27mm pitch and JEDEC MS-012AC outline. Pin 1 is marked by a beveled corner or dot; pin numbering follows counterclockwise convention from pin 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706CSA+, MAX706ESA+ extends thermal range without changing footprint or function, while MAX813LCSA+ trades watchdog independence for dual-reset polarity - making MAX706CSA+ optimal for cost-sensitive, temperature-stable designs needing both reset and watchdog outputs.

Availability

MAX706CSA+ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, network router management cards, and automotive infotainment head units requiring stable component supply and long-term manufacturability.

Supply support for MAX706CSA+ 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, communications, and computing markets.

The MAX705–MAX708 family was designed specifically for cost-sensitive microprocessor systems needing integrated reset, watchdog, and power-fail monitoring - delivering reliability without complexity or external components.

FAQ

What is the reset threshold voltage for MAX706CSA+?

The MAX706CSA+ has a nominal reset threshold of 4.40V with a tolerance of ±150mV, meaning RESET asserts when VCC falls below 4.25V and releases when VCC rises above 4.50V. This threshold is factory-trimmed and guaranteed over the 0°C to +70°C temperature range. The 40mV hysteresis prevents chatter near the trip point. This value distinguishes MAX706CSA+ from the 4.65V-threshold MAX705CSA+ and is explicitly confirmed in Maxim's Electrical Characteristics table.

Does MAX706CSA+ provide both active-low and active-high reset outputs?

No, MAX706CSA+ provides only an active-low RESET output (pin 7) and an open-drain active-low WDO output (pin 8). It does not include the active-high RESET output found on MAX707/MAX708/MAX813L variants. The MAX706CSA+ datasheet clearly states it belongs to the MAX705/MAX706 subgroup, which omits the complementary reset signal. For dual-polarity reset, MAX813LCSA+ is the appropriate alternative.

Can MAX706CSA+ monitor a 3.3V supply for power-fail detection?

Yes, MAX706CSA+ can monitor a 3.3V supply using its PFI input. Connect PFI to a resistive divider from the 3.3V rail such that the voltage at PFI equals 1.25V when the supply reaches the desired warning threshold (e.g., 3.0V). The internal 1.25V comparator then triggers PFO low. The PFI input draws only ±25nA, minimizing loading error, and the comparator's 400ns response time ensures timely warning before system failure.

What is the watchdog timeout period for MAX706CSA+?

The MAX706CSA+ watchdog timeout period is 1.6 seconds typical, with a guaranteed range of 1.00s to 2.25s over temperature and supply voltage. This is measured from the last edge on WDI (pin 6); if no rising or falling edge occurs within that window, WDO (pin 8) pulls low. The timeout is independent of VCC as long as it remains above 1.0V, and resets automatically on any WDI edge, RESET assertion, or WDI three-state.

Is MAX706CSA+ compatible with 3.3V microcontrollers?

MAX706CSA+ is designed for +5V systems but interfaces reliably with 3.3V µCs. Its RESET and WDO outputs are CMOS/TTL-compatible: RESET drives low to ≤0.4V (sinking 3.2mA), safely below 3.3V logic low thresholds, and WDO's open-drain structure allows pull-up to 3.3V. MR input accepts 0.8V/2.0V TTL thresholds, and PFI operates independently of VCC logic levels - all confirmed in the Absolute Maximum Ratings and Electrical Characteristics sections.