Analog Devices Inc./Maxim Integrated MAX6359TWUT+T

Overview

MAX6359TWUT+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with active-low push-pull reset referenced to VCC1, 3.08V VCC1 threshold, 1.67V VCC2 threshold, integrated watchdog timer (46.4s startup / 2.9s normal timeout), and 20µA supply current. It ensures reliable power-on reset and fault detection in multivoltage embedded systems.

For engineers reviewing the MAX6359TWUT+T datasheet, MAX6359TWUT+T pinout, MAX6359TWUT+T application, or MAX6359TWUT+T equivalent, key selection criteria include dual-supply monitoring thresholds, watchdog timing modes, reset output drive capability, operating temperature range (-40°C to +85°C), and SOT23-6 lead-free packaging compatibility.

Technical Context

The MAX6359TWUT+T implements independent precision voltage comparators for VCC1 and VCC2, asserting reset whenever either supply falls below its factory-trimmed threshold (3.08V / 1.67V). Its reset output remains valid as long as either VCC ≥ 1.0V, enabling robust brownout detection during power transitions.

It integrates a dual-mode watchdog timer: a 46.4s startup timeout allows full system initialization after power-up or manual reset, followed by a 2.9s normal timeout requiring periodic WDI edge transitions to prevent reset assertion - supporting both boot-critical and runtime supervision.

Key Specifications

Pinout & Package

MAX6359TWUT+T is housed in a RoHS-compliant, lead(Pb)-free 6-pin SOT23 package (U6-1 outline, 90-0175 land pattern), with 1.0mm pitch, 2.9mm × 1.6mm footprint, and thermal pad omitted.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-voltage supervisory applications.

Compared with MAX6359TWUT+T, the MAX6359TWUT-T offers identical performance in a non-RoHS package, while the TPS3808G30DBVR provides only single-rail supervision without watchdog - neither serves as a drop-in replacement, and both require design re-evaluation for dual-rail or watchdog-dependent systems.

Availability

MAX6359TWUT+T is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered IoT sensors, medical handheld diagnostics, and multivoltage industrial gateways requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6359TWUT+T 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, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6351–MAX6360 family delivers highly integrated, low-power supervisory circuits optimized for multivoltage embedded systems where reliability, small size, and guaranteed reset behavior across temperature and supply variations are critical.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6359TWUT+T?

The MAX6359TWUT+T has a factory-trimmed VCC1 threshold of 3.08V (±0.08V over -40°C to +85°C) and a VCC2 threshold of 1.67V (±0.05V over the same temperature range). These values are confirmed in the Voltage Threshold Levels table and Electrical Characteristics section of the official datasheet, and apply specifically to the "TW" suffix variant of the MAX6359TWUT+T.

Does the MAX6359TWUT+T provide an open-drain or push-pull reset output?

The MAX6359TWUT+T features an active-low push-pull reset output (RST) referenced to VCC1 - it actively drives low and high without requiring an external pull-up resistor. This is explicitly stated in the Pin Description and Detailed Description sections for the MAX6359 variant, distinguishing it from open-drain versions like the MAX6358.

How does the watchdog timer function on the MAX6359TWUT+T?

The MAX6359TWUT+T watchdog timer operates in two modes: a 46.4s startup timeout after power-up or reset, followed by a 2.9s normal timeout. A rising or falling edge on the WDI pin resets the timer; failure to update within the timeout period asserts RESET. This dual-mode architecture supports both boot initialization and runtime fault detection.

What is the minimum supply voltage required for the MAX6359TWUT+T to maintain a valid reset output?

The MAX6359TWUT+T guarantees valid RESET output as long as either VCC1 ≥ 1.0V or VCC2 ≥ 1.0V - a key reliability feature documented in the Absolute Maximum Ratings and Electrical Characteristics tables. This ensures fail-safe reset assertion even during deep brownout conditions on one supply rail.

Is the MAX6359TWUT+T RoHS-compliant and what package type does it use?

Yes, the MAX6359TWUT+T is RoHS-compliant and uses a lead(Pb)-free 6-pin SOT23 package (U6-1 outline). The "+T" suffix explicitly denotes lead-free packaging per Maxim's ordering nomenclature, and the device meets JEDEC J-STD-020 moisture sensitivity level 1 requirements.