Analog Devices Inc./Maxim Integrated MAX6359SVUT

Overview

MAX6359SVUT from Maxim Integrated is a dual-voltage microprocessor supervisory IC with active-low push-pull reset referenced to VCC1, factory-set VCC1 threshold of 2.93V and VCC2 threshold of 1.58V, 20µA supply current, 100ms min reset pulse width, and integrated watchdog timer (46.4s startup / 2.9s normal timeout). It ensures reliable power-on reset and fault detection in multivoltage embedded systems.

For engineers reviewing the MAX6359SVUT datasheet, MAX6359SVUT pinout, MAX6359SVUT application, or MAX6359SVUT equivalent, key selection criteria include dual-supply monitoring capability, guaranteed RESET validity down to VCC1 = 1V or VCC2 = 1V, watchdog timer timing parameters, SOT23-6 package compatibility, and voltage threshold accuracy over -40°C to +85°C.

Technical Context

The MAX6359SVUT implements independent precision voltage comparators for VCC1 and VCC2, asserting reset when either supply drops below its respective factory-trimmed threshold (2.93V/1.58V). Its reset output is push-pull referenced to VCC1, eliminating external pull-up requirements.

It integrates a dual-mode watchdog timer with 46.4s startup timeout (for system initialization) and 2.9s normal timeout (for runtime supervision), triggered by WDI edge transitions. The device guarantees functional operation as long as either VCC1 ≥ 1.0V or VCC2 ≥ 1.0V, enabling robust low-voltage reset assertion.

Key Specifications

Pinout & Package

MAX6359SVUT is housed in a 6-pin SOT23 package (JEDEC MO-178AA), with 1.3mm × 2.9mm body size, 0.95mm height, and 0.95mm pitch. Pin 1 is RST (active-low push-pull reset referenced to VCC1), Pin 2 is GND, Pin 3 is MR (debounced manual reset input), Pin 4 is VCC2, Pin 5 is WDI (watchdog timer input), and Pin 6 is VCC1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6359SVUT, MAX6360SVUT provides identical dual-threshold monitoring but shifts reset assertion to the VCC2 domain - useful for mixed-voltage logic interfacing - while TPS3808G33DBVR offers lower cost and smaller footprint but sacrifices dual-supply capability and watchdog supervision entirely.

Availability

MAX6359SVUT is available at Aetrix Electronics and suitable for industrial PLC controllers, medical handheld diagnostics, automotive body control modules, and industrial IoT edge gateways requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6359SVUT 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 industrial, automotive, communications, and computing applications.

The MAX6351–MAX6360 family was engineered specifically for multivoltage microprocessor systems requiring simultaneous monitoring of two independent supply rails with integrated watchdog supervision and guaranteed low-voltage reset functionality.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6359SVUT?

The MAX6359SVUT has a factory-trimmed VCC1 threshold of 2.93V (±0.05V at +25°C) and a VCC2 threshold of 1.58V (±0.03V at +25°C), as defined by the "SV" suffix in the part number and confirmed in the Voltage Threshold Levels table of the datasheet. These values are guaranteed over the full -40°C to +85°C operating range.

Does the MAX6359SVUT require external pull-up resistors on its RST output?

No, the MAX6359SVUT features an active-low push-pull RST output referenced to VCC1, meaning it actively drives both high and low states without needing external pull-up components. This simplifies design, reduces BOM count, and ensures fast, deterministic reset signaling in systems where VCC1 powers the reset-receiving logic.

How does the watchdog timer on the MAX6359SVUT operate during system startup?

The MAX6359SVUT watchdog timer initiates a 46.4s startup timeout period after any reset event (power-on, manual, or watchdog-triggered). This extended window allows complex firmware initialization before watchdog enforcement begins. Once the first valid WDI edge occurs or the 46.4s expires, the timer switches to 2.9s normal timeout mode for ongoing supervision.

Can the MAX6359SVUT maintain valid reset output if one supply rail drops to 1.0V?

Yes, the MAX6359SVUT guarantees RESET output validity as long as either VCC1 ≥ 1.0V or VCC2 ≥ 1.0V - a key feature documented in the Electrical Characteristics table. This ensures reliable brownout detection and controlled shutdown even during severe undervoltage conditions on one rail.

What package type and pin count does the MAX6359SVUT use?

The MAX6359SVUT uses a 6-pin SOT23 package (JEDEC MO-178AA), with standardized pinout: Pin 1 = RST (push-pull), Pin 2 = GND, Pin 3 = MR, Pin 4 = VCC2, Pin 5 = WDI, Pin 6 = VCC1. This compact surface-mount package supports high-density PCB layouts and automated assembly.