Analog Devices Inc./Maxim Integrated MAX6358LSUT

Overview

MAX6358LSUT from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with open-drain active-low reset output, 4.63V/2.93V precision factory-set VCC1/VCC2 thresholds, 46.4s watchdog startup timeout, and 2.9s normal watchdog timeout-designed for reliable power monitoring in multivoltage embedded systems such as industrial controllers and portable instrumentation.

For engineers reviewing the MAX6358LSUT datasheet, MAX6358LSUT pinout, MAX6358LSUT application, or MAX6358LSUT equivalent, key selection criteria include dual-supply threshold accuracy (±1.5% over temperature), guaranteed RESET validity down to VCC1 = 1.0V or VCC2 = 1.0V, 20µA quiescent current, and SOT23-6 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX6358LSUT implements independent voltage comparators for VCC1 and VCC2, asserting reset if either supply drops below its respective threshold (4.63V and 2.93V). Its watchdog timer operates in two distinct modes: a 46.4s startup timeout for system initialization and a 2.9s normal timeout for runtime processor activity monitoring.

Reset assertion is guaranteed as long as at least one supply remains ≥1.0V, and the open-drain RST output supports flexible pull-up configurations. The debounced manual-reset input (MR) provides deterministic reset initiation independent of supply state.

Key Specifications

Pinout & Package

MAX6358LSUT is housed in a 6-pin SOT23 package (U6-1 outline, 21-0058), with 1.27mm pitch, 2.8mm × 2.9mm footprint, and thermal pad not present. Pin 1 is RST (open-drain active-low reset), Pin 2 is GND, Pin 3 is MR (debounced manual-reset input), Pin 4 is VCC2, Pin 5 is WDI (watchdog 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 MAX6359LSUT, MAX6358LSUT offers greater interface flexibility via open-drain RST but requires an external pull-up; versus TPS3808G33DBVR, it delivers critical dual-rail supervision and watchdog capability essential for complex embedded systems-making it the only choice when both VCC1 and VCC2 must be monitored with processor activity assurance.

Availability

MAX6358LSUT is available at Aetrix Electronics and suitable for industrial controllers, portable medical instruments, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6358LSUT 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 semiconductor solutions for industrial, communications, computing, and consumer markets.

The MAX6351–MAX6360 family was engineered specifically for multivoltage microprocessor supervision-delivering precision dual-threshold detection, integrated watchdog timers, and ultra-low-power operation in minimal SOT23 footprints.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6358LSUT?

The MAX6358LSUT has factory-set reset thresholds of 4.63V for VCC1 and 2.93V for VCC2, each with ±1.5% tolerance over the full -40°C to +85°C operating range. These values are laser-trimmed during production and do not require external calibration. The "LS" suffix in MAX6358LSUT directly corresponds to this 4.63V/2.93V combination per Maxim's Voltage Threshold Levels table.

Does the MAX6358LSUT provide a watchdog timer, and what are its timeout periods?

Yes, the MAX6358LSUT includes a dual-mode watchdog timer with a 46.4s startup timeout period (to accommodate system boot sequences) and a 2.9s normal timeout period (for runtime processor activity monitoring). The timer resets on any valid edge (rising or falling) at the WDI pin and asserts RST if no edge occurs within the applicable timeout window. This behavior is confirmed in the Electrical Characteristics table on page 3 of the MAX6351–MAX6360 datasheet.

What type of reset output does the MAX6358LSUT feature, and how is it configured?

The MAX6358LSUT features an active-low open-drain reset output (RST) on Pin 1. It requires an external pull-up resistor to a valid logic rail (e.g., VCC1 or another system voltage). This configuration allows level translation and wired-OR connectivity with other reset sources. Unlike push-pull variants (e.g., MAX6359LSUT), the open-drain output cannot actively drive high, making it suitable for shared reset buses.

Can the MAX6358LSUT operate reliably when one supply drops below 1.0V?

No-the MAX6358LSUT guarantees valid reset output only as long as at least one supply (VCC1 or VCC2) remains ≥1.0V. Below that, internal circuitry may become nonfunctional and reset state is undefined. However, the device maintains correct RST assertion (low) down to 1.0V on either rail, enabling controlled shutdown sequencing in brownout scenarios. This specification is explicitly stated in the Absolute Maximum Ratings and Electrical Characteristics sections.

What is the supply current consumption of the MAX6358LSUT under typical operating conditions?

The MAX6358LSUT consumes 20µA typical supply current (ICC1 + ICC2) when VCC1 = 5.5V and VCC2 = 3.6V, with all I/O pins open. This ultra-low quiescent current is maintained across the full -40°C to +85°C temperature range and enables use in battery-powered and energy-harvesting applications where standby power is critical. Measured data appears in the Electrical Characteristics table on page 2 of the datasheet.