Analog Devices Inc./Maxim Integrated MAX6357UWUT

Overview

The MAX6357UWUT from Maxim Integrated is a triple-voltage microprocessor supervisory circuit with active-low push-pull reset output referenced to VCC2, factory-set VCC1 threshold of 2.78V and VCC2 threshold of 1.67V, 100ms minimum reset timeout, and support for third-voltage monitoring via RSTIN (1.22V threshold). It ensures system reliability in multivoltage embedded controllers by asserting reset when either supply drops below its trip point or when the external monitored voltage falls below the RSTIN comparator threshold.

For engineers reviewing the MAX6357UWUT datasheet, MAX6357UWUT pinout, MAX6357UWUT application, or MAX6357UWUT equivalent, key selection criteria include dual-supply reset assertion logic, guaranteed RESET validity down to VCC1 ≥ 1.0V or VCC2 ≥ 1.0V, 20µA quiescent current, 6-pin SOT23 package compatibility, and RSTIN-based third-voltage monitoring capability.

Technical Context

The MAX6357UWUT implements a dual-threshold voltage-monitoring architecture with independent VCC1 and VCC2 inputs, where reset is asserted if either supply falls below its factory-trimmed threshold (2.78V/1.67V). Its RSTIN pin provides a precision 1.22V reference for monitoring a third voltage via external resistive divider, enabling flexible undervoltage detection beyond the two primary rails.

It features an active-low push-pull RST2 output referenced to VCC2, debounced manual-reset input (MR), and operates across –40°C to +85°C with full electrical specifications guaranteed over temperature. The device draws only 20µA typical supply current and maintains valid reset output as long as either VCC1 or VCC2 remains ≥1.0V.

Key Specifications

Pinout & Package

MAX6357UWUT is housed in a 6-pin SOT23 package (U6-1 outline), surface-mount compatible with standard 0.95mm pitch footprint (land pattern 90-0175). The package supports reflow soldering and is available in both leaded and RoHS-compliant lead(Pb)-free variants (suffix +T).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6356UT-T and TPS3808G33DBVR, the MAX6357UWUT uniquely delivers VCC2-referenced push-pull reset output combined with guaranteed RSTIN-based third-voltage supervision down to 1.0V supply, making it the only option for systems requiring reset assertion timing aligned to a low-voltage domain while maintaining full brownout coverage.

Availability

MAX6357UWUT is available at Aetrix Electronics and suitable for industrial PLC controllers, medical handheld diagnostics, automotive body control modules, smart energy meters, and portable instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6357UWUT 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, communications, computing, and consumer applications, with emphasis on high-reliability, low-power, and integrated functionality.

The MAX6351–MAX6360 family was developed to replace discrete supervisory solutions in multivoltage embedded systems, delivering factory-trimmed accuracy, ultra-low quiescent current, and flexible reset architectures for space-constrained designs.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6357UWUT?

The MAX6357UWUT has a factory-set VCC1 threshold of 2.78V (±0.08V over –40°C to +85°C) and VCC2 threshold of 1.67V (±0.03V over temperature). These values are laser-trimmed during production and documented in the Electrical Characteristics table of the MAX6357UWUT datasheet under "VCC1 Threshold" and "VCC2 Threshold" parameters.

Does the MAX6357UWUT provide a third-voltage monitoring capability, and how is it implemented?

Yes, the MAX6357UWUT includes a dedicated RSTIN pin with a precision 1.22V internal reference (±0.03V) for monitoring a third voltage. An external resistive divider scales the target voltage to match this reference; for example, a 2.5V rail uses ~102kΩ/68kΩ resistors. The MAX6357UWUT asserts reset when the divided voltage falls below 1.22V, enabling flexible undervoltage detection beyond the two primary supplies.

What type of reset output does the MAX6357UWUT feature, and what is its reference domain?

The MAX6357UWUT features a single active-low push-pull reset output labeled RST2, which is explicitly referenced to VCC2. This means the output high level equals VCC2 and low level is near 0V, eliminating the need for an external pull-up resistor and ensuring deterministic timing relative to the secondary supply domain - a key distinction from VCC1-referenced variants like MAX6356UWUT.

How does the MAX6357UWUT maintain valid reset output during deep brownout conditions?

The MAX6357UWUT guarantees RESET output validity as long as either VCC1 ≥ 1.0V or VCC2 ≥ 1.0V, per Absolute Maximum Ratings and Electrical Characteristics. This is achieved through internal biasing that remains functional down to 1.0V on either rail, allowing the device to assert reset even during severe brownouts where conventional supervisors lose output control - a critical feature confirmed in the MAX6357UWUT datasheet's "Guaranteed RESET Valid to VCC1 = 1V or VCC2 = 1V" specification.

Is the MAX6357UWUT compatible with standard SOT23-6 PCB footprints, and what is its package code?

Yes, the MAX6357UWUT uses the industry-standard 6-pin SOT23 package (package code U6-1, outline 21-0058, land pattern 90-0175), fully compatible with common SOT23-6 footprints. It supports both leaded and RoHS-compliant lead(Pb)-free assembly (ordered with suffix +T), and its 0.95mm pin pitch and 2.9mm × 1.6mm body dimensions match JEDEC MO-178AB specifications verified in the MAX6357UWUT package drawing.