Analog Devices Inc./Maxim Integrated MAX6355RWUT-T

Overview

The MAX6355RWUT-T from Maxim Integrated is a triple-voltage microprocessor supervisory circuit with active-low open-drain reset output, 2.63V/1.67V dual supply thresholds, and RSTIN input for monitoring a third voltage at 1.22V. It operates over -40°C to +85°C in a 6-pin SOT23 package and supports systems requiring guaranteed RESET validity down to VCC1 = 1V or VCC2 = 1V. Used in multivoltage embedded controllers where precise undervoltage detection across three rails is critical.

For engineers reviewing the MAX6355RWUT-T datasheet, MAX6355RWUT-T pinout, MAX6355RWUT-T application, or MAX6355RWUT-T equivalent, key selection criteria include its open-drain RST output, factory-trimmed VTH1/VTH2 thresholds (2.63V/1.67V), RSTIN comparator input for external voltage scaling, 20µA quiescent current, and guaranteed operation with either supply ≥1.0V - essential for battery-backed or low-voltage rail supervision.

Technical Context

The MAX6355RWUT-T implements a dual-threshold voltage monitor with independent trip points on VCC1 (2.63V) and VCC2 (1.67V), asserting reset if either supply falls below its threshold. Its RSTIN pin accepts an externally scaled voltage referenced to VCC1 and compares it against a precision 1.22V internal reference with ±6mV tolerance over temperature.

Reset assertion is latched until both supplies recover above their thresholds and the reset timeout period (100–280ms) elapses. The open-drain RST output requires an external pull-up and remains valid as long as VCC1 ≥1.0V or VCC2 ≥1.0V, enabling reliable reset generation during brownout conditions.

Key Specifications

Pinout & Package

MAX6355RWUT-T is housed in a 6-pin SOT23 package (U6-1 outline, land pattern 90-0175), with pin 1 marked by a dot or bevelled edge. The device uses BiCMOS process technology and supports lead(Pb)-free ordering (replace "-T" with "+T").

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6356RWUT-T, the MAX6355RWUT-T provides open-drain flexibility for multi-device reset arbitration; compared with TPS3808G33DBVR, it delivers true triple-rail supervision with scalable RSTIN input - making it indispensable for multivoltage systems where coordinated reset across domains is mandatory.

Availability

MAX6355RWUT-T is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered data loggers, medical handheld diagnostics, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6355RWUT-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, medical, communications, and computing applications.

The MAX6351–MAX6360 family was engineered specifically for multivoltage microprocessor systems requiring coordinated reset across two or three independent supply rails with minimal external components.

FAQ

What is the function of the RSTIN pin on the MAX6355RWUT-T?

The RSTIN pin on the MAX6355RWUT-T is an adjustable reset comparator input referenced to VCC1, with a precision internal threshold of 1.22V ±0.03V. It allows monitoring of a third voltage rail (e.g., 3.3V or 5V) using an external resistive divider. When the scaled voltage at RSTIN falls below 1.22V, the MAX6355RWUT-T asserts its open-drain RST output. This feature eliminates the need for additional supervisor ICs in triple-rail systems.

Does the MAX6355RWUT-T support operation when only one supply is present?

Yes, the MAX6355RWUT-T guarantees valid reset output as long as either VCC1 ≥ 1.0V or VCC2 ≥ 1.0V - even if the other supply is absent or at 0V. This behavior is explicitly specified in the Electrical Characteristics table and enables robust reset generation during asymmetric power-up/down sequences or partial supply failure, a key requirement in fault-tolerant embedded systems using the MAX6355RWUT-T.

What are the exact voltage thresholds for the MAX6355RWUT-T?

The MAX6355RWUT-T has factory-trimmed thresholds of 2.63V ±0.05V on VCC1 and 1.67V ±0.03V on VCC2 at +25°C, with temperature drift limited to 20ppm/°C. These values are confirmed in the Voltage Threshold Levels table and Electrical Characteristics section of the datasheet. The RSTIN input threshold is 1.22V ±0.03V, independent of supply voltage variations - all parameters are production-tested and guaranteed over -40°C to +85°C.

Can the MAX6355RWUT-T replace a MAX6352 or MAX6358 in an existing design?

No - the MAX6355RWUT-T is not a drop-in replacement for MAX6352 or MAX6358. While all three share the 6-pin SOT23 package and open-drain RST output, MAX6355RWUT-T includes the RSTIN input for third-voltage monitoring (absent in MAX6352/MAX6358) and lacks the watchdog timer found in MAX6358. Pin 5 is RSTIN on MAX6355RWUT-T but WDI on MAX6358, making direct substitution electrically incompatible without board revision.

What is the minimum recommended pull-up resistor value for the RST output of the MAX6355RWUT-T?

The MAX6355RWUT-T's open-drain RST output is specified to sink 1.2mA at VOL ≤ 0.3V when VCC1 or VCC2 ≥ 2.7V. To ensure proper logic-low assertion under worst-case conditions, a pull-up resistor ≤ 10kΩ to the target logic rail (e.g., 3.3V) is recommended. Lower values (e.g., 4.7kΩ) improve noise immunity and rise time; higher values may risk marginal VOL in high-temperature or high-capacitance environments. This design guidance applies specifically to the MAX6355RWUT-T's RST pin configuration.