Analog Devices Inc./Maxim Integrated MAX6355LTUT

Overview

MAX6355LTUT from Maxim Integrated is a triple-voltage microprocessor supervisory circuit with open-drain active-low reset output, monitoring VCC1 (4.63V threshold), VCC2 (3.08V threshold), and a third voltage via RSTIN (1.22V fixed comparator input). It operates from -40°C to +85°C in a 6-pin SOT23 package and supports systems requiring reliable power-up sequencing and undervoltage detection across three rails.

For engineers reviewing the MAX6355LTUT datasheet, MAX6355LTUT pinout, MAX6355LTUT application, or MAX6355LTUT equivalent, key selection criteria include its dual-supply monitoring capability, RSTIN-based third-voltage supervision, open-drain reset architecture, and guaranteed operation down to VCC1 ≥ 1.0V or VCC2 ≥ 1.0V - critical for battery-backed and multirail embedded control designs.

Technical Context

The MAX6355LTUT integrates two independent precision voltage comparators for VCC1 and VCC2, plus a dedicated 1.22V reference comparator on RSTIN for external resistive-divider-based third-rail monitoring. Its reset assertion logic triggers if any monitored supply falls below its factory-set threshold, with hysteresis of VTH/500 and tempco of 20ppm/°C.

It features a debounced TTL/CMOS-compatible manual-reset input (MR), guarantees RESET validity as long as either VCC1 or VCC2 exceeds +1.0V, and provides 100ms minimum power-on-reset pulse width. Unlike MAX6358–MAX6360 variants, it excludes watchdog timer functionality.

Key Specifications

Pinout & Package

MAX6355LTUT is housed in a 6-pin SOT23 package (U6-1 outline, land pattern 90-0175), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and 1.1mm max height - compatible with standard high-density PCB assembly processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6356LTUT, MAX6355LTUT offers open-drain flexibility for multi-drop reset busing, while TPS3808G33DBVR lacks RSTIN entirely - making MAX6355LTUT the only drop-in option for designs requiring factory-trimmed triple-rail supervision in 6-pin SOT23.

Availability

MAX6355LTUT is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical diagnostics, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature and multivoltage operating conditions.

Supply support for MAX6355LTUT 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for industrial, communications, and computing applications.

The MAX6351–MAX6360 family was designed to replace discrete supervisor solutions in multivoltage embedded systems - delivering precision, low power, and compact packaging for reliable power-up, brownout, and reset management.

FAQ

What is the function of the RSTIN pin on the MAX6355LTUT?

The RSTIN pin on the MAX6355LTUT is a dedicated third-voltage comparator input with a fixed 1.22V internal reference. When an external voltage applied to RSTIN falls below this threshold, the device asserts its open-drain RST output. To monitor voltages higher than 1.22V, a resistive divider must be used between the target rail and RSTIN, referenced to GND. The MAX6355LTUT datasheet specifies RSTIN is powered by VCC1 and must not exceed VCC1.

Does the MAX6355LTUT include a watchdog timer?

No, the MAX6355LTUT does not include a watchdog timer. Watchdog functionality is exclusive to the MAX6358, MAX6359, and MAX6360 variants in the same family. The MAX6355LTUT provides triple-voltage supervision (VCC1, VCC2, and RSTIN) with manual reset and open-drain reset output, but no WDI pin or timeout logic. This makes it suitable for applications where system-level watchdog supervision is handled externally or not required.

What are the exact voltage thresholds for MAX6355LTUT?

The MAX6355LTUT has factory-set thresholds of 4.63V for VCC1 (with ±0.09V tolerance over -40°C to +85°C) and 3.08V for VCC2 (with ±0.08V tolerance over the same range). Its RSTIN pin uses a fixed 1.22V comparator reference (±0.03V). These values are confirmed in the "Voltage Threshold Levels" and "Electrical Characteristics" tables of the official MAX6351–MAX6360 datasheet (Rev 7, May 2014), and match the "LT" suffix designation in the ordering guide.

Can MAX6355LTUT operate with supply voltages below 1.2V?

No - the MAX6355LTUT requires VCC1 and VCC2 to be within 1.2V to 5.5V for full specification compliance over the full -40°C to +85°C temperature range. However, its reset output remains valid (i.e., correctly asserted/deasserted) as long as either VCC1 ≥ 1.0V or VCC2 ≥ 1.0V, per Absolute Maximum Ratings and Electrical Characteristics. Operation below 1.2V is outside guaranteed specs and may result in undefined behavior or incomplete internal biasing.

Is MAX6355LTUT pin-compatible with other devices in the MAX6351–MAX6360 family?

Yes, the MAX6355LTUT shares the same 6-pin SOT23 (U6-1) package and pinout as MAX6351, MAX6356, MAX6357, MAX6358, MAX6359, and MAX6360. Pin 1 is RST, Pin 2 is GND, Pin 3 is MR, Pin 4 is VCC2, Pin 5 is RSTIN, and Pin 6 is VCC1. However, functional differences exist: MAX6355LTUT has open-drain RST, while MAX6356LTUT has push-pull RST referenced to VCC1, and MAX6358LTUT adds WDI on Pin 5 instead of RSTIN - so PCB layout is compatible, but firmware and external circuitry must match the specific variant's functionality.