Analog Devices Inc./Maxim Integrated MAX6351TWUT+T

Overview

The MAX6351TWUT+T from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with two active-low push-pull reset outputs-one referenced to VCC1 (3.08V threshold) and one to VCC2 (1.67V threshold)-supporting multivoltage systems in industrial controllers and portable equipment. It features 20µA supply current, 100ms min reset pulse width, guaranteed RESET validity down to VCC1 or VCC2 = 1.0V, and operates across –40°C to +85°C.

For engineers reviewing the MAX6351TWUT+T datasheet, MAX6351TWUT+T pinout, MAX6351TWUT+T application, or MAX6351TWUT+T equivalent, key selection criteria include dual-supply monitoring thresholds, push-pull output referencing, manual-reset debouncing, watchdog timer absence (this variant lacks WDI), and SOT23-6 package compatibility with multivoltage embedded power sequencing.

Technical Context

The MAX6351TWUT+T monitors two independent supply rails-VCC1 at 3.08V and VCC2 at 1.67V-with precision factory-set thresholds and ±0.05V typical tolerance over temperature. Its dual push-pull reset outputs (RST1 referenced to VCC1, RST2 to VCC2) assert simultaneously when either supply falls below its trip point, and remain valid as long as either VCC ≥ 1.0V.

No watchdog timer or third-voltage monitor is present; this variant belongs to the base MAX6351 family without WDI or RSTIN functionality. It uses BiCMOS process technology, supports TTL/CMOS-compatible manual reset with 1µs minimum pulse width, and delivers power-supply transient immunity up to 250µs for 100mV overdrive.

Key Specifications

Pinout & Package

MAX6351TWUT+T is housed in a lead(Pb)-free 6-pin SOT23 package (U6-1 outline, land pattern 90-0175), with 1.0mm pitch, 2.9mm × 1.6mm body, and thermal pad not included.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6351TZUT+T and MAX6353TWUK+T, the MAX6351TWUT+T uniquely supports 1.67V secondary rail supervision with dual push-pull outputs-enabling robust reset coordination in ultra-low-voltage multirail systems where alternatives either miss the low-threshold requirement or omit dual-output capability.

Availability

MAX6351TWUT+T is available at Aetrix Electronics and suitable for industrial PLC controllers, portable medical monitors, multivoltage IoT edge nodes, and automotive body control modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MAX6351TWUT+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 and mixed-signal ICs for industrial, communications, computing, and consumer applications.

The MAX6351–MAX6360 product line delivers multivoltage microprocessor supervision with factory-trimmed thresholds, low quiescent current, and robust reset timing-targeted at systems requiring coordinated power-up/down sequencing across heterogeneous voltage domains.

FAQ

What is the function of the MAX6351TWUT+T in a dual-supply system?

The MAX6351TWUT+T monitors two independent supply voltages-VCC1 at 3.08V and VCC2 at 1.67V-and asserts two active-low push-pull reset outputs (RST1 referenced to VCC1, RST2 to VCC2) whenever either supply falls below its threshold. This ensures synchronized, rail-specific reset signaling critical for reliable boot in multivoltage embedded systems. The MAX6351TWUT+T maintains reset validity down to 1.0V on either rail, supporting brownout resilience.

Does the MAX6351TWUT+T include a watchdog timer?

No, the MAX6351TWUT+T does not include a watchdog timer. It belongs to the base MAX6351 series, which provides dual-voltage supervision and dual push-pull reset outputs but omits the WDI pin and associated timeout circuitry found in MAX6358/MAX6359/MAX6360 variants. The MAX6351TWUT+T pinout has no WDI terminal; pins are dedicated to RST1, GND, MR, VCC2, RST2, and VCC1.

What are the absolute maximum ratings for VCC1 and VCC2 on the MAX6351TWUT+T?

The MAX6351TWUT+T specifies absolute maximum ratings of –0.3V to +6V for both VCC1 and VCC2 relative to GND. However, functional operation is guaranteed only within 1.2V to 5.5V over the full –40°C to +85°C temperature range. Operation below 1.2V is permitted only for brownout detection down to 1.0V, where RESET remains valid but other functions may be unguaranteed.

How does the manual reset (MR) input behave on the MAX6351TWUT+T?

The MR input on the MAX6351TWUT+T is an active-low, debounced TTL/CMOS-compatible signal. A low pulse ≥1µs forces immediate reset assertion on both RST1 and RST2, which persists for the timeout period after MR returns high. No external pull-up is required-the MAX6351TWUT+T includes an internal MR pullup resistor (32–100kΩ). MR voltage must not exceed VCC1, and unused MR should be tied to VCC1.

Can the MAX6351TWUT+T supervise a 1.6V rail and a 3.0V rail simultaneously?

Yes-the MAX6351TWUT+T is specifically configured to supervise a 3.08V rail (VCC1) and a 1.67V rail (VCC2) simultaneously. Its factory-trimmed thresholds match standard 3.0V and 1.6V–1.8V supply domains, and its dual push-pull outputs (RST1 referenced to VCC1, RST2 to VCC2) provide rail-specific reset signaling without external level-shifting. This makes the MAX6351TWUT+T ideal for modern low-voltage SoC and sensor interface applications.