Analog Devices Inc./Maxim Integrated MAX6719UTTED3+

Overview

MAX6719UTTED3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (4.625V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference). It asserts active-low open-drain reset for ≥210ms after any monitored supply drops below threshold or manual reset is triggered, and supports watchdog timer with 35s startup/1.12s normal timeout. Used in multivoltage telecom and industrial systems requiring reliable power-up sequencing and brownout protection.

For engineers reviewing the MAX6719UTTED3+ datasheet, MAX6719UTTED3+ pinout, MAX6719UTTED3+ application, or MAX6719UTTED3+ equivalent, key selection criteria include dual-supply monitoring with factory-trimmed thresholds, RSTIN-based third-voltage supervision down to 0.62V, guaranteed reset validity at VCC1/VCC2 ≥ 0.8V, low 14µA typical supply current, and compatibility with manual reset, watchdog, and power-fail functions.

Technical Context

The MAX6719UTTED3+ implements a dual-threshold voltage monitor for primary (VCC1) and secondary (VCC2) supplies plus a high-impedance RSTIN comparator referenced to a 626.5mV internal bandgap. Its reset logic combines OR-gated fault detection across all three inputs and enforces a minimum 210ms timeout via an internal timer after recovery.

It features an open-drain RST output referenced to VCC1, internal 50kΩ MR pullup, and a dual-mode watchdog with 35s initial timeout (for boot sequences) and 1.12s normal timeout (for runtime monitoring), triggered by WDI edge transitions.

Key Specifications

Pinout & Package

MAX6719UTTED3+ uses a 6-pin SOT23-6 package with exposed pad (not electrically connected), footprint compliant with JEDEC MO-178AB. Pin 1 is marked with dot; device orientation follows standard SOT23 pin 1 indicator.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6720UTTED3+, the MAX6719UTTED3+ offers open-drain RST for safer bidirectional µP interfacing; versus TPS3808G33DBVR, it adds critical RSTIN-based third-rail supervision at higher IQ but broader system coverage.

Availability

MAX6719UTTED3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and portable medical equipment requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6719UTTED3+ 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 analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed specifically for ultra-low-voltage multirail systems needing compact, low-power, triple-supply supervision with flexible reset timing and watchdog functionality.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6719UTTED3+?

The MAX6719UTTED3+ has a factory-trimmed VCC1 reset threshold of 4.625V (±125mV), corresponding to the "T" suffix in the Reset Voltage Threshold Suffix Guide. This value is guaranteed over -40°C to +85°C and ensures reliable detection of 5V rail brownout conditions before system instability occurs. The MAX6719UTTED3+ maintains this precision using on-chip bandgap referencing and laser trimming during production.

Does the MAX6719UTTED3+ support monitoring a third supply voltage, and how is it configured?

Yes, the MAX6719UTTED3+ supports third-supply monitoring via its RSTIN pin, which compares the applied voltage against an internal 626.5mV reference. To configure it for a specific threshold (e.g., 1.2V), use a resistor divider: R1 between the supply and RSTIN, R2 between RSTIN and GND, satisfying V_{EXT_TH} = 626.5mV × (R1 + R2)/R2. The MAX6719UTTED3+'s 25nA max RSTIN input current enables high-value resistors, minimizing power loss in battery-powered systems.

What is the function of the MR pin on the MAX6719UTTED3+, and what are its drive requirements?

The MR pin on the MAX6719UTTED3+ is an active-low manual reset input with an internal 50kΩ pullup to VCC1. Driving MR low for ≥1µs forces an immediate reset assertion, held for the full 210ms timeout period after MR returns high. It accepts TTL/CMOS logic levels and can be driven by open-drain outputs or momentary switches to GND. No external pullup is needed, and the MAX6719UTTED3+ tolerates MR glitches <100ns, making it robust in noisy industrial environments.

How does the watchdog timer operate on the MAX6719UTTED3+, and what are its timing modes?

The MAX6719UTTED3+ watchdog operates in two distinct modes: a 35s minimum startup timeout after any reset event (power-up, MR, or watchdog timeout), allowing full system boot; and a 1.12s minimum normal timeout during steady-state operation. A rising or falling edge on WDI clears the timer. If WDI remains static beyond the active timeout, the MAX6719UTTED3+ asserts RST for 210ms. This dual-mode architecture prevents false resets during boot while ensuring rapid response to software hangs during runtime.

Is the MAX6719UTTED3+ compatible with bidirectional microprocessor reset pins, and what interface considerations apply?

Yes, the MAX6719UTTED3+ is compatible with bidirectional µP reset pins due to its open-drain RST output. This allows safe wired-OR connection without contention, unlike push-pull outputs. A 4.7kΩ series resistor between RST and the µP's reset I/O port is recommended to prevent logic contention if the µP drives high while RST is asserted. The MAX6719UTTED3+'s guaranteed reset validity down to VCC1 = 0.8V further ensures correct logic levels even during deep brownout conditions.