Analog Devices Inc./Maxim Integrated MAX6719UTTWD3+

Overview

MAX6719UTTWD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (1.575V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference) for auxiliary supply monitoring down to 0.62V. It asserts active-low open-drain reset with 210ms minimum timeout and supports manual reset and watchdog timer functions. Used in multivoltage embedded systems requiring reliable power-up sequencing and brownout protection.

For engineers reviewing the MAX6719UTTWD3+ datasheet, MAX6719UTTWD3+ pinout, MAX6719UTTWD3+ application, or MAX6719UTTWD3+ equivalent, key selection criteria include dual/third-supply monitoring capability, guaranteed reset validity down to VCC = 0.8V, low 14µA typical supply current at 3.6V, immunity to short VCC transients, and compatibility with battery-operated and industrial equipment designs.

Technical Context

The MAX6719UTTWD3+ implements independent voltage comparators for primary (VCC1), secondary (VCC2), and auxiliary (RSTIN) supplies, each with factory-trimmed thresholds and 20ppm/°C tempco. Its reset logic combines OR-gated fault detection across all three inputs and enforces a fixed 210ms minimum timeout after recovery, ensuring stable µP initialization before release.

It features a dual-mode watchdog timer: 35s minimum startup period for system boot, followed by 1.12s minimum normal timeout triggered by WDI edge transitions. The open-drain RST output is referenced to VCC1 and requires external pullup; MR input includes internal 50kΩ pullup to VCC1 and 200ns propagation delay.

Key Specifications

Pinout & Package

MAX6719UTTWD3+ uses a 6-pin SOT23-6 package with gull-wing leads, 1.27mm pitch, and 2.9mm × 1.6mm footprint. Pin 1 is marked with dot; device orientation follows JEDEC MO-178 standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6719UTTWD3+, MAX6720UTTWD3+ offers push-pull drive for lower VOL but forfeits reset bus sharing, while TPS3808G33DBVR reduces functionality to dual monitoring and lacks RSTIN flexibility-making MAX6719UTTWD3+ optimal for compact triple-rail integrity where open-drain interoperability is required.

Availability

MAX6719UTTWD3+ is available at Aetrix Electronics and suitable for industrial PLC power sequencing, telecom line card voltage monitoring, portable medical device battery backup, and embedded network router power management requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6719UTTWD3+ 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 power, sensing, and interface applications, with emphasis on reliability and integration for demanding industrial and communications systems.

The MAX6715–MAX6729 family delivers compact, ultra-low-power supervisory solutions for multivoltage embedded systems, targeting applications where board space, quiescent current, and robust reset timing are critical design constraints.

FAQ

What is the exact reset threshold voltage for VCC1 on MAX6719UTTWD3+?

The MAX6719UTTWD3+ has a factory-trimmed VCC1 reset threshold of 1.575V (typical), with min/max values of 1.530V and 1.620V across temperature and process variation. This value is encoded in the part number suffix 'T' per Maxim's Reset Voltage Threshold Suffix Guide and is guaranteed over the full -40°C to +85°C operating range. The MAX6719UTTWD3+ uses this threshold to assert reset when the primary 1.8V supply drops below specification.

Does MAX6719UTTWD3+ support monitoring a negative supply voltage?

Yes - the MAX6719UTTWD3+ can monitor negative supplies using its RSTIN input with an external resistor divider, as documented in Figure 3b of the datasheet. When configured for negative rail monitoring, RSTIN compares the divided voltage against its 626.5mV internal reference, and reset asserts when the negative supply magnitude exceeds the trip point. The MAX6719UTTWD3+ does not require level-shifting circuitry, making it suitable for telecom -48V supervision.

What is the function of the 'D3' suffix in MAX6719UTTWD3+?

The 'D3' suffix in MAX6719UTTWD3+ specifies a 210ms minimum reset timeout period, per Maxim's Reset Timeout Period Suffix Guide. This value determines the duration RST remains asserted after all monitored supplies recover above their thresholds. The D3 option provides sufficient hold time for complex µP initialization sequences while avoiding excessive delays in fast-recovery systems. All timing parameters for MAX6719UTTWD3+ are production-tested and guaranteed.

Can MAX6719UTTWD3+ operate with VCC1 below 1.8V?

Yes - the MAX6719UTTWD3+ is guaranteed to maintain valid reset output logic state with VCC1 or VCC2 as low as 0.8V, per Absolute Maximum Ratings and Electrical Characteristics tables. While VCC1 nominal range is 1.8V–5.0V, the device continues asserting reset correctly during deep brownout conditions down to 0.8V, enabling fail-safe behavior in low-voltage battery-depleted states. The MAX6719UTTWD3+ achieves this via internal biasing optimized for sub-1V operation.

Is there a watchdog timer in MAX6719UTTWD3+, and how is it configured?

Yes - the MAX6719UTTWD3+ includes a dual-mode watchdog timer with 35s minimum startup period and 1.12s minimum normal timeout. It is enabled by default and triggered by WDI pin transitions; no external components or configuration registers are needed. After power-up or reset, the long startup mode allows full system boot, then switches to short timeout upon first WDI edge. The MAX6719UTTWD3+ watchdog requires no software initialization and operates autonomously once WDI is connected to a toggling µP I/O line.