Analog Devices Inc./Maxim Integrated MAX6719UTVDD3+T

Overview

MAX6719UTVDD3+T 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 third supply via RSTIN (626mV reference). It asserts active-low open-drain reset for ≥210ms after any monitored voltage drops below threshold or manual reset is triggered, and supports watchdog timeout with 35s startup and 1.12s normal mode. Used in multivoltage telecom and portable systems requiring reliable power sequencing and brownout protection.

For engineers reviewing the MAX6719UTVDD3+T datasheet, MAX6719UTVDD3+T pinout, MAX6719UTVDD3+T application, or MAX6719UTVDD3+T equivalent, key selection criteria include dual-supply monitoring with factory-trimmed thresholds, RSTIN-based auxiliary voltage supervision down to 0.62V, guaranteed reset validity at VCC1/VCC2 ≥ 0.8V, low 14µA typical supply current, and compatibility with noisy industrial or battery-operated environments.

Technical Context

The MAX6719UTVDD3+T implements independent dual-threshold comparators for VCC1 and VCC2, plus a high-impedance RSTIN input referenced to a 626mV internal bandgap. Its reset logic combines OR-ed fault detection (VCC1 undervoltage, VCC2 undervoltage, RSTIN undervoltage, MR assertion) with a monolithic timeout timer ensuring minimum 210ms reset pulse width after recovery.

It features a dual-mode watchdog: 35s minimum initial timeout after power-up/manual reset, transitioning to 1.12s minimum normal timeout upon first WDI edge detection. The open-drain RST output requires external pullup and remains valid down to VCC1 or VCC2 = 0.8V, enabling robust operation during deep brownouts.

Key Specifications

Pinout & Package

MAX6719UTVDD3+T is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts in portable and telecom equipment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6720UTVDD3+T and TPS3808G33DBVR, the MAX6719UTVDD3+T uniquely delivers triple-supply monitoring with open-drain flexibility and dual-mode watchdog-making it optimal for complex multirail systems requiring both precision and autonomy.

Availability

MAX6719UTVDD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, portable medical devices, and industrial PLCs requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6719UTVDD3+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 demanding industrial, automotive, and communications applications, emphasizing reliability, integration, and low-power operation.

The MAX6715–MAX6729 family was engineered specifically for multivoltage embedded systems needing compact, accurate, and autonomous power supervision-enabling robust reset generation without software dependency.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6719UTVDD3+T?

The MAX6719UTVDD3+T has a factory-trimmed VCC1 reset threshold of 4.625V, with a guaranteed tolerance of ±125mV over temperature. This value is encoded in the "VD" suffix per Maxim's Reset Voltage Threshold Suffix Guide and is confirmed in the Electrical Characteristics table of the official datasheet. The MAX6719UTVDD3+T uses this precise threshold to assert reset before a nominal 5V rail collapses below system operational limits.

Does the MAX6719UTVDD3+T support monitoring a third voltage, and how is it configured?

Yes, the MAX6719UTVDD3+T supports third-supply monitoring via its RSTIN pin, which references an internal 626mV bandgap. To configure, connect an external resistor divider from the target supply to GND, with the midpoint fed to RSTIN. The threshold is calculated as V_EXT = 626mV × (R1 + R2)/R2. This feature is explicitly enabled in the MAX6719UTVDD3+T per the Selector Guide and Functional Diagram, distinguishing it from dual-monitor variants like MAX6715.

What is the reset timeout period for the MAX6719UTVDD3+T, and is it adjustable?

The MAX6719UTVDD3+T has a fixed minimum reset timeout period of 210ms, indicated by the "D3" suffix in its part number per the Reset Timeout Period Suffix Guide. This value is not user-adjustable via external components-it is set by internal capacitor sizing and guaranteed across -40°C to +85°C. The MAX6719UTVDD3+T maintains RST low for this full duration after all monitored supplies recover, ensuring reliable processor initialization.

Is the MAX6719UTVDD3+T compatible with bidirectional microprocessor reset pins?

Yes, the MAX6719UTVDD3+T's open-drain RST output is inherently compatible with bidirectional µP reset I/O pins, as confirmed in the Applications Information section. No series resistor is required for basic interfacing; however, if contention is observed in systems also using push-pull outputs, a 4.7kΩ resistor between RST and the µP pin (per Figure 4) resolves potential logic conflicts. This behavior is intrinsic to the MAX6719UTVDD3+T's output architecture.

What watchdog functionality does the MAX6719UTVDD3+T provide, and how is it activated?

The MAX6719UTVDD3+T includes a dual-mode watchdog timer with a 35s minimum startup period after reset and a 1.12s minimum normal timeout. Activation requires connecting WDI to a µP GPIO or bus line that toggles within the timeout window. The MAX6719UTVDD3+T clears the timer on any rising or falling edge at WDI; failure to update within 1.12s triggers reset. This function is enabled by default and requires no configuration-only proper WDI routing.