Analog Devices Inc./Maxim Integrated MAX6719AUTZWD3+

Overview

The MAX6719AUTZWD3+ from Maxim Integrated is a dual-voltage, ultra-low-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (4.625V threshold) and VCC2 (3.075V threshold) with 210ms reset timeout, watchdog timer (35s startup / 1.12s normal), and adjustable RSTIN input (626mV reference). It asserts active-low open-drain RST on supply undervoltage, manual reset, or watchdog timeout-used in telecom power management and industrial embedded controllers requiring guaranteed reset validity down to 0.8V.

For engineers reviewing the MAX6719AUTZWD3+ datasheet, MAX6719AUTZWD3+ pinout, MAX6719AUTZWD3+ application, or MAX6719AUTZWD3+ equivalent, key selection criteria include dual-supply threshold accuracy (±1.5% over -40°C to +125°C), RSTIN-adjustable third-voltage monitoring capability, watchdog disable via floating WDI, and compatibility with 1.8V/0.9V core-I/O rail systems.

Technical Context

This device implements dual independent voltage comparators with factory-trimmed thresholds for VCC1 and VCC2, plus a high-impedance RSTIN comparator referenced to a 626mV internal bandgap. Reset assertion logic combines ORed fault conditions (VCC1/VCC2 undervoltage, MR low, RSTIN low, or WDI timeout) with a monolithic timeout counter ensuring minimum 210ms reset hold time after recovery.

The watchdog operates in dual-mode: a 35s minimum startup period post-reset enables full system boot before watchdog supervision begins, followed by a 1.12s minimum normal timeout period triggered by missing WDI edges. RST output is open-drain, requiring external pullup; MR includes 50kΩ internal pullup to VCC1; all outputs remain valid while either VCC1 or VCC2 ≥ 0.8V.

Key Specifications

Pinout & Package

MAX6719AUTZWD3+ uses a 6-pin SOT23 package (2.9mm × 1.6mm × 1.1mm height) with gull-wing leads, RoHS-compliant matte-tin plating, and thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6719AUTZWD3+, MAX6720AUTZWD3+ simplifies reset net termination but constrains µP interface compatibility, while TPS3808G33DBVR reduces supply current by 87% yet sacrifices dual-supply supervision and RSTIN flexibility required for complex power architectures.

Availability

MAX6719AUTZWD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and automotive ADAS applications requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6719AUTZWD3+ 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, mixed-signal, and power management ICs for demanding industrial, automotive, and communications applications.

The MAX6715A–MAX6729A family delivers ultra-low-voltage supervisory functions targeting multirail embedded systems where reliability, small footprint, and guaranteed operation down to 0.8V are critical design requirements.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on MAX6719AUTZWD3+?

The MAX6719AUTZWD3+ has factory-trimmed reset thresholds of 4.625V for VCC1 and 3.075V for VCC2, with ±1.5% tolerance over the full -40°C to +125°C temperature range. These values are encoded in the part number suffix 'Z' (VCC1) and 'W' (VCC2) per Maxim's Reset Voltage Threshold Suffix Guide, and are confirmed in the Electrical Characteristics table of the official datasheet.

Does MAX6719AUTZWD3+ support monitoring a third voltage supply?

Yes, MAX6719AUTZWD3+ supports third-voltage monitoring via its RSTIN pin, which features a precise 626mV internal reference. By connecting an external resistor divider from the auxiliary supply to RSTIN and GND, users can set custom trip points down to 0.62V - a capability explicitly documented in the Adjustable Input Voltage section and Figure 1 of the MAX6719AUTZWD3+ datasheet.

What is the watchdog timeout behavior of MAX6719AUTZWD3+?

MAX6719AUTZWD3+ implements a dual-mode watchdog: a 35s minimum startup period after any reset event (power-up, MR, or watchdog timeout), followed by a 1.12s minimum normal timeout period. The first WDI edge after startup triggers transition to normal mode; absence of edges longer than 1.12s thereafter asserts RST. This behavior is specified in the Watchdog Timeout Period parameter and Figure 2 of the datasheet.

Is the RST output of MAX6719AUTZWD3+ push-pull or open-drain?

The RST output of MAX6719AUTZWD3+ is open-drain, as confirmed by the Pin Description table (Pin 1 function: "Active-Low Reset Output, Open-Drain or Push-Pull") and the Ordering Information footnote stating MAX6719A devices contain open-drain outputs. This requires an external pullup resistor to VCC1, unlike push-pull variants such as MAX6720AUTZWD3+.

What is the minimum supply voltage at which MAX6719AUTZWD3+ guarantees valid reset output?

MAX6719AUTZWD3+ guarantees correct reset output logic state when either VCC1 or VCC2 remains greater than 0.8V, as stated in the General Description and Ensuring a Valid Reset Output section. This specification ensures reliable brownout detection in ultra-low-voltage systems where supplies may dip near 1.0V during transient load steps.