Analog Devices Inc./Maxim Integrated MAX6719UTVHD3+

Overview

MAX6719UTVHD3+ 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 (626.5mV 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 telecom power management and multivoltage embedded systems.

For engineers reviewing the MAX6719UTVHD3+ datasheet, MAX6719UTVHD3+ pinout, MAX6719UTVHD3+ application, or MAX6719UTVHD3+ 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, and compatibility with battery-backed systems requiring low quiescent current (14µA typ).

Technical Context

The MAX6719UTVHD3+ implements independent dual-threshold comparators for VCC1 and VCC2, plus a high-impedance RSTIN input referenced to a 626.5mV internal bandgap, enabling precise third-supply monitoring via external resistor divider. Its reset logic combines OR-gated fault detection (VCC1 undervoltage, VCC2 undervoltage, RSTIN undervoltage, MR assertion) with a monolithic timeout timer.

It features a dual-mode watchdog: 35s minimum initial timeout after power-up/manual reset, transitioning to 1.12s minimum normal timeout after first WDI edge; reset output is open-drain, requiring external pullup, and remains asserted for 210ms min after all fault conditions clear.

Key Specifications

Pinout & Package

MAX6719UTVHD3+ is housed in a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), surface-mount, RoHS-compliant, with gull-wing leads and thermal pad not present.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6719UTVHD3+, MAX6720UTVHD3+ offers push-pull drive for simplified layout but loses open-drain flexibility with bidirectional µP pins, while TPS3808G33DBVR reduces current draw by 82% but sacrifices triple-monitoring and watchdog functionality - making MAX6719UTVHD3+ optimal for complex multirail systems requiring fault isolation and software supervision.

Availability

MAX6719UTVHD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, portable medical devices, and set-top box designs requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6719UTVHD3+ 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 high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed specifically for space-constrained, multivoltage embedded systems needing reliable power-supply monitoring, manual reset, and watchdog supervision - with emphasis on low quiescent current and guaranteed operation down to 0.8V.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6719UTVHD3+?

The MAX6719UTVHD3+ has a factory-trimmed VCC1 reset threshold of 4.625V (typical), with guaranteed limits of 4.500V (min) and 4.750V (max) at +25°C, and ±0.5% hysteresis referenced to typical threshold. This value is encoded in the "TV" suffix per Maxim's Reset Voltage Threshold Suffix Guide and applies across the full -40°C to +85°C operating range.

Does the MAX6719UTVHD3+ support monitoring a third supply voltage, and how is it configured?

Yes, the MAX6719UTVHD3+ supports third-supply monitoring via its RSTIN pin, which compares the applied voltage against an internal 626.5mV reference. To monitor a custom voltage (e.g., 1.2V), connect a resistor divider from the supply to GND with RSTIN at the midpoint - the threshold is calculated as V_EXT = 626.5mV × (R1 + R2)/R2. The MAX6719UTVHD3+ datasheet provides design examples and tolerance guidance.

What is the reset timeout period for the MAX6719UTVHD3+, and is it adjustable?

The MAX6719UTVHD3+ has a fixed reset timeout period of 210ms (minimum), indicated by the "D3" suffix in its part number. This timeout is factory-programmed and non-adjustable; it defines the minimum duration the RST output remains asserted after all monitored voltages recover above their thresholds or after MR release. Typical value is 210ms, with max 280ms over temperature.

Can the MAX6719UTVHD3+ operate with VCC1 below 1.8V, and what is the minimum functional voltage?

Yes, the MAX6719UTVHD3+ is guaranteed to assert a valid reset output as long as either VCC1 or VCC2 remains ≥ 0.8V - explicitly confirmed in the Absolute Maximum Ratings and Detailed Description sections. While VCC1 nominal range is 1.8V–5.0V, the device maintains correct reset logic state down to 0.8V, enabling brownout detection in low-voltage battery systems.

Is the watchdog function enabled by default on the MAX6719UTVHD3+, and how is it initialized?

The watchdog function on the MAX6719UTVHD3+ is always active and requires no configuration. After power-up or any reset event, it enters a 35s (minimum) startup mode; the 1.12s (minimum) normal timeout begins only after the first rising or falling edge is detected on the WDI pin. No external components or register writes are needed - WDI is a dedicated input pin that must be toggled by the host µP.