Analog Devices Inc./Maxim Integrated MAX6419UK31+

Overview

MAX6419UK31+ from Maxim Integrated is an active-high, push-pull microprocessor reset supervisor IC for dual-voltage monitoring systems. It features a factory-trimmed VCC reset threshold of 3.075V (suffix "31"), an adjustable RESET IN input (1.26V threshold), capacitor-programmable reset timeout delay, and operates across -40°C to +125°C. Designed for automotive and industrial embedded controllers requiring reliable brownout detection and manual reset capability.

For engineers reviewing the MAX6419UK31+ datasheet, MAX6419UK31+ pinout, MAX6419UK31+ application, or MAX6419UK31+ equivalent, key selection criteria include its dual-threshold architecture (fixed + adjustable), 1.7µA quiescent current, guaranteed reset validity down to VCC = 1V, and SOT23-5 package compatibility with high-temperature PCB layouts.

Technical Context

The MAX6419UK31+ integrates two independent voltage monitoring paths: one laser-trimmed comparator for VCC (3.075V ±2.5% over temperature) and a high-impedance adjustable comparator for external VMON_TH via resistor divider on RESET IN (1.26V reference). Reset assertion occurs if either input falls below its threshold or MR is pulled low.

Its reset timeout period is set by an external capacitor on SRT, generating a precise 240nA ramp current charging CSRT to 0.65V - enabling programmable delays from 275µs (CSRT = 0F) up to milliseconds. The active-high push-pull RESET output drives logic-compatible loads with VOL ≤ 0.4V at 3.2mA and VOH ≥ 0.8×VCC at 800µA.

Key Specifications

Pinout & Package

SOT23-5 package: compact, surface-mount, thermally robust, and RoHS-compliant (indicated by '+' suffix). Pin 1 = RESET (active-high push-pull), Pin 2 = GND, Pin 3 = RESET IN (adjustable threshold input), Pin 4 = MR (manual reset, internally pulled up to VCC via 20kΩ), Pin 5 = SRT (capacitor-connected timeout programming node).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6418UK31+, the MAX6419UK31+ provides native active-high reset signaling without level-shifting, while versus TLV803EA30DBZR it delivers essential dual-voltage supervision and field-configurable timeout - critical for safety-certified and multi-rail embedded designs.

Availability

MAX6419UK31+ is available at Aetrix Electronics and suitable for automotive engine control units, medical infusion pump controllers, industrial PLC I/O modules, and smart energy meter MCUs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6419UK31+ 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, automotive, and computing applications.

The MAX6412–MAX6420 product line delivers ultra-low-power, temperature-robust reset supervision with flexible threshold and timing configurations - engineered specifically for mission-critical embedded systems demanding reliability under voltage stress and thermal extremes.

FAQ

What is the factory-set VCC reset threshold for MAX6419UK31+?

The MAX6419UK31+ has a nominal VCC reset threshold of 3.075V, corresponding to suffix "31" per Table 1 in the datasheet. This value is laser-trimmed with ±2.5% accuracy over the full -40°C to +125°C operating range. The actual threshold is guaranteed between 2.998V (min) and 3.152V (max) at temperature extremes, ensuring consistent brownout detection in automotive and industrial applications.

How do I calculate the external capacitor value for a specific reset timeout on MAX6419UK31+?

To set a desired reset timeout period tRP (in seconds) for MAX6419UK31+, use the formula CSRT = (tRP − 275µs) / 2.71×10⁶, where CSRT is in farads. For example, a 100ms timeout requires CSRT ≈ 36.8nF. Use low-leakage ceramic capacitors (<10nA) and keep the SRT trace short and isolated to avoid timing errors caused by stray capacitance or noise coupling.

Can MAX6419UK31+ monitor a 1.2V supply rail?

Yes, MAX6419UK31+ can monitor a 1.2V rail using its RESET IN pin. Since the internal reference is 1.26V, a 1.2V rail falls slightly below threshold and will assert reset. To monitor lower voltages accurately, scale the rail upward using a resistor divider: e.g., for a true 1.2V trip point, configure R1/R2 so that 1.2V × (R1+R2)/R2 = 1.26V. The MAX6419UK31+'s 10nA RESET IN leakage enables high-impedance dividers with minimal error.

Does MAX6419UK31+ require an external pull-up resistor on the RESET pin?

No, MAX6419UK31+ does not require an external pull-up resistor on the RESET pin because it features an active-high push-pull output. The internal driver actively sources current to pull RESET high and sinks current to pull it low. This eliminates external components, reduces board space, and ensures fast, rail-to-rail logic transitions compatible with modern µP reset inputs - a key advantage over open-drain alternatives like MAX6420UK31+.

What is the function of the MR pin on MAX6419UK31+ and how should it be used?

The MR (Manual Reset) pin on MAX6419UK31+ is an active-low input with an internal 20kΩ pull-up to VCC. Pulling MR low asserts RESET for the full timeout period, even if VCC and RESET IN remain above threshold. For implementation, connect a normally open momentary switch between MR and GND. No external debounce is needed due to the built-in timeout - releasing the switch initiates a clean, timed reset sequence, making MAX6419UK31+ ideal for field-service and diagnostic reset functions.