Analog Devices Inc./Maxim Integrated MAX6312EUK29D3+

Overview

MAX6312EUK29D3+ from Maxim Integrated is a precision 5-pin SOT23 programmable supervisory IC that monitors VCC (factory-set 2.9V reset threshold), an adjustable undervoltage input (RST IN_), and a manual-reset input (MR) to assert an active-high push/pull RESET output. It guarantees valid reset assertion down to VCC = 1.0V, features 8µA supply current, and provides 140ms minimum reset timeout - ideal for multivoltage embedded systems requiring reliable power-on and brownout protection.

For engineers reviewing the MAX6312EUK29D3+ datasheet, MAX6312EUK29D3+ pinout, MAX6312EUK29D3+ application, or MAX6312EUK29D3+ equivalent, key selection considerations include its -40°C to +85°C industrial temperature range, factory-trimmed 2.9V ±2.5% VCC threshold, MR-driven reset initiation, dual-supply monitoring capability, and immunity to fast transients on monitored rails.

Technical Context

The MAX6312EUK29D3+ implements a dual-monitoring architecture: one internal factory-trimmed voltage divider sets the primary VCC reset threshold at 2.9V, while a dedicated RST IN_ comparator accepts externally programmed undervoltage thresholds via resistor dividers referenced to a stable 1.23V internal reference. Its active-high push/pull RESET output sources/sinks current without external pull-up, ensuring robust drive into µP reset pins.

Reset assertion is governed by independent comparators and a digital timeout timer: any monitored rail falling below its threshold immediately triggers reset, and the internal timer enforces a guaranteed minimum 140ms deassertion delay after all rails recover. The MR input features a 63.5kΩ internal pull-up and 1.5µs minimum pulse width requirement over temperature.

Key Specifications

Pinout & Package

MAX6312EUK29D3+ is housed in a lead-free 5-pin SOT23 package (package code U5+1), with 0.95mm pitch, 2.9mm × 1.6mm footprint, and thermal pad omitted. Pin 1 is marked with a dot or beveled edge.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6312EUK29D2+, the MAX6312EUK29D3+ provides 7× longer reset hold time for robust boot sequencing; versus TPS3808G33DBVR, it adds dual-input flexibility and manual reset at the cost of higher quiescent current and slightly larger footprint tolerance.

Availability

MAX6312EUK29D3+ is available at Aetrix Electronics and suitable for industrial PLCs, medical patient monitors, automotive infotainment head units, and network edge routers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6312EUK29D3+ 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, communications, and computing applications, with emphasis on reliability, low power, and integration.

The MAX6305–MAX6313 family delivers programmable, multi-input supervisory circuits targeting space-constrained embedded systems needing deterministic reset behavior across multiple voltage domains and environmental conditions.

FAQ

What is the exact factory-set VCC reset threshold for MAX6312EUK29D3+?

The MAX6312EUK29D3+ has a factory-trimmed VCC reset threshold of 2.9V, specified with ±2.5% tolerance over the full -40°C to +85°C temperature range. This value is laser-trimmed during production and confirmed in the Electrical Characteristics table of the official datasheet (Rev 6, page 2). The "29" in the part number explicitly denotes the 2.9V nominal threshold.

Does MAX6312EUK29D3+ support monitoring of a second voltage rail besides VCC?

Yes, MAX6312EUK29D3+ includes a dedicated RST IN_ input that compares an externally applied voltage (via resistor divider) to an internal 1.23V reference. This allows precise undervoltage monitoring of a secondary rail - such as 1.8V, 2.5V, or 5V - independent of the primary 2.9V VCC threshold, enabling true dual-supply supervision in a single SOT23-5 device.

What is the function of the MR pin on MAX6312EUK29D3+ and how is it used?

The MR (Manual Reset) pin on MAX6312EUK29D3+ is an active-low input with an internal 63.5kΩ pull-up resistor. Driving MR low forces an immediate reset assertion, which remains active for the full 140ms timeout period after MR returns high. It supports direct connection to a momentary switch (to GND) or logic signal, requiring no external components for basic implementation.

Is MAX6312EUK29D3+ compatible with 3.3V microcontroller reset inputs?

Yes, MAX6312EUK29D3+ is fully compatible with 3.3V µPs. Its active-high push/pull RESET output sources up to 0.8×VCC (≥2.64V at VCC = 3.3V) and sinks 3.2mA, meeting standard 3.3V CMOS input thresholds. The output remains valid down to VCC = 1.0V, ensuring reliable reset assertion even during deep brownout conditions affecting the 3.3V rail.

What does the "D3" suffix indicate in MAX6312EUK29D3+?

The "D3" suffix in MAX6312EUK29D3+ specifies the factory-programmed reset timeout period: D3 corresponds to a minimum 140ms reset assertion duration after power-up or fault recovery. This is distinct from D1 (1ms), D2 (20ms), and D4 (1120ms), and is selected to ensure adequate timing margin for complex microprocessor and peripheral initialization sequences.