Analog Devices Inc./Maxim Integrated MAX6312UK43D3+

Overview

MAX6312UK43D3+ from Maxim Integrated is a 5-pin SOT23 programmable supervisory circuit that monitors VCC (factory-set 4.3V threshold), an adjustable undervoltage input (RST IN_), and a manual-reset input (MR) to assert an active-high push/pull RESET signal. It features 140ms minimum reset timeout, 8µA supply current, and guaranteed RESET validity down to VCC = 1V. It is used in multivoltage embedded systems requiring reliable power-on and brownout reset for microcontrollers.

For engineers reviewing the MAX6312UK43D3+ datasheet, MAX6312UK43D3+ pinout, MAX6312UK43D3+ application, or MAX6312UK43D3+ equivalent, key selection considerations include its 4.3V VCC reset threshold tolerance (±2.5% over –40°C to +85°C), MR input compatibility with TTL/CMOS logic, immunity to fast VCC transients, and absence of external components required for basic operation.

Technical Context

The MAX6312UK43D3+ implements a factory-trimmed internal voltage divider to monitor VCC against a precise 4.3V threshold, while also accepting an external resistor divider on RST IN_ to monitor a second supply. Its active-high push/pull RESET output sources/sinks current without requiring an external pull-up.

It integrates a 140ms minimum reset timeout timer that restarts upon any monitored supply falling below its threshold or MR assertion. The MR input includes a 63.5kΩ internal pull-up and supports noise-immune manual reset via momentary switch to GND.

Key Specifications

Pinout & Package

MAX6312UK43D3+ is housed in a lead-free 5-pin SOT23 package (package code U5+1), measuring 2.9mm × 1.6mm × 1.1mm, suitable for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6312UK43D2+, the MAX6312UK43D3+ provides longer reset hold time for slower power rails; compared with TPS3808G33DBVR, it offers dual-supply monitoring and manual reset at higher quiescent current but with integrated push/pull output.

Availability

MAX6312UK43D3+ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical handheld monitors, automotive body control modules, point-of-sale terminals, and multivoltage embedded systems requiring stable component supply across extended temperature ranges.

Supply support for MAX6312UK43D3+ 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 power management, sensing, and interface applications in industrial, computing, and communications markets.

The MAX6305–MAX6313 family delivers compact, low-power supervisory circuits with factory-programmed thresholds and multiple monitoring inputs, targeting space- and power-constrained embedded systems needing robust reset functionality.

FAQ

What is the exact factory-set VCC reset threshold for MAX6312UK43D3+?

The MAX6312UK43D3+ has a factory-trimmed VCC reset threshold of 4.3V, specified with ±2.5% tolerance over the full operating temperature range of –40°C to +85°C. This value is permanently programmed into the device during manufacturing and cannot be adjusted externally. The "43" in the part number explicitly denotes the 4.3V nominal threshold per Maxim's ordering convention.

Does MAX6312UK43D3+ require external components for basic reset functionality?

No, MAX6312UK43D3+ operates autonomously with no external components required for core VCC supervision and reset generation. Its factory-set 4.3V threshold, 140ms timeout, and push/pull RESET output eliminate the need for pull-up resistors or timing capacitors. External resistors are only needed if using the RST IN_ input to monitor a secondary supply.

How does the manual-reset (MR) input function on MAX6312UK43D3+?

The MR input on MAX6312UK43D3+ is an active-low signal with an internal 63.5kΩ pull-up resistor. Pulling MR to GND forces an immediate RESET assertion, which remains active for the full 140ms timeout after MR returns high. It accepts TTL- or CMOS-level logic and supports direct connection to a momentary switch without debounce circuitry, simplifying hardware reset implementation.

What is the minimum VCC voltage at which MAX6312UK43D3+ guarantees valid RESET output?

MAX6312UK43D3+ guarantees valid RESET output down to VCC = 1V. Below this voltage, the push/pull driver's sourcing/sinking capability degrades, and RESET may become indeterminate. For applications requiring deterministic reset behavior below 1V, an external pull-up or pull-down resistor (e.g., 100kΩ to VCC or GND) is recommended per Maxim's application guidance.

Can MAX6312UK43D3+ monitor a second voltage rail besides VCC?

Yes, MAX6312UK43D3+ includes the RST IN_ pin to monitor a second supply. By connecting an external resistor divider between the secondary rail and GND, with the junction fed to RST IN_, the device asserts RESET when that rail falls below 1.23V - enabling customizable undervoltage detection for auxiliary supplies such as 3.3V, 2.5V, or 1.8V domains.