Analog Devices Inc./Maxim Integrated MAX6307UK31D3+

Overview

MAX6307UK31D3+ from Maxim Integrated is a 5-pin SOT23 programmable supervisory IC that monitors VCC, an adjustable undervoltage input (RST IN), and an adjustable overvoltage input (OVRST IN) to assert a push/pull active-low RESET output. It features a factory-set 3.1V ±2.5% VCC reset threshold, 140ms (min) reset timeout, 8µA supply current, and guaranteed RESET validity down to VCC = 1V. It is used in multivoltage embedded systems requiring robust brownout and transient immunity.

For engineers reviewing the MAX6307UK31D3+ datasheet, MAX6307UK31D3+ pinout, MAX6307UK31D3+ application, or MAX6307UK31D3+ equivalent, key selection considerations include its triple-input monitoring architecture (VCC + RST IN + OVRST IN), fixed 140ms timeout, lead-free SOT23-5 package, and compatibility with 3.3V/5V mixed-rail systems where precise voltage supervision and manual-reset capability are required.

Technical Context

The MAX6307UK31D3+ implements a triple-comparator architecture: one internal factory-trimmed divider for VCC monitoring at 3.1V nominal, one external-resistor-programmable undervoltage comparator on RST IN (threshold = 1.23V reference), and one external-resistor-programmable overvoltage comparator on OVRST IN (same 1.23V reference). All comparators feature built-in hysteresis (2.5mV) and immunity to fast transients.

Its push/pull RESET output drives low actively (VOL ≤ 0.3V at ISINK = 1.2mA) and high actively (VOH ≥ 0.8 × VCC at ISOURCE = 150µA), ensuring valid logic levels across VCC = 1.0V to 5.5V. The internal reset timer guarantees minimum 140ms assertion after all monitored voltages return to regulation, with temperature stability of ±0.5% over –40°C to +85°C.

Key Specifications

Pinout & Package

MAX6307UK31D3+ is housed in a RoHS-compliant, lead-free 5-pin SOT23 package (package code U5+1, outline 21-0057), optimized for space-constrained PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6307UK31D2+, the MAX6307UK31D3+ provides extended reset hold time critical for complex boot sequences; compared with TPS3808G33DBVR, it delivers unique triple-input supervision at the cost of higher quiescent current and absence of ultra-low-power optimization.

Availability

MAX6307UK31D3+ is available at Aetrix Electronics and suitable for industrial control systems, portable medical devices, automotive body electronics, and networking equipment requiring stable component supply with full traceability and long-term lifecycle support.

Supply support for MAX6307UK31D3+ 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, automotive, and communications applications, with emphasis on reliability, integration, and power efficiency.

The MAX6305–MAX6313 family was engineered specifically for multivoltage microprocessor supervision in space- and power-constrained systems, delivering factory-programmed accuracy, transient immunity, and triple-input flexibility without external components.

FAQ

What is the factory-set VCC reset threshold for MAX6307UK31D3+?

The MAX6307UK31D3+ has a factory-trimmed VCC reset threshold of 3.1V, specified with ±2.5% tolerance over the full operating temperature range of –40°C to +85°C. This value is permanently programmed during wafer sort and cannot be adjusted. The "31" in the part number directly encodes the 3.1V nominal threshold per Maxim's ordering convention.

Does MAX6307UK31D3+ support manual reset functionality?

Yes, the MAX6307UK31D3+ includes a dedicated MR (manual reset) input on pin 3. A logic-low pulse ≥1.5µs on MR forces RESET assertion for the full 140ms timeout period, even if all monitored supplies remain within threshold. An internal 63.5kΩ pullup resistor allows direct connection of a momentary switch to GND without external components.

Can MAX6307UK31D3+ monitor both undervoltage and overvoltage on the same external rail?

Yes - the MAX6307UK31D3+ uses separate pins for this purpose: RST IN (pin 3) monitors for undervoltage using a resistor divider referenced to the 1.23V internal bandgap, while OVRST IN (pin 4) monitors for overvoltage using the same reference. Both inputs accept standard resistor-divider configurations and provide independent reset assertion paths.

What is the minimum VCC voltage at which MAX6307UK31D3+ guarantees valid RESET output?

The MAX6307UK31D3+ guarantees RESET remains a valid logic-low output down to VCC = 1.0V (with ISINK = 500µA), and a valid logic-high output down to VCC = 1.0V (with ISOURCE = 10µA). Below 1.0V, output drive capability degrades; the device is not characterized or guaranteed for operation at VCC < 1.0V.

Is MAX6307UK31D3+ pin-compatible with other members of the MAX6305–MAX6313 family?

Yes - all MAX6305–MAX6313 devices share identical 5-pin SOT23 pinouts and pin functions. The MAX6307UK31D3+ uses the same RESET/GND/RST IN/OVRST IN/VCC assignment as MAX6307/MAX6310/MAX6313 variants. However, functional differences (e.g., presence of OVRST IN, reset output type) mean electrical compatibility must be verified per application.