Analog Devices Inc./Maxim Integrated MAX6386LT31D3+T

Overview

MAX6386LT31D3+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 3.08V reset threshold (±2.5% over –40°C to +125°C), and 140ms minimum VCC reset timeout. It features a debounced manual reset input (MR) with internal 63kΩ pullup, operates down to VCC = 1.0V, and consumes only 3μA at 1.8V - used in portable battery-powered equipment for reliable power-on reset and brownout protection.

For engineers reviewing the MAX6386LT31D3+T datasheet, MAX6386LT31D3+T pinout, MAX6386LT31D3+T application, or MAX6386LT31D3+T equivalent, key selection criteria include its 3.08V threshold accuracy, 140ms reset timeout, MR input compatibility with TTL/CMOS logic, guaranteed reset validity down to 1V supply, and SC70-4 package footprint for space-constrained embedded designs.

Technical Context

The MAX6386LT31D3+T implements a precision bandgap-based voltage comparator monitoring VCC against a fixed 3.08V threshold, with ±2.5% tolerance across –40°C to +125°C and 60ppm/°C tempco. Its internal timer initiates a 140ms minimum reset assertion after VCC recovers above threshold.

It integrates a debounced manual reset input (MR) with 1µs minimum pulse width support and 100ns glitch rejection; MR asserts reset when pulled low and holds reset active for the full 140ms timeout after release. The open-drain RESET output requires an external pullup and sinks up to 3.2mA at VCC ≥ 4.5V with VOL ≤ 0.4V.

Key Specifications

Pinout & Package

MAX6386LT31D3+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 2.0mm × 2.1mm × 0.95mm, with thermal resistance θJA = 322.6°C/W on multilayer board.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6386LT31D3+T, MAX6326XR31D3+T simplifies design by removing the external pullup requirement but lacks MR functionality, while TPS3808G33DBVR offers tighter threshold tolerance at the cost of higher quiescent current and no integrated manual reset - making MAX6386LT31D3+T optimal for space- and power-constrained systems needing both precise threshold and pushbutton reset.

Availability

MAX6386LT31D3+T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive body control units, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6386LT31D3+T 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, automotive, and computing markets.

The MAX6381–MAX6390 family delivers ultra-low-power, factory-trimmed reset supervision for battery-operated and thermally demanding systems, with variants optimized for single/dual supply monitoring, manual reset integration, and AEC-Q100 compliance.

FAQ

What is the exact reset threshold voltage of MAX6386LT31D3+T and how stable is it over temperature?

The MAX6386LT31D3+T has a factory-set nominal reset threshold of 3.08V, with guaranteed limits of 3.00V (min) and 3.15V (max) at +25°C. Over the full operating range of –40°C to +125°C, the threshold remains within ±2.5% of nominal (2.99V to 3.17V), with a tempco of 60ppm/°C. This stability ensures consistent brownout detection across automotive and industrial environments without external calibration.

Does MAX6386LT31D3+T require an external pullup resistor on the RESET pin?

Yes, MAX6386LT31D3+T features an open-drain active-low RESET output and requires an external pullup resistor to the host supply rail (e.g., 3.3V or 5V). Typical values range from 4.7kΩ to 10kΩ. This configuration enables wired-OR reset buses and level-shifting flexibility - unlike push-pull variants such as MAX6326XR31D3+T, which do not require external pullups.

What is the function and electrical behavior of the MR pin on MAX6386LT31D3+T?

The MR (Manual Reset) pin on MAX6386LT31D3+T is an active-low input with an internal 63kΩ pullup resistor to VCC. Driving MR low forces an immediate reset assertion, which remains active for the full 140ms timeout after MR is released. It accepts TTL/CMOS logic levels, supports 1µs minimum pulse width, and rejects 100ns glitches - enabling direct connection to momentary switches or digital outputs without external debounce circuitry.

Can MAX6386LT31D3+T operate reliably at VCC = 1.2V, and what happens to the RESET output below 1.8V?

Yes, MAX6386LT31D3+T is fully specified to operate down to VCC = 1.0V, and its RESET output state remains guaranteed valid across this entire range. At VCC = 1.2V, the open-drain RESET can still sink 80µA with VOL ≤ 0.3V (per datasheet), ensuring compatible logic levels with 1.2V/1.8V I/O standards. Below 1.8V, supply current drops to ~4μA, preserving battery life without compromising reset integrity.

Is MAX6386LT31D3+T pin-compatible with legacy Maxim reset ICs like MAX809 or MAX6346?

No, MAX6386LT31D3+T is not pin-compatible with MAX809 (3-pin SOT23) or MAX6346 (3-pin SOT23), as it uses a 4-pin SC70 package with dedicated MR and GND pins. However, it is functionally and footprint-compatible with other 4-pin SC70 variants in the MAX6384–MAX6390 family (e.g., MAX6384XS31D3+T), sharing identical pinout, thermal profile, and land pattern (90-0187).