Analog Devices Inc./Maxim Integrated MAX6386LT29D3+T

Overview

MAX6386LT29D3+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 2.93V reset threshold (±2.5% over -40°C to +125°C), 140ms minimum VCC reset timeout, and debounced manual reset input (MR) with internal 63kΩ pullup. It monitors single supply voltage in battery-powered embedded systems requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6386LT29D3+T datasheet, MAX6386LT29D3+T pinout, MAX6386LT29D3+T application, or MAX6386LT29D3+T equivalent, key selection criteria include its 2.93V threshold accuracy, 140ms reset hold time, MR input compatibility with TTL/CMOS logic, guaranteed valid reset down to VCC = 1V, and 4-pin SC70 package footprint for space-constrained designs.

Technical Context

The MAX6386LT29D3+T implements a precision bandgap-based voltage comparator with ±2.5% threshold tolerance over full industrial temperature range (-40°C to +125°C) and 60ppm/°C tempco. Its internal timer generates a fixed 140ms minimum reset assertion period after VCC rises above 2.93V or after MR release.

It features an open-drain RESET output requiring external pullup, a debounced MR input tolerant of noise (100ns glitch rejection), and guaranteed operation down to VCC = 1V - enabling robust reset signaling during deep brownout conditions without external support circuitry.

Key Specifications

Pinout & Package

MAX6386LT29D3+T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098, land pattern 90-0187), measuring 1.25mm × 1.25mm × 0.95mm, suitable for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6386LT29D3+T, MAX6326XR29D3+T simplifies layout by removing the pullup resistor but sacrifices bus-sharing capability, while TPS3808G33DBVR offers higher precision and broader voltage support at the cost of footprint size and loss of MR functionality - making MAX6386LT29D3+T optimal for compact, MR-dependent, multi-device reset networks.

Availability

MAX6386LT29D3+T is available at Aetrix Electronics and suitable for portable instrumentation, industrial controllers, test equipment, and battery-powered microcontroller systems requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6386LT29D3+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 demanding industrial, automotive, and computing applications, with emphasis on low-power, high-reliability solutions.

The MAX6381–MAX6390 family delivers ultra-low-power microprocessor supervisory circuits optimized for space-constrained, battery-sensitive, and thermally harsh environments - targeting portable medical devices, smart sensors, and ruggedized control modules.

FAQ

What is the exact reset threshold voltage of the MAX6386LT29D3+T and how stable is it over temperature?

The MAX6386LT29D3+T has a nominal reset threshold of 2.93V, with guaranteed tolerance of ±2.5% across the full operating temperature range of -40°C to +125°C. Its temperature coefficient is 60ppm/°C, meaning threshold drift is limited to approximately ±15mV over the entire range - sufficient for stable operation in automotive under-hood and industrial control cabinet environments. This specification is confirmed in the Electrical Characteristics table of the official datasheet.

Does the MAX6386LT29D3+T require an external pullup resistor on the RESET pin?

Yes, the MAX6386LT29D3+T features an open-drain active-low RESET output, which requires an external pullup resistor to the appropriate logic rail (e.g., 3.3V or 5V). The datasheet specifies that the output can sink up to 3.2mA when asserted at VCC ≥ 4.5V, so a typical 10kΩ pullup provides adequate rise time while limiting current. This architecture enables wired-OR reset bus configurations not possible with push-pull outputs.

What is the function and electrical behavior of the MR pin on the MAX6386LT29D3+T?

The MR (Manual Reset) pin on the MAX6386LT29D3+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 returns high. It accepts TTL/CMOS logic levels and rejects glitches shorter than 100ns. No external components are needed - a simple momentary switch from MR to GND suffices for field-serviceable reset functionality.

Can the MAX6386LT29D3+T operate reliably when VCC drops below 2.0V?

Yes, the MAX6386LT29D3+T guarantees correct RESET output logic state down to VCC = 1.0V, per Absolute Maximum Ratings and Electrical Characteristics. Its internal comparator and timer remain functional throughout this range, ensuring deterministic reset assertion during deep brownout events. However, note that the open-drain RESET output requires an external pullup referenced to a stable rail - the pullup voltage source must remain valid for the output to drive correctly.

What package type and dimensions does the MAX6386LT29D3+T use, and is it RoHS-compliant?

The MAX6386LT29D3+T uses a 4-pin SC70 package (outline 21-0098), measuring 1.25mm × 1.25mm × 0.95mm with 0.65mm pin pitch. It is RoHS-compliant and lead-free, indicated by the "+T" suffix in the part number. This ultra-compact footprint supports high-density PCB layouts in portable and wearable electronics where board space is at a premium.