Analog Devices Inc./Maxim Integrated MAX6386XS45D3+T

Overview

MAX6386XS45D3+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 4.50V 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 systems in battery-powered instrumentation and embedded controllers requiring reliable power-on reset under brownout conditions.

For engineers reviewing the MAX6386XS45D3+T datasheet, MAX6386XS45D3+T pinout, MAX6386XS45D3+T application, or MAX6386XS45D3+T equivalent, key selection criteria include its 4-pin SC70 package, guaranteed reset validity down to VCC = 1V, ±2.5% threshold accuracy across automotive temperature range, and compatibility with dual-voltage monitoring architectures via external resistor networks.

Technical Context

The MAX6386XS45D3+T implements a precision bandgap-based voltage comparator for VCC monitoring and an independent MR input with glitch rejection (100ns) and 1µs minimum pulse width support. Its internal timer ensures deterministic 140ms reset assertion after VCC recovery or MR release.

As an open-drain device, it requires an external pullup resistor on RESET; output leakage remains ≤1.0µA when deasserted, and VOL ≤0.3V at ISINK = 1.2mA (VCC ≥ 2.5V). The MR pin's internal 63kΩ pullup enables direct switch-to-GND connection without external biasing.

Key Specifications

Pinout & Package

MAX6386XS45D3+T uses a 4-pin SC70 package (outline 21-0098, land pattern 90-0187) with exposed pad not electrically connected. Pin 1 is VCC, Pin 2 is RESET (open-drain active-low), Pin 3 is MR (active-low manual reset), and Pin 4 is GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6386XS45D3+T, the LT45D3 variant offers identical functionality in a larger package with worse thermal performance, while TPS3808G33DBVR sacrifices MR and open-drain versatility for simplified 3.3V-only use cases - neither provides drop-in replacement capability without layout or firmware changes.

Availability

MAX6386XS45D3+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 MAX6386XS45D3+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 single/dual low-voltage microprocessor reset circuits optimized for battery-powered and automotive systems where supply stability, timing predictability, and small footprint are critical.

FAQ

What is the exact reset threshold voltage of MAX6386XS45D3+T and how does it vary with temperature?

The MAX6386XS45D3+T has a factory-set nominal reset threshold of 4.50V, with guaranteed tolerance of ±2.5% over the full operating temperature range of -40°C to +125°C. This means the actual threshold falls between 4.39V and 4.61V at any temperature within that range. The tempco is specified at 60ppm/°C, contributing to predictable drift behavior in thermally dynamic environments.

Does MAX6386XS45D3+T require an external pullup resistor on the RESET pin, and what value is recommended?

Yes, MAX6386XS45D3+T features an open-drain active-low RESET output and requires an external pullup resistor. A value between 10kΩ and 100kΩ is typical; 47kΩ is commonly used to balance rise time (with RESET capacitance) against power consumption. The resistor connects between RESET and the target logic rail (e.g., 3.3V or 5V), enabling level translation and wired-OR configurations.

Can MAX6386XS45D3+T monitor a second voltage rail, and if not, what alternatives exist in the same family?

No, MAX6386XS45D3+T does not support auxiliary voltage monitoring - it monitors only VCC. For dual-rail supervision, consider MAX6387XS45D3+T (same threshold/timing, adds RESET IN pin) or MAX6389XS45D3+T (identical features with AEC-Q100 qualification). Both share the same 4-pin SC70 package and pinout compatibility except for the added RESET IN function.

What is the minimum VCC voltage at which MAX6386XS45D3+T guarantees correct RESET output logic state?

MAX6386XS45D3+T guarantees valid RESET output logic state down to VCC = 1.0V. Below this, the internal circuitry cannot maintain defined behavior. This feature ensures reliable reset assertion during deep brownout events common in battery-depleted systems, unlike many competitors that cease operation above 1.5V.

Is MAX6386XS45D3+T pin-compatible with legacy Maxim reset ICs like MAX809 or MAX6326?

MAX6386XS45D3+T is not pin-compatible with MAX809 (3-pin SOT23) or MAX6326 (3-pin SOT23), as it uses a 4-pin SC70 package with different pin assignment (VCC, RESET, MR, GND). However, it is functionally compatible and listed as pin-compatible with other 4-pin SC70 variants in the MAX6384–MAX6390 series, such as MAX6384XS45D3+T (push-pull variant) and MAX6385XS45D3+T (active-high push-pull).