Analog Devices Inc./Maxim Integrated MAX6386XS44D3-T

Overview

MAX6386XS44D3-T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 4.38V 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 controllers and portable instrumentation requiring reliable power-on reset under brownout conditions.

For engineers reviewing the MAX6386XS44D3-T datasheet, MAX6386XS44D3-T pinout, MAX6386XS44D3-T application, or MAX6386XS44D3-T equivalent, key selection criteria include its 4-pin SC70 package, guaranteed reset validity down to VCC = 1V, ±2.5% threshold accuracy over temperature, and compatibility with systems needing manual reset assertion without external debounce circuitry.

Technical Context

The MAX6386XS44D3-T implements a precision bandgap-based reset comparator with 60ppm/°C tempco and guarantees correct reset state for VCC ≥ 1V. Its internal timer enforces a fixed 140ms minimum reset timeout after VCC recovery, independent of supply ramp rate.

It features an active-low manual reset input (MR) with 1µs minimum pulse width support, 100ns glitch rejection, and 200ns MR-to-reset delay - all operating across the full -40°C to +125°C industrial temperature range without external components.

Key Specifications

Pinout & Package

MAX6386XS44D3-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, optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX809TRD3+T, MAX6386XS44D3-T adds manual reset and tighter threshold tolerance; compared with TPS3808G33DBVR, it delivers fixed, production-validated timing with zero external components - simplifying qualification for cost-sensitive industrial designs.

Availability

MAX6386XS44D3-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 product lifecycles.

Supply support for MAX6386XS44D3-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 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 targeting space- and power-constrained embedded systems where deterministic power-on sequencing and field-serviceable reset are critical.

FAQ

What is the exact reset threshold voltage of MAX6386XS44D3-T and how does it vary with temperature?

The MAX6386XS44D3-T has a nominal reset threshold of 4.38V, with a guaranteed range of 4.27V to 4.48V at +25°C. Over the full operating temperature range of -40°C to +125°C, the threshold remains within ±2.5% of nominal (4.27V to 4.48V), with a tempco of 60ppm/°C. This specification is validated per the manufacturer's electrical characteristics table and ensures predictable brownout detection in automotive and industrial environments where supply rails drift with temperature.

Does MAX6386XS44D3-T require an external pullup resistor on the RESET pin, and what value is recommended?

Yes, MAX6386XS44D3-T requires an external pullup resistor on the open-drain RESET pin because it cannot drive high actively. A value between 10kΩ and 100kΩ is recommended, selected based on bus capacitance and rise-time requirements. For typical 3.3V systems with ≤50pF load, 47kΩ provides reliable rise time (<1µs) while minimizing quiescent current. The pullup must connect to the same supply rail as the host microcontroller's reset input to ensure valid logic levels.

Can MAX6386XS44D3-T operate reliably when VCC drops below 1.8V, and down to what minimum voltage does it guarantee correct reset behavior?

Yes, MAX6386XS44D3-T operates reliably down to VCC = 1.0V and guarantees correct reset output state (valid logic level) for VCC ≥ 1.0V. This is explicitly specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Below 1.0V, reset behavior is not guaranteed - however, the device continues to draw only ~1µA, enabling graceful shutdown in ultra-low-power systems. This feature is critical for battery-powered devices experiencing deep brownout.

What is the function of the MR pin on MAX6386XS44D3-T, and does it need an external pullup resistor?

The MR pin on MAX6386XS44D3-T is an active-low manual reset input with an internal 63kΩ pullup resistor to VCC, so no external pullup is required. Driving MR low (≤0.3×VCC) forces reset assertion for the full 140ms timeout period, even if VCC remains above threshold. When unused, MR may be left floating or tied to VCC. The internal pullup ensures defined logic state and eliminates BOM cost - a key differentiator versus alternatives like the MAX809 series.

Is MAX6386XS44D3-T pin-compatible with any legacy Maxim reset ICs, and which ones share the same 4-pin SC70 footprint?

MAX6386XS44D3-T shares the identical 4-pin SC70 package (outline 21-0098) and pinout with other members of the MAX6384–MAX6390 family, including MAX6384XSxxDx-T and MAX6385XSxxDx-T. It is not pin-compatible with 3-pin SC70 parts (e.g., MAX809) or 6-pin µDFN variants. The pin mapping - VCC (1), RESET (2), MR (3), GND (4) - is consistent across all 4-pin SC70 versions, enabling direct substitution within the same family when reset threshold and timeout match design requirements.