Analog Devices Inc./Maxim Integrated MAX6386XS46D1+

Overview

MAX6386XS46D1+ from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 4.63V reset threshold (±2.5% over -40°C to +125°C), and 140ms minimum reset timeout. It monitors VCC from +1.8V to +5.0V while consuming only 3μA at +1.8V, and features a debounced manual reset input (MR) with internal 63kΩ pullup - used in battery-powered controllers and critical μP power-up sequencing.

For engineers reviewing the MAX6386XS46D1+ datasheet, MAX6386XS46D1+ pinout, MAX6386XS46D1+ application, or MAX6386XS46D1+ equivalent, key selection criteria include its 4-pin SC70 package, guaranteed reset validity down to VCC = 1V, open-drain output requiring external pullup, and compatibility with dual-voltage monitoring systems where MR-initiated resets must coexist with VCC brownout detection.

Technical Context

This device implements a precision voltage comparator with ±2.5% threshold accuracy across -40°C to +125°C and a temperature-compensated internal reference (60ppm/°C tempco). Its reset assertion logic responds to either VCC falling below 4.63V or MR pulled low, with independent timing control: VCC-triggered reset remains asserted for ≥140ms after recovery, while MR-triggered reset follows the same timeout due to shared tRP configuration.

The open-drain RESET output supports level-shifting and wired-OR configurations, sinking up to 3.2mA at VCC ≥ 4.5V (VOL ≤ 0.4V), and exhibits negative-going VCC transient immunity validated up to 35µs at 100mV overdrive - critical for noisy industrial power rails.

Key Specifications

Pinout & Package

MAX6386XS46D1+ uses a 4-pin SC70 package (2.0mm × 2.1mm footprint) with exposed pad for thermal performance. Pin 1 = VCC, Pin 2 = RESET (open-drain active-low), Pin 3 = MR (active-low manual reset), Pin 4 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326XR46D3+ and TPS3808G33DBVR, MAX6386XS46D1+ uniquely combines 5V-system-optimized threshold, MR functionality, and open-drain flexibility - making it the sole option among the three for space-constrained 5V controllers requiring field-serviceable reset capability.

Availability

MAX6386XS46D1+ is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered data loggers, medical infusion pumps, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for MAX6386XS46D1+ 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 medical applications, with expertise in low-power supervision and robust interface solutions.

The MAX6381–MAX6390 family delivers single/dual-voltage microprocessor reset circuits optimized for ultra-low ICC (3–6μA), wide temperature operation (-40°C to +125°C), and AEC-Q100 qualified variants - targeting safety-critical embedded systems where power integrity is non-negotiable.

FAQ

What is the exact reset threshold voltage of MAX6386XS46D1+ and how accurate is it over temperature?

The MAX6386XS46D1+ has a factory-set nominal reset threshold of 4.63V, with guaranteed accuracy of ±2.5% over the full operating temperature range of -40°C to +125°C. This specification is confirmed in the Electrical Characteristics table under "VCC Reset Threshold (VTH)" and applies to all units regardless of batch or date code. The 46 suffix in the part number explicitly denotes the 4.63V threshold variant, and the ±2.5% tolerance ensures reliable operation in automotive and industrial environments where voltage rails fluctuate with temperature.

Does MAX6386XS46D1+ require an external pullup resistor on the RESET pin, and why?

Yes, MAX6386XS46D1+ requires an external pullup resistor on the RESET pin because it features an open-drain active-low output. The internal circuitry can only sink current (pull low) but cannot source current to drive high. Without a pullup, the RESET line would float undefined when not asserted. Typical values range from 10kΩ to 100kΩ, selected based on rise time requirements and bus loading - a 47kΩ resistor is commonly used for 3.3V systems. This architecture enables wired-OR reset busing and voltage-level translation, which is essential in multi-supervisor designs.

What is the function of the MR pin on MAX6386XS46D1+, and does it need external components?

The MR (Manual Reset) pin on MAX6386XS46D1+ is an active-low input that forces a reset when pulled to GND, independent of VCC level. It includes an internal 63kΩ pullup resistor to VCC, so no external pullup is needed. A normally open momentary switch between MR and GND suffices for manual reset functionality. For noise immunity in electrically harsh environments, a 0.1μF capacitor from MR to GND is recommended - but no series resistor or debounce logic is required, as internal circuitry handles debouncing automatically.

Can MAX6386XS46D1+ operate reliably when VCC drops below 1.8V, and what is its minimum functional voltage?

Yes, MAX6386XS46D1+ is guaranteed to operate correctly down to VCC = 1.0V, with reset output state validity maintained throughout this range. The datasheet specifies "Reset Output State Guaranteed Valid Down to VCC = 1V", meaning the open-drain RESET pin will correctly assert low during brownout and deassert high after recovery even as VCC collapses to 1V. Below 1V, the device ceases functional operation, but the 1V guarantee exceeds most μP reset requirements and supports graceful shutdown in battery-depleted scenarios.

Is MAX6386XS46D1+ pin-compatible with older Maxim reset ICs like MAX809, and what are the implications?

MAX6386XS46D1+ is pin-compatible with MAX809/MAX810/MAX803 in the 3-pin SC70 package, but not in its native 4-pin SC70 configuration. The 4-pin layout adds the MR function absent in MAX809, so direct replacement requires PCB modification. However, the electrical interface (VCC, GND, RESET) matches, and the reset behavior (open-drain active-low, 4.63V threshold, 140ms timeout) is functionally aligned - enabling drop-in substitution in systems where MR is unused or implemented externally, provided the fourth pin is left unconnected or tied appropriately.