Analog Devices Inc./Maxim Integrated MAX6386XS23D2+T

Overview

MAX6386XS23D2+T from Maxim Integrated is a low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-set 2.31V reset threshold (±2.5% over –40°C to +125°C), 20ms minimum reset timeout, and debounced manual reset input. It monitors VCC from +1.8V to +5.0V while consuming only 3μA at +1.8V and guarantees valid reset state down to VCC = 1V - used in portable battery-powered equipment for reliable power-up sequencing.

For engineers reviewing the MAX6386XS23D2+T datasheet, MAX6386XS23D2+T pinout, MAX6386XS23D2+T application, or MAX6386XS23D2+T equivalent, key selection considerations include its 4-pin SC70 package, 2.31V threshold accuracy, 20ms VCC reset timeout, MR input with internal 63kΩ pullup, and immunity to negative-going VCC transients up to 35µs at 100mV overdrive.

Technical Context

The MAX6386XS23D2+T implements a precision bandgap-based voltage comparator with ±2.5% threshold accuracy across –40°C to +125°C and 60ppm/°C tempco. Its internal timer generates a guaranteed-minimum 20ms reset assertion after VCC rises above 2.31V or after MR release.

It features an open-drain RESET output requiring external pullup, a debounced active-low MR input with 1µs minimum pulse width and 100ns glitch rejection, and operates with valid logic states down to VCC = 1V - enabling robust brownout detection in ultra-low-voltage embedded systems.

Key Specifications

Pinout & Package

MAX6386XS23D2+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 θ_JA = 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 MAX809S23D2+T and TPS3808G23DBVR, the MAX6386XS23D2+T uniquely combines 2.31V threshold accuracy, 20ms timeout, open-drain output, and integrated MR input in a 4-pin SC70 - making it optimal for space-constrained, manually serviceable battery-powered systems requiring flexible reset bus topology.

Availability

MAX6386XS23D2+T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered data loggers, industrial handheld terminals, and smart metering modules requiring stable component supply and long-term lifecycle support.

Supply support for MAX6386XS23D2+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, communications, and computing applications.

The MAX6381–MAX6390 family delivers low-power, high-accuracy μP reset supervision for battery-sensitive and thermally demanding environments - targeting portable instrumentation, critical embedded controllers, and dual-rail power systems.

FAQ

What is the exact reset threshold voltage of the MAX6386XS23D2+T and how stable is it over temperature?

The MAX6386XS23D2+T has a factory-set nominal reset threshold of 2.31V, with guaranteed accuracy of ±2.5% over the full operating temperature range of –40°C to +125°C. Its temperature coefficient is 60ppm/°C, meaning the threshold drifts less than 15mV across the entire range - sufficient for stable operation in automotive under-hood or industrial control cabinet environments. This specification is confirmed in the Electrical Characteristics table of the MAX6381–MAX6390 datasheet.

Does the MAX6386XS23D2+T require an external pullup resistor on the RESET pin, and why?

Yes, the MAX6386XS23D2+T requires an external pullup resistor on the RESET pin because it features an open-drain active-low output. Without a pullup, the RESET line would float high and fail to assert a valid logic low during reset events. A typical value is 10kΩ to the host VCC rail, selected to ensure VOL ≤ 0.3V at ISINK = 1.2mA (per datasheet specs). This architecture enables wired-OR connection with other open-drain reset sources on the same bus.

What is the function and electrical behavior of the MR pin on the MAX6386XS23D2+T?

The MR (Manual Reset) pin on the MAX6386XS23D2+T is an active-low input with internal 63kΩ pullup to VCC. Driving MR low forces immediate reset assertion, which remains active for the full 20ms timeout after MR is released. It accepts TTL/CMOS logic levels, rejects <100ns glitches, and requires ≥1µs minimum pulse width. If unused, MR may be left floating (due to internal pullup) or tied to VCC - no external components are needed unless noise immunity is required.

Can the MAX6386XS23D2+T operate reliably at VCC = 1.2V, and what happens to the RESET output below 1.8V?

Yes, the MAX6386XS23D2+T is fully specified to operate down to VCC = 1.0V, and its RESET output state is guaranteed valid at all VCC levels ≥1.0V. At VCC = 1.2V, the open-drain RESET output can still sink ≥80µA while maintaining VOL ≤ 0.3V, ensuring compatibility with 1.2V logic families. Below 1.0V, the device ceases functional operation - but this is outside the absolute minimum rating, so operation below 1.0V is not supported.

How does the MAX6386XS23D2+T handle short negative transients on the VCC line?

The MAX6386XS23D2+T provides built-in immunity to short negative-going VCC transients: it will not issue a spurious reset for glitches ≤35µs wide when the overdrive (VTH – VCC) is 100mV, per the "Maximum Transient Duration vs. Reset Comparator Overdrive" graph in the datasheet. This feature reduces sensitivity to switching noise or coupling from adjacent circuits, eliminating the need for additional RC filtering in many compact PCB layouts - though a 0.1µF ceramic capacitor placed close to the VCC pin is still recommended for best practice.