Analog Devices Inc./Maxim Integrated MAX6387XS22D3+

Overview

MAX6387XS22D3+ from Maxim Integrated is a low-power, dual-voltage microprocessor supervisory circuit with active-low push-pull reset output, factory-set 2.19V VCC reset threshold (±2.5% over -40°C to +125°C), 140ms minimum reset timeout, and auxiliary RESET IN input for monitoring a second voltage source. It operates from 1.0V to 5.5V supply and consumes only 3µA at +1.8V, targeting power-sensitive embedded systems requiring reliable brownout detection.

For engineers reviewing the MAX6387XS22D3+ datasheet, MAX6387XS22D3+ pinout, MAX6387XS22D3+ application, or MAX6387XS22D3+ equivalent, this page delivers verified specifications, SC70-4 package layout, dual-supply monitoring capability, reset timing accuracy, and real-world substitution guidance - all grounded in Maxim's official documentation.

Technical Context

The MAX6387XS22D3+ integrates two independent voltage comparators: one monitors VCC against a precision 2.19V internal threshold, while the second compares an external voltage applied to RESET IN against a stable +1.27V reference. Reset assertion occurs if either comparator detects an undervoltage condition, and the internal timer guarantees a minimum 140ms reset pulse width after recovery.

Its 4-pin SC70 package supports compact PCB layouts, and the push-pull active-low RESET output drives directly into µP reset inputs without external pull-up components. The device maintains valid logic states down to VCC = 1.0V and provides immunity to negative-going VCC transients up to 35µs at 100mV overdrive.

Key Specifications

Pinout & Package

MAX6387XS22D3+ uses a 4-pin SC70 package (package code X4-1), measuring 1.25mm × 1.0mm × 0.55mm, suitable for space-constrained applications including wearables and sensor modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6387XS22D3+, the LT22D3+ offers identical functionality in a thermally superior µDFN package, while TPS3808G125DBVR trades dual-supply capability for lower current consumption - making MAX6387XS22D3+ the optimal choice when RESET IN functionality and SC70 size are required.

Availability

MAX6387XS22D3+ is available at Aetrix Electronics and suitable for industrial control systems, medical wearables, automotive body electronics, and smart metering applications requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6387XS22D3+ 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, medical, and communications applications, emphasizing low power, high reliability, and small form factors.

The MAX6381–MAX6390 family was engineered specifically for low-voltage microprocessor supervision in space- and power-constrained systems, delivering dual-rail monitoring, factory-trimmed thresholds, and industry-leading quiescent current in sub-1mm packages.

FAQ

What is the exact reset threshold voltage of MAX6387XS22D3+ and how stable is it over temperature?

The MAX6387XS22D3+ has a factory-set VCC reset threshold of 2.19V (nominal), with guaranteed accuracy of ±2.5% across the full operating temperature range of -40°C to +125°C. This stability is achieved through laser-trimming during production and on-chip temperature compensation, ensuring reliable brownout detection without external calibration.

Does MAX6387XS22D3+ support monitoring of a second voltage, and how is it implemented?

Yes, MAX6387XS22D3+ includes a dedicated RESET IN pin that connects to an internal +1.27V reference comparator. To monitor a second voltage, apply the target supply to RESET IN through a resistor divider network - the threshold is set by V_TH = 1.27V × (R1/R2 + 1), enabling precise, user-adjustable dual-supply supervision without additional ICs.

What is the function of the RESET output on MAX6387XS22D3+, and does it require an external pull-up resistor?

The RESET output of MAX6387XS22D3+ is an active-low push-pull driver, meaning it actively drives low during reset and high when deasserted. Because it is not open-drain, no external pull-up resistor is required - simplifying layout and reducing component count compared to open-drain alternatives like MAX6389.

What is the minimum reset timeout period specified for MAX6387XS22D3+, and is it guaranteed over temperature?

MAX6387XS22D3+ provides a minimum reset timeout period of 140ms, as indicated by the "D3" suffix. This value is guaranteed over the full -40°C to +125°C operating temperature range and is internally generated by a precision RC oscillator, eliminating dependence on external timing components.

Can MAX6387XS22D3+ operate reliably at very low supply voltages, and what is its functional lower limit?

Yes, MAX6387XS22D3+ is guaranteed to maintain valid RESET output logic states down to VCC = 1.0V. Below this level, internal circuitry may cease operation, but the device remains functional throughout the entire specified 1.0V to 5.5V operating range - critical for applications involving deep brownout recovery or ultra-low-power wake-up sequences.