Analog Devices Inc./Maxim Integrated MAX6387XS29D2

Overview

MAX6387XS29D2 from Maxim Integrated is a low-power, dual-voltage microprocessor supervisory circuit with active-low push-pull reset output, factory-set 2.93V 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 MAX6387XS29D2 datasheet, MAX6387XS29D2 pinout, MAX6387XS29D2 application, or MAX6387XS29D2 equivalent, key selection criteria include its dual-monitoring capability (VCC + RESET IN), guaranteed reset validity down to VCC = 1V, ±2.5% threshold accuracy over temperature, and SC70-4 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX6387XS29D2 integrates two independent voltage comparators: one monitors VCC against a fixed 2.93V threshold, while the other compares an external voltage applied to the RESET IN pin against an internal +1.27V reference. Its reset assertion logic triggers when either monitored voltage falls below its respective threshold, and the active-low push-pull output remains asserted for a guaranteed minimum 140ms after recovery.

It features negative-going VCC transient immunity up to ~35µs for 100mV overdrive, supports manual reset via external signal only in related variants (not this part), and guarantees valid reset state down to VCC = 1V-enabling robust operation during deep brownout conditions without external pull resistors.

Key Specifications

Pinout & Package

MAX6387XS29D2 is housed in a 4-pin SC70 package (package code X4-1), measuring 1.5mm × 1.0mm × 0.8mm, with wettable flank leads for automated optical inspection (AOI) and high-yield reflow soldering.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6387XS29D2, the LT29D2 variant offers identical functionality in a thermally superior µDFN package, while the TPS3808G125DBVR provides tighter initial accuracy but omits the critical RESET IN feature and requires external biasing-making it unsuitable for dual-supply coordination.

Availability

MAX6387XS29D2 is available at Aetrix Electronics and suitable for industrial PLC I/O modules, automotive body control units, medical wearable sensors, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6387XS29D2 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and communications markets.

The MAX6381–MAX6390 family was designed specifically for low-power, dual-voltage microprocessor supervision in space- and energy-constrained embedded systems, emphasizing accuracy, small footprint, and robust transient immunity.

FAQ

What is the exact reset threshold voltage of MAX6387XS29D2?

The MAX6387XS29D2 has a factory-set VCC reset threshold of 2.93V, with guaranteed limits of 2.85V (minimum) and 3.00V (maximum) across –40°C to +125°C. This value is laser-trimmed during production and specified in the Reset Thresholds table of the datasheet. The '29' suffix in MAX6387XS29D2 explicitly denotes this 2.93V threshold point.

Does MAX6387XS29D2 support manual reset functionality?

No, MAX6387XS29D2 does not include a manual reset (MR) input. According to the Selector Guide and Pin Description tables, MR is present only on MAX6384/MAX6385/MAX6386/MAX6390 variants. MAX6387XS29D2 features RESET IN instead-dedicated to monitoring a second voltage-and lacks MR pin functionality entirely.

What is the purpose of the RESET IN pin on MAX6387XS29D2?

The RESET IN pin on MAX6387XS29D2 connects to an internal +1.27V reference comparator, enabling supervision of a secondary voltage rail. By applying a resistor divider to RESET IN, users can configure a custom reset threshold using the formula V_INTH = 1.27V × (R1/R2 + 1). This allows coordinated reset assertion when either VCC or the auxiliary supply fails.

What package type and dimensions does MAX6387XS29D2 use?

MAX6387XS29D2 uses a 4-pin SC70 package (package code X4-1), with nominal dimensions of 1.5mm × 1.0mm × 0.8mm and wettable flank leads. This compact outline is documented in Maxim's package drawing 21-0098 and supports high-density PCB layouts typical in portable and automotive electronics.

How does MAX6387XS29D2 handle power supply transients?

MAX6387XS29D2 provides inherent immunity to short negative-going VCC transients: it will not assert reset for glitches ≤35µs wide when the overdrive (V_TH – V_CC) is 100mV. This behavior is characterized in the Typical Operating Characteristics graph "Maximum Transient Duration vs. Reset Comparator Overdrive" and enhances reliability in electrically noisy environments without requiring additional filtering.