Analog Devices Inc./Maxim Integrated MAX6388XS21D4-T

Overview

MAX6388XS21D4-T from Maxim Integrated is a low-power microprocessor supervisory circuit with active-high push-pull reset output, factory-set 2.10V VCC reset threshold (±2.5% over –40°C to +125°C), 1120ms minimum VCC reset timeout, and auxiliary RESET IN input for dual-voltage monitoring. It operates from 1.0V to 5.5V supply and consumes only 3μA at 1.8V, targeting power-critical embedded systems requiring reliable brownout detection.

For engineers reviewing the MAX6388XS21D4-T datasheet, MAX6388XS21D4-T pinout, MAX6388XS21D4-T application, or MAX6388XS21D4-T equivalent, key selection criteria include its 2.10V reset threshold accuracy, 1120ms VCC timeout, 4-pin SC70 package footprint, RESET IN comparator compatibility with external resistor dividers, and guaranteed reset validity down to VCC = 1V.

Technical Context

The MAX6388XS21D4-T integrates a precision bandgap reference and comparator to monitor VCC against a fixed 2.10V threshold while simultaneously accepting an auxiliary voltage via RESET IN, which is compared to an internal 1.27V reference. Its reset assertion logic triggers on either VCC falling below 2.10V or RESET IN falling below its derived threshold.

A dedicated internal timer enforces a minimum 1120ms reset pulse width after VCC recovers above threshold, and the active-high push-pull output drives high during reset-ensuring immediate μP initialization without external pullup. The device guarantees correct output state down to VCC = 1V and exhibits immunity to negative-going VCC transients up to 35µs at 100mV overdrive.

Key Specifications

Pinout & Package

MAX6388XS21D4-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 PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6388XS21D4-T, the μDFN alternative offers identical functionality in a thermally superior but larger package, while the TLV803 variant sacrifices RESET IN capability and threshold accuracy to achieve lower cost and smaller footprint-making MAX6388XS21D4-T optimal for space-constrained dual-rail systems requiring high accuracy and guaranteed 1V operation.

Availability

MAX6388XS21D4-T is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, portable medical monitors, and battery-powered IoT sensor nodes requiring stable component supply, long-term lifecycle support, and AEC-Q100-compliant sourcing.

Supply support for MAX6388XS21D4-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, mixed-signal, and power management ICs for industrial, automotive, communications, and computing markets.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy microprocessor supervisory circuits targeting space- and energy-constrained embedded systems needing dual-voltage monitoring and guaranteed reset behavior across extended temperature ranges.

FAQ

What is the exact reset threshold voltage of MAX6388XS21D4-T and how tightly is it specified?

The MAX6388XS21D4-T has a factory-set reset threshold of 2.10V, 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" and applies directly to the XS21 suffix. The threshold is trimmed at wafer test and does not require external calibration.

Does MAX6388XS21D4-T support monitoring of a second voltage rail, and how is it implemented?

Yes, MAX6388XS21D4-T supports dual-voltage supervision via its dedicated RESET IN pin. This input compares the external voltage to an internal 1.27V reference; users configure the second threshold using a resistor divider network connected to RESET IN. The device asserts reset if either VCC falls below 2.10V or the voltage at RESET IN drops below its derived threshold, enabling flexible dual-rail monitoring without additional ICs.

What is the function and timing behavior of the RESET output on MAX6388XS21D4-T?

The RESET output of MAX6388XS21D4-T is an active-high push-pull driver. It goes high when VCC falls below 2.10V (or RESET IN falls below its threshold), remains high for a minimum of 1120ms after VCC rises above threshold, and returns low thereafter. This behavior is guaranteed down to VCC = 1V, ensuring deterministic reset signaling even during severe brownout conditions.

Is MAX6388XS21D4-T pin-compatible with other members of the MAX6381–MAX6390 family, and what package does it use?

MAX6388XS21D4-T uses a 4-pin SC70 package (outline 21-0098) and is pin-compatible with other 4-pin SC70 variants in the family, including MAX6384–MAX6386 and MAX6387–MAX6390. Pin 1 is VCC, Pin 2 is RESET, Pin 3 is RESET IN, and Pin 4 is GND - consistent across all 4-pin SC70 versions. It is not compatible with 3-pin or 6-pin variants due to differing pin counts and functions.

What are the absolute maximum ratings for VCC and RESET IN on MAX6388XS21D4-T?

The absolute maximum rating for VCC is –0.3V to +6.0V, and for RESET IN it is –0.3V to (VCC + 0.3V). These limits are specified in the Absolute Maximum Ratings table and define the stress boundaries beyond which permanent damage may occur. Operation within these limits ensures long-term reliability, especially during transient events like hot-plug or power sequencing mismatches.