Analog Devices Inc./Maxim Integrated MAX6387XS17D3

Overview

MAX6387XS17D3 from Maxim Integrated is a low-power microprocessor supervisory circuit with active-low push-pull reset output, factory-set 1.67V VCC reset threshold (±2.5% over −40°C to +125°C), 140ms minimum reset timeout, and auxiliary RESET IN input for dual-voltage monitoring in portable battery-powered systems.

For engineers reviewing the MAX6387XS17D3 datasheet, MAX6387XS17D3 pinout, MAX6387XS17D3 application, or MAX6387XS17D3 equivalent, this page delivers verified electrical parameters, SC70-4 package mapping, dual-supply monitoring capability, reset timing accuracy, and real-world design implications for brownout immunity and manual reset integration.

Technical Context

The MAX6387XS17D3 integrates two independent voltage comparators: one monitors VCC against a precision 1.67V threshold (±2.5% over temperature), while the second compares an external voltage at RESET IN to a stable 1.27V internal reference. Reset asserts if either comparator trips, and remains asserted for a guaranteed 140ms after recovery.

Its push-pull active-low RESET output drives valid logic states down to VCC = 1.0V, supports sink currents up to 3.2mA at VCC ≥ 4.5V (VOL ≤ 0.4V), and features negative-going VCC transient immunity up to 35µs for 100mV overdrive - critical for noisy power rails in embedded controllers.

Key Specifications

Pinout & Package

MAX6387XS17D3 is housed in a lead-free 4-pin SC70 package (X4-1), measuring 1.0mm × 1.0mm × 0.55mm, optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6387XS17D3, the LT17D3 offers identical supervision performance in a larger, thermally robust package, while the TPS3808G17DBVR trades dual-rail capability for tighter threshold tolerance and open-drain flexibility - neither provides the exact combination of SC70-4 size, push-pull drive, and RESET IN found in MAX6387XS17D3.

Availability

MAX6387XS17D3 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, wearables with PMIC integration, and automotive body control units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6387XS17D3 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 computing applications, with emphasis on low-power, high-reliability solutions.

The MAX6381–MAX6390 family was engineered specifically for space- and power-constrained microprocessor systems needing dual-supply monitoring, factory-trimmed thresholds, and guaranteed reset behavior down to 1.0V VCC - addressing reliability gaps in legacy reset ICs.

FAQ

What is the exact reset threshold voltage of MAX6387XS17D3 and how stable is it over temperature?

The MAX6387XS17D3 has a factory-set VCC reset threshold of 1.67V with ±2.5% accuracy over the full −40°C to +125°C operating range. This stability is achieved via laser-trimmed resistors and a precision bandgap reference, ensuring consistent brownout detection without external calibration. The MAX6387XS17D3 maintains this tolerance across its entire specified temperature range, making it suitable for automotive under-hood and industrial control environments.

Does MAX6387XS17D3 require an external pull-up resistor on the RESET pin?

No, MAX6387XS17D3 does not require an external pull-up resistor because it features an active-low push-pull RESET output. The internal driver actively pulls the line low during reset assertion and actively drives it high when deasserted. This eliminates the need for external components, reduces BOM count, and improves noise immunity compared to open-drain alternatives - a key design advantage of the MAX6387XS17D3.

How is the auxiliary RESET IN input used in MAX6387XS17D3, and what voltage does it monitor?

The RESET IN input of MAX6387XS17D3 compares an external voltage to a precise 1.27V internal reference. To monitor a second supply rail, connect RESET IN to the center node of a resistor divider between that rail and ground. The MAX6387XS17D3 asserts reset if either VCC falls below 1.67V or the voltage at RESET IN drops below 1.27V - enabling true dual-rail supervision with a single IC.

What is the minimum VCC voltage at which MAX6387XS17D3 guarantees correct RESET output logic state?

MAX6387XS17D3 guarantees valid RESET output logic levels down to VCC = 1.0V. Below this, the internal circuitry may not sustain proper biasing, but above 1.0V, the push-pull driver ensures VOL ≤ 0.4V (sink) and VOH ≥ 0.8×VCC (source) across all operating conditions. This feature makes the MAX6387XS17D3 uniquely suited for deep brownout scenarios where other reset ICs fail to assert reliably.

Can MAX6387XS17D3 replace MAX809 or MAX6326 in existing designs?

MAX6387XS17D3 is pin-compatible with MAX809/MAX6326 in SC70-3 packages only for single-supply variants, but MAX6387XS17D3 uses SC70-4 and adds RESET IN functionality. Direct replacement requires PCB modification to accommodate the fourth pin and routing of the auxiliary monitor signal. While functionally superior, the MAX6387XS17D3 is not a drop-in substitute unless the design leverages its dual-supply capability and layout supports the extra pin.