Analog Devices Inc./Maxim Integrated MAX6385XS17D4-T

Overview

MAX6385XS17D4-T from Maxim Integrated is a precision active-high push-pull μP supervisory circuit designed for reliable power-on reset and brownout detection in low-voltage embedded systems. It features a factory-set 1.67V reset threshold (±2.5% over -40°C to +125°C), 1120ms minimum VCC reset timeout, 3μA supply current at 1.8V, and operates down to VCC = 1.0V. It is used in portable battery-powered equipment requiring stable, low-power reset assertion during voltage transients.

For engineers reviewing the MAX6385XS17D4-T datasheet, MAX6385XS17D4-T pinout, MAX6385XS17D4-T application, or MAX6385XS17D4-T equivalent, key selection criteria include its active-high push-pull output logic, manual reset input with internal pullup, 4-pin SC70 package, and guaranteed reset validity at VCC ≥ 1V - critical for ultra-low-power microcontroller startup sequencing and brownout recovery.

Technical Context

The MAX6385XS17D4-T integrates a precision bandgap-based voltage comparator monitoring VCC against a fixed 1.67V threshold, coupled with a monotonic timeout counter that holds RESET high for ≥1120ms after VCC exceeds the threshold. Its MR input uses an internal 63kΩ pullup resistor and responds to TTL/CMOS-compatible low pulses to force reset, with glitch rejection of 100ns.

This device belongs to the MAX6384–MAX6390 family optimized for single-supply monitoring in space-constrained applications. Unlike open-drain variants, it delivers rail-to-rail active-high push-pull drive without external pullups, enabling direct interface to μP reset inputs requiring asserted-high logic levels - eliminating board-level components and reducing BOM count.

Key Specifications

Pinout & Package

MAX6385XS17D4-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 high-density portable PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6385XS17D3-T and MAX6385LT17D4-T, the MAX6385XS17D4-T uniquely balances ultra-low power consumption, long reset timeout, and minimal footprint - making it optimal for battery-critical, space-constrained applications where extended reset assertion and compact packaging are jointly required.

Availability

MAX6385XS17D4-T is available at Aetrix Electronics and suitable for portable medical sensors, battery-powered IoT nodes, industrial PLC I/O modules, and automotive body control units requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6385XS17D4-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 power, sensing, connectivity, and security applications - serving industrial, automotive, communications, and consumer markets.

The MAX6384–MAX6390 product line delivers ultra-low-power, factory-trimmed supervisory circuits targeting space- and energy-constrained embedded systems requiring deterministic reset behavior across wide temperature ranges.

FAQ

What is the exact reset threshold voltage of MAX6385XS17D4-T and how stable is it over temperature?

The MAX6385XS17D4-T has a factory-set nominal reset threshold of 1.67V, with guaranteed tolerance of ±2.5% over the full operating temperature range of -40°C to +125°C. This stability is achieved through laser-trimmed bandgap references and matched transistor ratios in the BiCMOS process. The MAX6385XS17D4-T maintains this accuracy without external calibration, ensuring consistent brownout detection in automotive and industrial environments where thermal cycling is severe.

Does MAX6385XS17D4-T require an external pullup resistor on the RESET pin?

No, the MAX6385XS17D4-T does not require an external pullup resistor on the RESET pin because it features an active-high push-pull output architecture. Unlike open-drain reset ICs, the MAX6385XS17D4-T actively drives the RESET line high during assertion and low during deassertion, eliminating dependency on external components. This simplifies PCB layout and improves noise immunity in high-density designs where routing space is constrained.

What is the function and electrical behavior of the MR pin on MAX6385XS17D4-T?

The MR (Manual Reset) pin on MAX6385XS17D4-T is an active-low input that forces a reset when pulled below 0.3×VCC. It includes a factory-trimmed 63kΩ internal pullup resistor to VCC, so it can be left unconnected or tied directly to a momentary switch to GND. The MAX6385XS17D4-T guarantees MR glitch rejection of 100ns and specifies a minimum pulse width of 1μs, enabling robust manual intervention even in electrically noisy environments without external debounce circuitry.

Can MAX6385XS17D4-T operate reliably at VCC = 1.2V, and what happens to RESET output below that?

Yes, the MAX6385XS17D4-T is fully specified to operate and guarantee correct RESET logic state down to VCC = 1.0V - meaning it remains functional and deterministic at 1.2V. Below 1.0V, the internal circuitry may cease operation, and RESET output behavior is undefined. For applications requiring valid reset signaling all the way to 0V, external pulldown resistors are recommended only for push-pull variants like the MAX6385XS17D4-T, but this falls outside guaranteed specifications and requires careful validation.

How does the 1120ms reset timeout of MAX6385XS17D4-T compare to other timing options in the MAX6384–MAX6390 family?

The 1120ms reset timeout (denoted by suffix "D4") is one of seven standard delays available in the MAX6384–MAX6390 family, positioned between 560ms (D6) and 1200ms (D7). It provides sufficient hold time for slower microcontrollers, external memory initialization, or regulated power supply settling - especially useful in systems with large bulk capacitance or multi-stage LDOs. The MAX6385XS17D4-T's D4 timing avoids the excessive delay of D7 while ensuring robustness beyond typical 200–500ms requirements seen in Cortex-M0/M3 designs.