Analog Devices Inc./Maxim Integrated MAX6385XS37D5-T

Overview

MAX6385XS37D5-T from Maxim Integrated is a precision microprocessor supervisory circuit with active-high push-pull reset output, factory-set 3.70V reset threshold (±2.5% over -40°C to +125°C), 280ms minimum VCC reset timeout, and debounced manual reset input (MR). It monitors single-supply rails in low-power embedded systems, ensuring reliable μP initialization during power-up, brownout, or transient events. Designed for 1.8V–5.0V operation, it draws only 3μA at 1.8V.

For engineers reviewing the MAX6385XS37D5-T datasheet, MAX6385XS37D5-T pinout, MAX6385XS37D5-T application, or MAX6385XS37D5-T equivalent, key selection criteria include reset threshold accuracy, MR timing behavior, push-pull output drive capability down to VCC = 1V, and compatibility with SC70-4 packaging for space-constrained PCB layouts.

Technical Context

The MAX6385XS37D5-T implements a precision bandgap-based voltage comparator with ±2.5% threshold tolerance over full temperature range, paired with a digitally controlled monostable timer for deterministic 280ms reset assertion after VCC recovery. Its internal 63kΩ MR pullup resistor enables direct connection of a momentary switch to GND without external components.

Unlike open-drain variants, this device delivers active-high push-pull RESET output capable of sourcing 800µA at VCC ≥ 4.5V while maintaining VOH ≥ 0.8×VCC - eliminating need for external pullups and supporting direct interface to CMOS/TTL inputs. Reset state remains valid down to VCC = 1V, enabling robust operation during deep brownout conditions.

Key Specifications

Pinout & Package

MAX6385XS37D5-T is housed in a RoHS-compliant 4-pin SC70 package (outline 21-0098), measuring 2.0mm × 2.1mm × 0.95mm, suitable for high-density PCBs and automated SMT assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6385XS37D5-T, MAX6326XR37D5+T offers identical threshold and timing but inverted logic and no MR, while TPS3123E18DBVR adds watchdog capability at the cost of different threshold and missing MR debounce - making MAX6385XS37D5-T optimal for dedicated, manually controllable 3.3V system supervision.

Availability

MAX6385XS37D5-T is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive telematics units, and smart energy meters requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6385XS37D5-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 demanding industrial, automotive, and medical applications.

The MAX6381–MAX6390 family delivers ultra-low-power, high-accuracy reset supervision for microprocessor-based systems where supply stability, timing predictability, and board space are critical constraints.

FAQ

What is the exact reset threshold voltage of the MAX6385XS37D5-T and how tightly is it specified?

The MAX6385XS37D5-T has a factory-set nominal reset threshold of 3.70V, with guaranteed tolerance of ±2.5% over the full operating temperature range (-40°C to +125°C). This means the actual threshold falls between 3.61V and 3.79V at any temperature within spec, ensuring reliable detection of 3.3V rail faults while accommodating typical supply ripple and aging drift. The MAX6385XS37D5-T achieves this accuracy using laser-trimmed on-chip resistors and a precision bandgap reference.

Does the MAX6385XS37D5-T support manual reset, and how is it implemented?

Yes, the MAX6385XS37D5-T includes a debounced manual reset input (MR) on Pin 3. It features an internal 63kΩ pullup resistor to VCC, allowing direct connection of a normally open momentary switch between MR and GND. When pressed, MR is pulled low, forcing an immediate active-high RESET assertion that persists for the full 280ms timeout after release. No external RC network is required due to built-in digital debouncing. This behavior is confirmed in the MAX6385XS37D5-T datasheet's Pin Description and Detailed Description sections.

What output configuration does the MAX6385XS37D5-T use, and why does it matter for system design?

The MAX6385XS37D5-T uses an active-high push-pull RESET output (Pin 2), meaning it actively drives high during reset and actively pulls low when deasserted. This eliminates the need for an external pullup resistor - unlike open-drain alternatives - simplifying layout, reducing component count, and ensuring fast, clean edges compatible with modern CMOS/TTL inputs. The MAX6385XS37D5-T can source up to 800µA at VCC ≥ 4.5V while maintaining VOH ≥ 0.8×VCC, making it ideal for direct interface to microcontrollers without signal conditioning.

Can the MAX6385XS37D5-T operate reliably during severe supply brownout conditions?

Yes, the MAX6385XS37D5-T guarantees valid RESET output logic states down to VCC = 1.0V, far below its 3.70V reset threshold. This ensures the reset signal remains asserted correctly even as the supply collapses, preventing premature release of the microprocessor before the rail recovers sufficiently. The MAX6385XS37D5-T achieves this through specialized low-voltage biasing and comparator design, as verified in the Electrical Characteristics table and "Ensuring a Valid RESET Output Down to VCC = 0V" application note section.

Is the MAX6385XS37D5-T available in automotive-grade qualification, and what does that entail?

The MAX6385XS37D5-T is offered in an AEC-Q100 qualified version denoted by the /V suffix (e.g., MAX6385XS37D5/V+T), which undergoes rigorous stress testing including temperature cycling, HTOL, and ESD per automotive standards. While the base MAX6385XS37D5-T is rated for -40°C to +125°C operation, the /V variant adds process-level controls, enhanced screening, and certified traceability required for safety-critical automotive subsystems such as telematics and body control modules. This qualification is explicitly stated in the Features and Ordering Information sections of the MAX6385XS37D5-T datasheet.