Analog Devices Inc./Maxim Integrated MAX6385XS34D4-T

Overview

MAX6385XS34D4-T from Maxim Integrated is a low-power microprocessor supervisory circuit with active-high push-pull reset output, factory-set 3.40V reset threshold (±2.5% over -40°C to +125°C), and 1120ms minimum VCC reset timeout. It monitors single supply voltage in battery-powered or embedded systems and guarantees valid reset state down to VCC = 1V. Designed for critical μP power-up sequencing in portable instrumentation.

For engineers reviewing the MAX6385XS34D4-T datasheet, MAX6385XS34D4-T pinout, MAX6385XS34D4-T application, or MAX6385XS34D4-T equivalent, key selection criteria include reset threshold accuracy, manual reset input compatibility, push-pull active-high drive capability, and SC70-4 package footprint constraints.

Technical Context

The MAX6385XS34D4-T implements a precision bandgap-based voltage comparator with ±2.5% threshold tolerance over full industrial temperature range and integrates a monolithic timer for fixed 1120ms reset assertion after VCC recovery. Its internal 63kΩ MR pullup resistor enables direct connection of a momentary switch to GND without external components.

This device operates across 1.0V–5.5V supply range, draws only 3μA at 1.8V, and features negative-going VCC transient immunity up to 35µs at 100mV overdrive. Reset output remains valid during brownout conditions and asserts within 35µs of VCC falling below threshold.

Key Specifications

Pinout & Package

MAX6385XS34D4-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, suitable 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 MAX6385XS34D3-T and TPS3808G33DBVR, MAX6385XS34D4-T provides longer reset hold time for complex boot sequences and eliminates an external component via its internal MR pullup, reducing BOM cost and improving layout density in compact SC70-4 designs.

Availability

MAX6385XS34D4-T is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, automotive body control units, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6385XS34D4-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 industrial, automotive, communications, and computing markets.

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

FAQ

What is the exact reset threshold voltage of MAX6385XS34D4-T and how stable is it over temperature?

The MAX6385XS34D4-T has a factory-set nominal reset threshold of 3.40V, with guaranteed accuracy of ±2.5% over the full operating temperature range of -40°C to +125°C. This corresponds to a minimum threshold of 3.32V and maximum of 3.49V at extreme temperatures. The device achieves this stability using a precision bandgap reference and laser-trimmed resistive divider, eliminating need for external calibration. This level of tolerance ensures robust detection of 3.3V rail brownout without false triggering.

Does MAX6385XS34D4-T support manual reset functionality, and what external components are required?

Yes, MAX6385XS34D4-T includes a dedicated MR (manual reset) input on Pin 3 with an internal 63kΩ pullup resistor to VCC. No external components are required - simply connect a normally open momentary switch between MR and GND to implement field-service reset. The device guarantees MR recognition with pulse widths as short as 1µs and rejects noise spikes <100ns. This integrated feature reduces BOM count and improves reliability compared to solutions requiring discrete pullup resistors.

What is the reset output configuration of MAX6385XS34D4-T and how does it interface with common microcontrollers?

MAX6385XS34D4-T features an active-high push-pull reset output on Pin 2. When asserted, it drives the RESET line high (VOH ≥ 0.8×VCC at 150µA source); when deasserted, it pulls low (VOL ≤ 0.3V at 80µA sink). This eliminates need for external pullup resistors and provides direct compatibility with standard μP RESET inputs that expect active-high signaling, including many ARM Cortex-M, Renesas RX, and Microchip PIC32 devices. The output remains valid down to VCC = 1.0V.

How does the 1120ms reset timeout of MAX6385XS34D4-T benefit system-level design?

The 1120ms minimum VCC reset timeout in MAX6385XS34D4-T ensures the microprocessor remains held in reset long enough for all power rails, clocks, and peripheral regulators to stabilize after power-up or brownout recovery. This prevents race conditions during boot sequence, avoids corrupted flash writes, and guarantees proper initialization of analog subsystems like ADCs and DACs. In contrast, shorter timeouts (e.g., 140ms) may release reset before auxiliary supplies settle, leading to unpredictable startup behavior in multi-rail systems.

Is MAX6385XS34D4-T qualified for automotive applications, and what package options are available?

MAX6385XS34D4-T is offered in a RoHS-compliant 4-pin SC70 package (outline 21-0098) but is not explicitly automotive-qualified (i.e., lacks /V suffix per ordering guide). For AEC-Q100 Grade 2 (-40°C to +105°C) or Grade 1 (-40°C to +125°C) compliance, designers should select variants with /V suffix such as MAX6385XS34D4/V+T. The base MAX6385XS34D4-T operates across -40°C to +125°C and meets industrial reliability standards, making it suitable for non-safety-critical automotive body electronics where full qualification is not mandated.