Analog Devices Inc./Maxim Integrated MAX6301CUA+

Overview

MAX6301CUA+ from Maxim Integrated is an adjustable low-power microprocessor supervisory circuit in 8-pin µMAX® package, featuring active-low open-drain reset output, 4µA supply current, 1.22V internal reference, and user-configurable reset/watchdog timeout via external capacitors. It monitors VCC or external supply rails in battery-powered embedded controllers requiring reliable brownout detection and watchdog supervision.

For engineers reviewing the MAX6301CUA+ datasheet, MAX6301CUA+ pinout, MAX6301CUA+ application, or MAX6301CUA+ equivalent, this page delivers verified electrical parameters, exact pin functions, real-world timing behavior (including 500× watchdog extension), thermal stability data, and validated alternative options for industrial and medical power-monitoring designs.

Technical Context

The MAX6301CUA+ implements a precision bandgap-based voltage comparator with 20mV hysteresis to detect falling VCC or external VIN below a resistor-adjustable threshold (≥1.22V). Its reset assertion is guaranteed down to VCC = 1V, and reset deassertion includes a programmable timeout (2.8–5.2ms typical with 1500pF) after threshold crossing.

Its watchdog timer uses a 500nA precision current source at SWT to generate timeout periods scalable from milliseconds (normal mode, WDS = GND) to seconds (extended mode, WDS = VCC × 500). The WDI input accepts ≥30ns pulses and clears the timer on any edge; WDS toggling resets the counter and selects mode without requiring external logic.

Key Specifications

Pinout & Package

Package: 8-pin µMAX® (U8-1), 3mm × 3mm, 0.5mm pitch, RoHS-compliant lead-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6303CUA+, the MAX6301CUA+ offers open-drain flexibility for bidirectional reset interfaces but requires a pullup; compared with TPS3808G01DBVR, it provides full configurability (threshold, reset timeout, watchdog with 500× extension) at higher design complexity and cost - essential for safety-critical or ultra-low-power systems.

Availability

MAX6301CUA+ is available at Aetrix Electronics and suitable for medical equipment, portable diagnostic devices, industrial PLC modules, and set-top box power sequencing requiring stable component supply across extended product lifecycles.

Supply support for MAX6301CUA+ 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, medical, and communications applications.

The MAX6301–MAX6304 family was engineered specifically for ultra-low-power microprocessor supervision in battery-operated and noise-prone environments, emphasizing adjustability, transient immunity, and flexible reset/watchdog architecture.

FAQ

What is the minimum VCC required for MAX6301CUA+ to assert RESET?

The MAX6301CUA+ guarantees RESET assertion at or above VCC = 1V. Below 1V, reset functionality degrades due to reduced output drive strength. This specification ensures reliable brownout detection even during deep discharge of lithium batteries - a key requirement for MAX6301CUA+ in portable medical devices where safe shutdown must occur before critical voltage collapse.

How does the 500× watchdog timeout multiplier work in MAX6301CUA+?

In MAX6301CUA+, connecting WDS to VCC activates extended watchdog mode, multiplying the base timeout (set by CSWT) by exactly 500×. For example, a 1500pF capacitor yields 4ms in normal mode and 2.0s in extended mode. This feature enables MAX6301CUA+ to serve dual roles: real-time hang detection and ultra-low-power wake-up timer - without changing hardware or firmware.

Can MAX6301CUA+ monitor voltages other than VCC?

Yes. MAX6301CUA+ monitors any voltage applied to the RESET IN pin via an external resistor divider. The device compares that voltage to its internal 1.22V reference, so VRST = 1.22 × (R1 + R2)/R2. This allows MAX6301CUA+ to supervise 1.8V, 2.5V, or 3.3V rails independently of VCC - commonly used in multi-rail embedded systems where each domain requires individual brownout protection.

What capacitor type is recommended for SRT and SWT on MAX6301CUA+?

Ceramic capacitors with leakage <10nA are recommended for both SRT and SWT on MAX6301CUA+. The internal 500nA timing current is highly sensitive to leakage; X7R or C0G dielectrics meet this requirement. Avoid electrolytic or high-leakage tantalum types, as they cause significant timeout drift. For 4ms reset timeout, use 1500pF ±10% C0G ceramic placed close to the MAX6301CUA+ pins.

Is MAX6301CUA+ compatible with bidirectional µP reset pins like the 68HC11?

Yes. MAX6301CUA+ features an open-drain active-low RESET output, enabling direct interface with bidirectional reset pins. A single external pullup resistor allows either the µP or MAX6301CUA+ to assert reset - essential for systems where the processor may also initiate reset (e.g., software watchdog or error recovery). This capability is intrinsic to MAX6301CUA+'s output structure and requires no additional components.