Analog Devices Inc./Maxim Integrated MAX6302CUA+

Overview

MAX6302CUA+ from Maxim Integrated is an active-high, open-drain microprocessor supervisory circuit with adjustable reset threshold (≥1.22V), adjustable reset timeout (2.8–5.2 ms typical with 1500pF), and dual-mode watchdog timer (normal mode: 2.8–5.2 ms; extended mode: up to 2.6 s). It operates from 1.31V to 5.5V and draws only 4 µA supply current, making it suitable for battery-powered medical monitors and portable embedded controllers requiring reliable brownout detection and software hang protection.

For engineers reviewing the MAX6302CUA+ datasheet, MAX6302CUA+ pinout, MAX6302CUA+ application, or MAX6302CUA+ equivalent, this page delivers verified functional identity, confirmed 8-pin µMAX® package mapping, validated pin roles (including WDS-controlled 500× watchdog extension), real-world timing behavior under VCC transients, and two rigorously cross-checked alternative parts with documented functional and output-logic differences.

Technical Context

The MAX6302CUA+ implements a precision 1.22V internal reference driving a high-impedance reset comparator whose threshold is scaled externally via resistor divider on RESET IN. Its reset assertion is guaranteed valid down to VCC = 1.31V, and its open-drain active-high RESET output supports bidirectional µP reset I/O with external pull-up.

Watchdog operation uses two independent precision current sources (500nA) at SRT and SWT pins to charge external capacitors-enabling user-defined reset timeout (tRP) and basic watchdog timeout (tWD)-while WDS selects between normal (tWD) and extended (500×tWD) modes, with automatic timer reset on WDI or WDS transitions.

Key Specifications

Pinout & Package

MAX6302CUA+ is housed in an 8-pin µMAX® package (U8-1 outline, 3mm × 3mm, 0.5mm pitch), RoHS-compliant and lead-free, with exposed pad for thermal enhancement and mechanical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6302CUA+, MAX6304CUA+ eliminates external pull-up dependency but sacrifices bus-sharing flexibility, while TPS3808G12DBVR reduces BOM count and cost at the expense of design adaptability and watchdog capability-making MAX6302CUA+ optimal for systems needing field-programmable supervision with minimal quiescent power.

Availability

MAX6302CUA+ is available at Aetrix Electronics and suitable for medical equipment, portable instrumentation, and industrial embedded controllers requiring stable component supply across long product lifecycles and varying environmental conditions.

Supply support for MAX6302CUA+ 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, medical, and communications applications.

The MAX6301–MAX6304 family was engineered specifically for low-power, field-adjustable microprocessor supervision in space-constrained, battery-operated, and safety-critical systems where voltage margin, timing flexibility, and transient robustness are non-negotiable.

FAQ

What is the minimum VCC required for MAX6302CUA+ to assert RESET reliably?

The MAX6302CUA+ guarantees RESET assertion down to VCC = 1.31V. Below this voltage, the internal reference and comparator may not function correctly, and RESET behavior is undefined. This specification ensures reliable brownout detection even in deeply undervolted conditions common in battery-depleted portable systems. Always verify actual reset threshold voltage (VRST) using the external resistor divider formula VRST = 1.22 × (R1 + R2)/R2 when designing for marginal supply rails.

Can MAX6302CUA+ be used to monitor a 1.8V supply rail?

Yes, MAX6302CUA+ can monitor a 1.8V rail by configuring the external resistor divider on RESET IN to set VRST = 1.8V. Using R2 = 1 MΩ, R1 calculates to approximately 465 kΩ. The device's 1.31V to 5.5V operating range and ±25 mV reference accuracy ensure stable operation across temperature and process variation. Confirm timing capacitor leakage (<10 nA) and minimize PCB contamination near SRT/SWT to preserve reset timeout fidelity.

How does the WDS pin affect watchdog behavior in MAX6302CUA+?

In MAX6302CUA+, the WDS pin selects watchdog mode: grounded = normal mode (tWD), tied to VCC = extended mode (500×tWD). A state change on WDS resets the watchdog timer to zero. In extended mode, WDI can be left unconnected-the internal driver automatically pulses it near timeout to prevent reset-whereas in normal mode, WDI must be actively toggled. This dual-mode architecture enables both fast hang detection and ultra-low-power wake-up timing within one IC.

Is MAX6302CUA+ pin-compatible with MAX6301CUA+?

No, MAX6302CUA+ is not pin-compatible with MAX6301CUA+. Although both share the same 8-pin µMAX® footprint and pin numbering, their RESET output logic differs: MAX6302CUA+ provides active-high open-drain RESET (pin 7), while MAX6301CUA+ provides active-low open-drain RESET (pin 7). Swapping them without modifying the external pull-up/pull-down network will invert reset signaling and cause system malfunction. Always validate reset polarity in schematic and firmware.

What capacitor type is recommended for SRT and SWT connections on MAX6302CUA+?

Ceramic capacitors with X7R or C0G dielectric are recommended for SRT and SWT connections on MAX6302CUA+, due to their low leakage (<10 nA), stable capacitance over voltage/temperature, and minimal parasitic effects. Avoid electrolytic or high-leakage film types, as >10 nA leakage introduces significant timing error in the 500 nA current-source-based timeout circuits. Place capacitors close to the pins and route traces short and isolated from noisy signals to maintain accuracy.