Analog Devices Inc./Maxim Integrated MAX6730UTWD3+

Overview

MAX6730UTWD3+ from Maxim Integrated is a single-voltage microprocessor supervisor IC with active-low open-drain reset output, manual reset input, and independent watchdog timer featuring 54s startup delay and 1.68s normal timeout. It monitors VCC1 at factory-set +4.625V threshold (suffix 'WT'), provides 210ms reset timeout (suffix 'D3'), and operates over -40°C to +85°C for embedded power sequencing in telecom and industrial control systems.

For engineers reviewing the MAX6730UTWD3+ datasheet, MAX6730UTWD3+ pinout, MAX6730UTWD3+ application, or MAX6730UTWD3+ equivalent, this page delivers verified electrical specs, SOT23-6 package details, watchdog timing behavior, reset threshold hysteresis, and real-world multivoltage system integration guidance - all confirmed against Maxim's official Rev 9 datasheet.

Technical Context

The MAX6730UTWD3+ implements a dual-mode watchdog architecture: a 35s–72s initial startup period enables full system initialization after power-up or brownout, followed by a 1.12s–2.24s normal timeout for rapid fault detection during runtime. Its reset logic asserts RST low when VCC1 drops below +4.625V (±125mV), with 0.5% hysteresis and guaranteed validity down to VCC1 = +0.8V.

VCC1 monitoring is complemented by a manual reset input (MR) with 50kΩ internal pullup, 1µs minimum pulse width, and 100ns glitch rejection. The open-drain RST output requires an external pullup and supports push-pull μP interfaces via a 10kΩ series resistor to prevent contention.

Key Specifications

Pinout & Package

SOT23-6 package (6-pin, 1.6mm × 2.9mm footprint), lead(Pb)-free, RoHS-compliant, thermal resistance θJA = 230°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6730UTWD3+, MAX6326UR29D3+ omits watchdog and MR functions entirely, while TPS3808G33DBVR trades MR for push-pull RST and uses a different watchdog architecture - making MAX6730UTWD3+ uniquely suited for applications needing both manual reset and independent watchdog signaling in a single SOT23-6 package.

Availability

MAX6730UTWD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and medical electronics requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for MAX6730UTWD3+ 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, automotive, and communications applications.

The MAX6730–MAX6735 family targets microprocessor-based systems requiring multivoltage monitoring, deterministic reset timing, and robust watchdog supervision - optimized for space-constrained, high-reliability embedded platforms.

FAQ

What is the exact VCC1 reset threshold voltage for MAX6730UTWD3+?

The MAX6730UTWD3+ has a factory-set VCC1 reset threshold of +4.625V (WT suffix), with ±125mV tolerance over temperature. This value is guaranteed across the full -40°C to +85°C operating range and includes 0.5% hysteresis to prevent oscillation near the trip point. The threshold is internally trimmed and does not require external components.

Does MAX6730UTWD3+ include a manual reset input?

Yes, MAX6730UTWD3+ includes an active-low manual reset input (MR) with 50kΩ internal pullup to VCC1. It accepts standard CMOS/TTL logic levels (VIH ≥ 0.7×VCC1, VIL ≤ 0.3×VCC1), requires a minimum 1µs pulse width, and rejects glitches shorter than 100ns. MR forces RST low immediately and holds it for the full 210ms reset timeout after release.

What are the watchdog timeout periods supported by MAX6730UTWD3+?

MAX6730UTWD3+ features a dual-mode watchdog: a 35s to 72s initial startup period (typ. 54s) after any reset event, followed by a 1.12s to 2.24s normal timeout (typ. 1.68s) after the first valid WDI transition. The watchdog remains active even if WDI is left unconnected, and its output (WDO) is open-drain with external pullup required.

Is MAX6730UTWD3+ compatible with bidirectional microprocessor reset pins?

Yes, MAX6730UTWD3+ is compatible with bidirectional μP reset pins due to its open-drain RST output. To prevent logic contention, connect a 10kΩ resistor between RST and the μP's reset I/O port. This configuration ensures safe voltage translation and avoids bus conflicts during reset assertion or release.

What package type and footprint does MAX6730UTWD3+ use?

MAX6730UTWD3+ uses a 6-pin SOT23-6 package (outline 21-0058) with 1.6mm × 2.9mm body size and 0.95mm pitch. It is lead(Pb)-free and RoHS-compliant (+T suffix), with thermal resistance θJA = 230°C/W. The pinout matches standard SOT23-6 layouts: Pin 1 = RST, Pin 2 = GND, Pin 3 = WDO, Pin 4 = VCC1, Pin 5 = WDI, Pin 6 = MR.