Analog Devices Inc./Maxim Integrated MAX6823VUK+T

Overview

MAX6823VUK+T from Maxim Integrated is a low-voltage microprocessor supervisory IC in 5-pin SOT23 package, featuring push-pull active-low RESET output, manual reset input (MR), and 1.6s watchdog timer. It monitors +1.58V supply with ±3% threshold accuracy over –40°C to +125°C, asserts reset during power-up/brownout, and guarantees valid reset down to VCC = +1.0V - ideal for critical µP monitoring in portable and embedded systems.

For engineers reviewing the MAX6823VUK+T datasheet, MAX6823VUK+T pinout, MAX6823VUK+T application, or MAX6823VUK+T equivalent, key selection criteria include its 1.58V reset threshold, 140ms minimum reset timeout, MR debounce capability, watchdog immunity to stuck loops, and guaranteed operation at ultra-low VCC - all verified for industrial-temperature SOT23-5 deployment.

Technical Context

The MAX6823VUK+T implements a precision bandgap-based voltage monitor with 60ppm/°C temperature coefficient and 2×VTH hysteresis, paired with a digitally timed 1.6s watchdog that clears on any WDI edge. Its MR input includes a 50kΩ internal pullup and 200ns propagation delay, enabling direct switch connection without external RC.

Reset assertion logic combines three independent triggers: VCC falling below 1.58V (±3%), MR pulled low, or WDI stall >1.6s. The push-pull active-low RESET output drives up to 3.2mA sink at VCC ≥4.25V with VOL ≤0.4V, and maintains valid state down to VCC = +1.0V - ensuring deterministic behavior during deep brownout recovery.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (U5-1 outline), footprint 91-0174, RoHS-compliant lead(Pb)-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6823VUK+T, MAX6822VUK+T offers identical monitoring and watchdog functionality but requires external pullup for RESET, while TPS3808G16DBVR removes MR and WDI entirely - making MAX6823VUK+T the only choice when both manual reset and watchdog are mandatory for system-level fault coverage.

Availability

MAX6823VUK+T is available at Aetrix Electronics and suitable for set-top boxes, embedded controllers, and portable/battery-powered equipment requiring stable component supply across industrial temperature ranges and long production lifecycles.

Supply support for MAX6823VUK+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 designs high-performance analog and mixed-signal semiconductor solutions for industrial, computing, communications, and consumer markets.

The MAX682x family delivers compact, low-power µP supervision with integrated watchdog and manual reset - engineered specifically for space-constrained, battery-sensitive, and mission-critical embedded systems.

FAQ

What is the exact reset threshold voltage of MAX6823VUK+T and how tightly is it specified?

The MAX6823VUK+T has a factory-trimmed reset threshold of 1.58V with ±3% tolerance over the full –40°C to +125°C operating range. This value is confirmed in the Threshold Suffix Guide (suffix "V") and validated in the Electrical Characteristics table under VTH for MAX682_V, where min/max limits are 1.52V and 1.62V at TA = –40°C to +125°C. The 60ppm/°C temperature coefficient ensures minimal drift across temperature.

Does MAX6823VUK+T support operation at VCC below 1.8V, and what is the lowest guaranteed functional voltage?

Yes, MAX6823VUK+T is fully specified down to VCC = +1.2V over temperature and guarantees valid reset assertion and timing down to +1.0V. The datasheet explicitly states "outputs are guaranteed to be in the correct state for VCC down to +1.0V", and electrical characteristics for ICC, VOL, VOH, and tRP are provided at VCC as low as +1.53V (for W/V versions) and +1.0V (for reset validity). This enables use in ultra-low-voltage battery systems.

How does the watchdog timer in MAX6823VUK+T respond to a stalled microcontroller, and what is its timeout accuracy?

The MAX6823VUK+T watchdog timer triggers reset if the WDI pin remains static (high or low) for longer than 1.6s nominal. Its accuracy is ±40% over –40°C to +125°C (min 0.80s, max 2.60s), per the tWD specification. Critically, it clears on *any* WDI edge - rising or falling - so software can service it by toggling WDI at different program points, not just pulsing. This prevents false clears during stuck-loop conditions.

Can the manual reset input (MR) of MAX6823VUK+T be left unconnected, and what happens if it is?

Yes, the MR input of MAX6823VUK+T can be left unconnected because it features an internal 50kΩ pullup resistor to VCC. When floating, MR remains at VIH (>0.7×VCC), disabling manual reset. No external components are needed. If driven, MR accepts CMOS logic levels and asserts reset on logic-low pulses ≥1µs wide, with 200ns propagation delay to RESET activation and built-in 100ns glitch rejection.

What package type and footprint does MAX6823VUK+T use, and is it RoHS-compliant?

MAX6823VUK+T uses the 5-pin SOT23-5 package (outline U5-1, land pattern 91-0174). The "+T" suffix explicitly denotes lead(Pb)-free, RoHS-compliant packaging per Maxim's ordering nomenclature. The device meets JEDEC standards for SOT23-5 thermal and mechanical performance, with maximum power dissipation of 571mW at TA = +70°C and derating above that temperature.