Analog Devices Inc./Maxim Integrated MAX6823LUK+

Overview

MAX6823LUK+ 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 +4.63V supply with ±3% threshold accuracy over –40°C to +125°C, asserts reset during power-up/brownout, and guarantees valid reset operation down to VCC = +1.0V - used in critical µP monitoring for portable and embedded controllers.

For engineers reviewing the MAX6823LUK+ datasheet, MAX6823LUK+ pinout, MAX6823LUK+ application, or MAX6823LUK+ equivalent, this page delivers verified electrical specs, exact pin functions, real-world use cases in battery-powered equipment and intelligent instruments, and two confirmed alternative parts with documented functional differences.

Technical Context

The MAX6823LUK+ integrates voltage monitoring, watchdog timer, and debounced manual reset in a single BiCMOS IC. Its reset generator triggers on VCC falling below 4.63V (L-suffix), holds RESET low for ≥140ms after VCC recovery, and clears the 1.6s watchdog timer on any WDI edge or MR assertion.

It uses internal 50kΩ MR pullup and supports CMOS- or open-drain-driven MR inputs; WDI accepts 50ns pulses and tolerates leakage ≤10µA when unconnected. RESET output drives low to 0.3V at 50µA sink and high to 0.8×VCC at 200µA source, ensuring compatibility with diverse µP reset inputs.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5 (U5-1 outline, 21-0057 land pattern), RoHS-compliant, surface-mountable with 0.95mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6821LUK+, the MAX6823LUK+ adds dedicated MR functionality and retains identical threshold and watchdog specs; versus TPS3808G33DBVR, it offers wider voltage range, guaranteed sub-1.0V reset validity, and integrated manual reset - making it superior for portable, multi-rail, and service-critical designs.

Availability

MAX6823LUK+ is available at Aetrix Electronics and suitable for critical µP monitoring, portable/battery-powered equipment, and intelligent instruments requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6823LUK+ 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 computing applications.

The MAX682x family targets low-voltage microprocessor supervision in space-constrained, reliability-critical systems - emphasizing ultra-low quiescent current, wide operating temperature, and integrated watchdog/manual reset functions.

FAQ

What is the exact reset threshold voltage of the MAX6823LUK+?

The MAX6823LUK+ has a factory-trimmed reset threshold of 4.63V with ±3% tolerance over –40°C to +125°C. This value is defined by the "L" suffix in the part number and is guaranteed in the Electrical Characteristics table under VTH for MAX682_L. The threshold exhibits 60ppm/°C temperature coefficient and includes 2×VTH hysteresis to prevent chatter near trip point. This makes MAX6823LUK+ ideal for monitoring +5V rails in set-top boxes and embedded controllers.

Does the MAX6823LUK+ require external components to operate?

No, the MAX6823LUK+ requires zero external components for basic operation. Its internal 50kΩ MR pullup resistor allows direct connection of a momentary switch between MR and GND; the watchdog timer is self-cleared when WDI is left floating; and the push-pull RESET output eliminates need for an external pullup. All timing functions - including 140ms reset timeout and 1.6s watchdog period - are fully internal. This integration reduces PCB area and improves reliability in portable/battery-powered equipment using MAX6823LUK+.

How does the MAX6823LUK+ handle VCC transients during operation?

The MAX6823LUK+ is designed to reject short negative-going VCC transients: it will not assert reset for pulses ≤20µs wide when the transient amplitude is ≤100mV below the 4.63V threshold. This immunity is verified in the Typical Operating Characteristics graph "Maximum VCC Transient Duration vs. Reset Threshold Overdrive." As a result, MAX6823LUK+ maintains stable operation in electrically noisy environments like industrial embedded controllers and intelligent instruments without spurious resets.

Can the watchdog timer in the MAX6823LUK+ be disabled?

Yes, the watchdog timer in the MAX6823LUK+ is disabled by leaving the WDI pin unconnected or driving it with a three-stated buffer. When floating, the internal watchdog driver generates a low-high-low pulse every ~1.4s - well within the 1.6s timeout - effectively resetting the timer continuously. No configuration register or external signal is needed. This behavior is explicitly documented in the Applications Information section and makes MAX6823LUK+ adaptable to systems where watchdog functionality is optional or handled externally.

What is the minimum VCC voltage at which the MAX6823LUK+ guarantees correct RESET output state?

The MAX6823LUK+ guarantees correct RESET output logic state down to VCC = +1.0V, as stated in the General Description and confirmed in Absolute Maximum Ratings. At VCC ≥ +1.0V, RESET remains valid - sinking 50µA to 0.3V when asserted and sourcing 200µA at 0.8×VCC when deasserted. This specification enables reliable operation during deep brownout conditions in portable/battery-powered equipment, ensuring the MAX6823LUK+ continues to protect the host µP even as battery voltage collapses.