Analog Devices Inc./Maxim Integrated MAX6823TUK

Overview

MAX6823TUK from Maxim Integrated is a low-voltage microprocessor supervisory IC in SOT23-5 package, providing active-low push-pull RESET output, manual reset input (MR), and 1.6s watchdog timer. It monitors +3.08V supply with ±1.5% threshold accuracy over -40°C to +125°C, asserts reset for ≥140ms after VCC recovery, and guarantees valid reset operation down to VCC = +1.0V. Used in embedded controllers and portable equipment for reliable power-on/power-fail sequencing.

For engineers reviewing the MAX6823TUK datasheet, MAX6823TUK pinout, MAX6823TUK application, or MAX6823TUK equivalent, this page delivers verified functional identity, exact reset threshold (3.08V), watchdog timeout (1.6s), reset timeout (140ms min), MR timing (200ns delay), and guaranteed operation at VCC = +1.0V - all critical for brownout resilience and µP startup integrity.

Technical Context

The MAX6823TUK integrates a precision voltage monitor with hysteresis (2×VTH), a monostable reset timeout generator (140ms min), and a watchdog timer with edge-triggered clearing logic. Its MR input features internal 50kΩ pullup and 100ns glitch rejection, while WDI accepts 50ns minimum pulses and clears the 1.6s timer on any rising or falling edge.

Reset assertion occurs when VCC falls below 3.08V, MR is pulled low, or WDI remains static beyond 1.6s; RESET remains active for the full timeout period regardless of VCC recovery timing. The push-pull output drives high (VOH ≥ 0.8×VCC) and low (VOL ≤ 0.4V at 3.2mA) with guaranteed state validity down to VCC = +1.0V.

Key Specifications

Pinout & Package

Package: 5-pin SOT23-5, surface-mount, 2.9mm × 1.6mm footprint, JEDEC MO-178AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6823TUK, MAX6821TUK offers identical monitoring and timing but inverted reset polarity - limiting interoperability without hardware changes - while TPS3808G30DBVR trades watchdog capability and push-pull drive for tighter threshold accuracy and broader supply range, making it suitable only for non-watchdog applications.

Availability

MAX6823TUK is available at Aetrix Electronics and suitable for embedded controllers, portable/battery-powered equipment, and automotive body control modules requiring stable component supply across extended temperature ranges (-40°C to +125°C).

Supply support for MAX6823TUK 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, automotive, and computing applications.

The MAX682x family was engineered specifically for robust microprocessor supervision in space-constrained, wide-temperature embedded systems - integrating voltage monitoring, manual reset, and watchdog functions into a 5-pin SOT23 package.

FAQ

What is the exact reset threshold voltage of the MAX6823TUK?

The MAX6823TUK has a factory-trimmed reset threshold of 3.08V, specified with ±1.5% tolerance over the full -40°C to +125°C temperature range. This value is confirmed in the Threshold Suffix Guide (suffix "T") and Electrical Characteristics table, where VTH = 3.00V to 3.15V at -40°C to +85°C and 2.97V to 3.17V at -40°C to +125°C. The MAX6823TUK is designed for reliable supervision of +3.3V rails under varying thermal and load conditions.

Does the MAX6823TUK include a watchdog timer, and what is its timeout period?

Yes, the MAX6823TUK includes a watchdog timer with a nominal timeout period of 1.6 seconds. The datasheet specifies a range of 0.80s to 2.60s over the full -40°C to +125°C operating temperature range. The timer is edge-triggered - cleared on any rising or falling transition at the WDI pin - and remains disabled if WDI is left unconnected or three-stated. This feature enables robust software execution monitoring in the MAX6823TUK without external timing components.

What type of RESET output does the MAX6823TUK provide, and how is it electrically characterized?

The MAX6823TUK provides an active-low push-pull RESET output. When asserted, RESET is driven low with VOL ≤ 0.4V at ISINK = 3.2mA (for VCC ≥ 4.25V); when deasserted, it drives high with VOH ≥ 0.8×VCC at ISOURCE = 800µA (for VCC ≥ 4.75V). Unlike open-drain variants, the MAX6823TUK requires no external pullup resistor and interfaces directly with standard active-low µP reset inputs - a key differentiator from the MAX6822TUK.

Can the MAX6823TUK operate reliably at very low supply voltages?

Yes, the MAX6823TUK guarantees correct RESET output state down to VCC = +1.0V, as explicitly stated in the General Description and Electrical Characteristics. This ensures deterministic reset behavior during severe brownout conditions where other supervisors may fail or oscillate. The internal circuitry remains functional and the reset signal remains valid even when VCC drops below the 3.08V threshold - a critical capability for fail-safe operation in the MAX6823TUK.

How does the manual reset (MR) input function in the MAX6823TUK, and what are its timing characteristics?

The MR input of the MAX6823TUK is active-low with an internal 50kΩ pullup to VCC. Pulling MR ≤ 0.3×VCC asserts reset immediately; reset remains active for the full 140ms timeout period after MR returns high. The datasheet specifies MR-to-RESET delay as 200ns and MR glitch rejection as 100ns, enabling noise-immune manual reset using a simple momentary switch to GND - no external debounce components are needed. This behavior is consistent across all MAX6823TUK units.