Analog Devices Inc./Maxim Integrated MAX823YEXK-T

Overview

MAX823YEXK-T from Maxim Integrated is a 5-pin SC70-packaged microprocessor supervisory circuit with active-low reset, watchdog timer, and manual reset input. It monitors +2.19V power supplies with ±1.5% threshold accuracy, guarantees RESET validity down to VCC = 1V, delivers 140ms min power-on reset timeout, and provides 1.6s watchdog timeout-used in battery-powered embedded controllers for reliable brownout and software-fault recovery.

For engineers reviewing the MAX823YEXK-T datasheet, MAX823YEXK-T pinout, MAX823YEXK-T application, or MAX823YEXK-T equivalent, key selection criteria include reset threshold (2.19V), SC70-5 package compatibility, -40°C to +85°C operating range, 2µA supply current, and integrated watchdog/manual reset functionality without external components.

Technical Context

The MAX823YEXK-T implements a precision bandgap-based reset comparator with 5mV hysteresis and 40ppm/°C temperature coefficient, ensuring stable threshold behavior across its full -40°C to +85°C range. Its internal watchdog timer clears on any WDI edge (≥50ns pulse width) and triggers reset if WDI remains static >1.6s.

Reset assertion occurs when VCC falls below 2.19V (±1.5%), during MR low assertion, or upon watchdog timeout; RESET remains low for ≥140ms after VCC recovery or MR release. The device drives RESET with 1.2mA sink capability at VCC = VRST min and supports bidirectional µP reset pins via controlled pullup current (400µA max).

Key Specifications

Pinout & Package

MAX823YEXK-T uses the 5-pin SC70-5 package (2.0mm × 1.25mm × 0.9mm), optimized for space-constrained portable designs. Pin 1 is RESET (active-low open-drain), Pin 2 is GND, Pin 3 is WDI, Pin 4 is MR, and Pin 5 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX823TEXK-T, MAX823YEXK-T enables precise +2.2V rail supervision without design change, while TPS3808G12DBVR omits critical watchdog/MR functionality and cannot substitute without circuit revision and layout modification.

Availability

MAX823YEXK-T is available at Aetrix Electronics and suitable for battery-powered IoT sensor nodes, industrial PLC I/O modules, and automotive body control modules requiring stable component supply, long-lifecycle support, and lead-free compliance.

Supply support for MAX823YEXK-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 (now part of Analog Devices) designs precision analog, mixed-signal, and power-management ICs for industrial, automotive, and computing applications.

The MAX823 family targets space- and power-constrained embedded systems needing reliable power-on reset, brownout protection, and software-fault recovery via integrated watchdog and manual reset-optimized for SC70/SOT23 footprints.

FAQ

What is the exact reset threshold voltage of MAX823YEXK-T and how tightly is it specified?

The MAX823YEXK-T has a factory-trimmed reset threshold of 2.19V with ±1.5% initial accuracy over temperature (–40°C to +85°C) and 40ppm/°C temperature coefficient. This value is confirmed in the Reset Threshold Table and Electrical Characteristics section of the official datasheet, where VRST = 2.16V (min), 2.19V (typ), and 2.22V (max) at TA = TMIN to TMAX. The 2.19V threshold specifically targets +2.2V power rails in low-voltage portable systems.

Does MAX823YEXK-T support manual reset and watchdog functions simultaneously?

Yes, MAX823YEXK-T fully supports both manual reset and watchdog functions concurrently. Pin 4 (MR) provides active-low manual reset with internal 52kΩ pullup, and Pin 3 (WDI) accepts edge-triggered watchdog pulses with 1.6s timeout. The functional diagram and Pin Description confirm coexistence: MR assertion forces RESET low immediately, while WDI inactivity >1.6s also triggers RESET-both paths feed the same reset generator block.

What package type and footprint does MAX823YEXK-T use, and is it RoHS-compliant?

MAX823YEXK-T uses the SC70-5 package (2.0mm × 1.25mm × 0.9mm), as stated in the Ordering Information table. The "-T" suffix denotes tape-and-reel packaging with lead-free finish; per the datasheet note, lead-free versions are ordered by replacing "-T" with "+T", confirming RoHS compliance for standard -T parts through Maxim's lead-free qualification process.

How does MAX823YEXK-T behave when VCC drops below 1V, and what is its minimum functional supply voltage?

MAX823YEXK-T guarantees correct RESET output state (logic low) for VCC down to 1V, as explicitly stated in the General Description and Electrical Characteristics tables. Below 1V, the device ceases to function predictably-no timing or logic guarantees apply. This 1V lower limit enables robust brownout detection in systems where VCC may sag deeply before complete collapse, unlike many supervisors that lose reset integrity below 1.5V.

Can MAX823YEXK-T drive a microcontroller's bidirectional reset pin directly, and what is its sink/source capability?

Yes, MAX823YEXK-T can interface directly with bidirectional µP reset pins such as those on the 68HC11. Its RESET pin is open-drain and sinks up to 1.2mA at VCC = VRST min (2.25V), while its maximum pullup current is 400µA-low enough to allow the µP to override RESET high when needed. Figure 4 in the datasheet confirms this interoperability, specifying ISINK = 1.2mA and ISOURCE = 400µA for T/S/R/Z/Y variants like MAX823YEXK-T.