Analog Devices Inc. ADM823MYKS-R7

Overview

ADM823MYKS-R7 from Analog Devices is a supervisory circuit with integrated watchdog timer and manual reset input, designed for microprocessor supply voltage monitoring and code execution integrity assurance. It features a 4.38 V reset threshold, 140 ms minimum reset timeout, 1.6 sec watchdog timeout, push-pull active-low RESET output, and operates across −40°C to +125°C in automotive systems.

For engineers reviewing the ADM823MYKS-R7 datasheet, ADM823MYKS-R7 pinout, ADM823MYKS-R7 application, or ADM823MYKS-R7 equivalent, key selection considerations include reset threshold accuracy (±0.05 V at 25°C), guaranteed reset validity down to VCC = 1 V, internal 52 kΩ MR pull-up, SC70-5 package footprint, and watchdog pulse width tolerance (50 ns min).

Technical Context

The ADM823MYKS-R7 implements a precision bandgap-based voltage reference with 40 ppm/°C temperature coefficient and 5 mV hysteresis to ensure stable reset assertion during brownout conditions. Its watchdog detector clears on any logic transition (low-to-high or high-to-low) at WDI, requiring servicing within 1.6 sec typical timeout to prevent system reset.

Reset generation combines three independent triggers: VCC falling below 4.38 V (±0.07 V over temperature), MR pin driven low for ≥1 µs, or WDI inactivity exceeding watchdog timeout. The push-pull RESET output sinks 1.2 mA at VTH min and remains valid down to VCC = 1 V, enabling reliable microprocessor initialization in low-voltage power-up sequences.

Key Specifications

Pinout & Package

ADM823MYKS-R7 is housed in a 5-lead SC70 (KS-5) package, measuring 2.00 mm × 1.25 mm × 0.90 mm with 0.65 mm lead pitch. This compact footprint supports high-density PCB layouts in space-constrained automotive and portable applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM823MYKS-R7, MAX6326UT43D3+T omits manual reset but matches watchdog and reset timing; TPS3808G33DBVR offers lower threshold and no watchdog, making it suitable only for simple supply monitoring-neither provides the full feature set of integrated watchdog, MR, and automotive-grade SC70 packaging found in ADM823MYKS-R7.

Availability

ADM823MYKS-R7 is available at Aetrix Electronics and suitable for automotive engine control, infotainment systems, industrial PLC modules, and portable medical devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM823MYKS-R7 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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The ADM823 family is part of Analog Devices' precision supervisory IC portfolio, engineered specifically for robust power supply monitoring and firmware watchdog functions in harsh automotive and industrial environments.

FAQ

What is the exact reset threshold voltage of the ADM823MYKS-R7 and how does it vary with temperature?

The ADM823MYKS-R7 has a nominal reset threshold of 4.38 V at 25°C, with a guaranteed range of 4.25 V to 4.50 V across the full −40°C to +125°C operating temperature range. Its temperature coefficient is tightly controlled at 40 ppm/°C, and it includes 5 mV of built-in hysteresis to prevent chatter near the trip point. This specification ensures consistent brownout detection in automotive power rails subject to thermal cycling.

Does the ADM823MYKS-R7 require external components to function as a complete supervisory solution?

No, the ADM823MYKS-R7 operates as a fully self-contained supervisory solution with no mandatory external components. It integrates an internal 52 kΩ pull-up resistor on the MR pin, a precision voltage reference, watchdog timing circuitry, and push-pull RESET output drivers. Only a 0.1 µF VCC bypass capacitor is recommended for optimal noise immunity-no resistors, capacitors, or additional ICs are needed for basic reset, watchdog, or manual reset functionality.

How does the watchdog timer in the ADM823MYKS-R7 respond to microprocessor failures?

The ADM823MYKS-R7 watchdog timer asserts RESET if no logic transition occurs on the WDI pin for longer than 1.6 sec (typical). It clears on every rising or falling edge, detecting pulses as short as 50 ns. When the microprocessor fails to toggle WDI-due to infinite loop, stack overflow, or halted execution-the timeout triggers a hardware reset, returning the system to a known state without software intervention. This behavior is confirmed in the functional block diagram and timing characteristics on page 1 of the datasheet.

Can the ADM823MYKS-R7 be used in systems with supply voltages below 2.0 V?

No, the ADM823MYKS-R7 is not specified to operate below VCC = 1 V, and its reset functionality is guaranteed only down to that level. While the RESET output remains valid at VCC = 1 V, the device requires VCC ≥ 1.2 V for full specification compliance across temperature (per Table 2, "VCC Operating Voltage Range"). For sub-2.0 V systems, such as 1.8 V or 1.2 V rails, the ADM823MYKS-R7 is unsuitable; alternative supervisors like the ADM823TYKSZ-R7 (3.08 V threshold) or dedicated low-voltage parts should be selected.

What package type and dimensions does the ADM823MYKS-R7 use, and is it compatible with standard reflow processes?

The ADM823MYKS-R7 uses the 5-lead SC70 package (JEDEC MO-203-AA, KS-5 variant), measuring 2.00 mm × 1.25 mm × 0.90 mm with 0.65 mm lead pitch. It is RoHS-compliant (indicated by the "Z" suffix) and qualified for standard Pb-free reflow soldering per J-STD-020, including peak temperatures up to 260°C for 10 seconds. Its small outline supports high-density placement in automotive and portable designs without thermal derating concerns.