Analog Devices Inc. ADM823SYKS-R7

Overview

ADM823SYKS-R7 from Analog Devices is a precision supervisory circuit with integrated watchdog timer and manual reset input, designed for microprocessor supply voltage monitoring in automotive-grade systems. It features a 2.93 V reset threshold (±50 mV over temperature), 140 ms minimum reset timeout, 1.6 sec watchdog timeout, push-pull active-low RESET output, and operates from VCC = 2.7 V to 3.6 V with 5 µA typical supply current. It is used in engine control units to ensure deterministic restart after brownout or code lockup.

For engineers reviewing the ADM823SYKS-R7 datasheet, ADM823SYKS-R7 pinout, ADM823SYKS-R7 application, or ADM823SYKS-R7 equivalent, key selection criteria include reset threshold accuracy at automotive temperatures, guaranteed RESET validity down to VCC = 1 V, manual reset pulse width tolerance (≥1 µs), watchdog input transition sensitivity (50 ns min), and SC70-5 package compatibility with high-density PCB layouts.

Technical Context

The ADM823SYKS-R7 implements a dual-comparator architecture: one monitors VCC against a trimmed bandgap reference (2.93 V ±2.5% at 25°C, 40 ppm/°C drift) to trigger reset on undervoltage; the other detects logic transitions on WDI to clear a 1.6 sec watchdog timer. Reset assertion persists for ≥140 ms after VCC recovery, independent of MR or WDI events.

Its manual reset input (MR) includes on-chip 52 kΩ pull-up and 100 ns glitch rejection, while the push-pull RESET output guarantees logic low ≤0.3 V at 1.2 mA sink load even at VCC = 1 V - enabling reliable microcontroller reset signaling during deep brownout conditions.

Key Specifications

Pinout & Package

ADM823SYKS-R7 is housed in a 5-lead SC70 (KS-5) package, 2.0 mm × 1.25 mm × 0.9 mm, compliant with JEDEC MO-203-AA, optimized for space-constrained automotive modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT29D3+T and TPS3808G33DBVR, the ADM823SYKS-R7 uniquely combines 2.93 V precision threshold, integrated watchdog timer, manual reset input, and SC70-5 packaging - making it the sole option among the three qualified for automotive applications requiring all three functions in minimal area.

Availability

ADM823SYKS-R7 is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, and electric power steering systems requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM823SYKS-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 was developed specifically for automotive and industrial microprocessor supervision, emphasizing precision threshold stability, low-power operation, and robustness against supply transients and EMI.

FAQ

What is the exact reset threshold voltage of the ADM823SYKS-R7 and how does it vary with temperature?

The ADM823SYKS-R7 has a nominal reset threshold of 2.93 V at 25°C, with a guaranteed range of 2.85 V to 3.00 V across the full −40°C to +125°C automotive temperature range. Its temperature coefficient is 40 ppm/°C, meaning threshold drift is limited to ±11.7 mV over the entire range - critical for maintaining reliable reset behavior in under-hood environments where ambient temperature swings exceed 160°C.

Does the ADM823SYKS-R7 provide a valid reset signal when VCC drops below 1.5 V?

Yes, the ADM823SYKS-R7 guarantees RESET output validity down to VCC = 1 V. Its push-pull driver maintains logic low ≤0.3 V at 1.2 mA sink load and logic high ≥0.8×VCC even at VCC = 1 V, ensuring compatible reset signaling to modern ultra-low-voltage microcontrollers during deep brownout conditions - a key differentiator versus many competitors that cease operation below 1.8 V.

Can the watchdog timer in the ADM823SYKS-R7 be disabled, and if so, how?

Yes, the watchdog timer in the ADM823SYKS-R7 can be disabled by leaving the WDI pin unconnected (floating). The device incorporates a window comparator that disconnects the watchdog timer from the reset output circuitry when WDI is floating, preventing unintended resets. Alternatively, tri-stating the WDI driver achieves the same effect - allowing firmware flexibility to enable or disable watchdog supervision dynamically.

What is the minimum pulse width required on the MR pin to assert reset in the ADM823SYKS-R7?

The ADM823SYKS-R7 requires a minimum MR input pulse width of 1 µs to reliably assert reset. This specification is guaranteed over the full −40°C to +125°C temperature range and accounts for internal debounce circuitry. The MR pin also features 100 ns glitch rejection, ensuring noise spikes do not falsely trigger reset - essential for robust operation in electrically noisy automotive environments.

Is the ADM823SYKS-R7 RoHS compliant and what package does it use?

Yes, the ADM823SYKS-R7 is RoHS compliant (indicated by the "Z" suffix per Analog Devices ordering guide) and uses the 5-lead SC70 (KS-5) package - measuring 2.0 mm × 1.25 mm × 0.9 mm with 0.65 mm lead pitch. This JEDEC MO-203-AA compliant package supports reflow soldering and is optimized for high-density automotive PCBs where board space is constrained.