Analog Devices Inc. ADM823LYRJZ-R7

Overview

ADM823LYRJZ-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 4.63 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 for automotive-grade reliability.

For engineers reviewing the ADM823LYRJZ-R7 datasheet, ADM823LYRJZ-R7 pinout, ADM823LYRJZ-R7 application, or ADM823LYRJZ-R7 equivalent, key selection considerations include reset threshold accuracy (±0.07 V at 25°C), guaranteed reset validity down to VCC = 1 V, internal 52 kΩ MR pull-up, WDI transition detection as short as 50 ns, and SC70/SOT-23 package compatibility in automotive temperature range.

Technical Context

The ADM823LYRJZ-R7 implements a precision bandgap-based reset comparator with 40 ppm/°C temperature coefficient and 10 mV hysteresis, ensuring stable threshold behavior over −40°C to +125°C. Its watchdog timer resets on missing logic transitions at WDI-cleared by any low-to-high or high-to-low edge-and is disabled when WDI floats.

Reset assertion occurs on VCC drop below 4.63 V (min 4.50 V, max 4.75 V over temp), MR low pulse ≥1 µs, or WDI timeout ≥1.12 sec. The push-pull RESET output sinks 3.2 mA at VCC = VTH min and remains valid down to VCC = 1 V, supporting brownout recovery in safety-critical embedded systems.

Key Specifications

Pinout & Package

ADM823LYRJZ-R7 is housed in a 5-lead SOT-23 (RJ-5) package per JEDEC MO-178-AA, with 0.95 mm lead pitch and 2.90 × 1.60 mm body size. Thermal resistance θJA is 270°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT46D3+ and TPS3808G33DBVR, ADM823LYRJZ-R7 uniquely combines 4.63 V threshold, integrated watchdog timer, manual reset input, and full automotive temperature qualification in a single 5-pin SOT-23 package-making it the only option among the three that satisfies concurrent requirements for 5 V system supervision, firmware execution monitoring, and AEC-Q100-compliant deployment.

Availability

ADM823LYRJZ-R7 is available at Aetrix Electronics and suitable for engine control units, industrial PLCs, medical infusion pumps, and automotive body control modules requiring stable component supply with automotive-grade reliability and long-term lifecycle support.

Supply support for ADM823LYRJZ-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, Inc. is a global semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, industrial automation, and automotive systems.

The ADM823 family delivers automotive-qualified power supervision with integrated watchdog and manual reset-designed specifically for microprocessor-based systems demanding robust startup, brownout recovery, and runtime fault detection in harsh environments.

FAQ

What is the exact reset threshold voltage of ADM823LYRJZ-R7 and how does it vary with temperature?

The ADM823LYRJZ-R7 has a nominal reset threshold of 4.63 V at 25°C, with a guaranteed range of 4.50 V to 4.75 V across −40°C to +125°C. Its temperature coefficient is 40 ppm/°C, meaning threshold drift is limited to ±12 mV over the full automotive temperature range-ensuring consistent power-on reset behavior in extreme thermal conditions. This specification is confirmed in Table 2 of the Rev. D datasheet.

Does ADM823LYRJZ-R7 support operation down to 1 V supply voltage, and what is the RESET output behavior at that level?

Yes, ADM823LYRJZ-R7 guarantees valid RESET output down to VCC = 1 V, as specified in the "RESET Output Voltage" section of the datasheet. At VCC = 1 V and sinking 50 µA, the RESET pin remains logic-low (≤0.3 V), enabling safe microprocessor hold states during deep brownout. This capability is intrinsic to the push-pull output architecture and is validated across the full temperature range.

What is the minimum pulse width required on the MR pin to trigger a reset on ADM823LYRJZ-R7?

The ADM823LYRJZ-R7 requires a minimum MR low pulse width of 1 µs to assert reset, as stated in Table 4 and confirmed in Figure 13 of the datasheet. The internal debounce circuit rejects glitches shorter than 100 ns, ensuring noise immunity while maintaining responsiveness to intentional manual reset actions. This timing is consistent across −40°C to +125°C.

Can the watchdog timer in ADM823LYRJZ-R7 be disabled, and if so, how?

Yes, the watchdog timer in ADM823LYRJZ-R7 can be disabled by leaving the WDI pin unconnected (floating). As described in the Applications Information section, an internal window comparator disconnects the watchdog timer from the reset output circuitry when WDI is floating-preventing timeout-induced resets while retaining undervoltage and manual reset functionality.

What package type and footprint does ADM823LYRJZ-R7 use, and is it compatible with standard SOT-23 reflow profiles?

ADM823LYRJZ-R7 uses a 5-lead SOT-23 package (JEDEC MO-178-AA, package option RJ-5), with 0.95 mm lead pitch and 2.90 × 1.60 mm body dimensions. It is fully compatible with standard SnPb and lead-free reflow profiles per JEDEC J-STD-020, with maximum soldering temperature of 260°C for 10 seconds as specified in the Absolute Maximum Ratings table.