Analog Devices Inc. ADM825LYRJZ-R7

Overview

ADM825LYRJZ-R7 from Analog Devices is a supervisory circuit with manual reset input and dual push-pull reset outputs, designed to monitor 4.63 V supply rails in microprocessor systems. It features a 140 ms minimum reset timeout, guaranteed reset validity down to VCC = 1 V, and operates across −40°C to +125°C for automotive-grade reliability.

For engineers reviewing the ADM825LYRJZ-R7 datasheet, ADM825LYRJZ-R7 pinout, ADM825LYRJZ-R7 application, or ADM825LYRJZ-R7 equivalent, key selection criteria include reset threshold accuracy (±2.5% over temperature), MR pulse width tolerance (≥1 µs), glitch immunity against <100 ns transients, and compatibility with low-power portable or engine-control unit designs requiring robust brownout detection.

Technical Context

The ADM825LYRJZ-R7 implements a precision voltage comparator with 4.63 V nominal reset threshold (2.5% tolerance over −40°C to +125°C) and 10 mV hysteresis, ensuring stable reset assertion/deassertion during supply recovery. Its dual push-pull RESET/RESET outputs drive both active-low and active-high logic levels simultaneously without external pull resistors.

It integrates a manual reset input (MR) with internal 52 kΩ pull-up, 1 µs minimum pulse width requirement, and on-chip debounce-enabling direct connection to push-button switches. Unlike ADM823/ADM824, it omits watchdog functionality, simplifying firmware integration where code execution monitoring is handled externally.

Key Specifications

Pinout & Package

ADM825LYRJZ-R7 is housed in a 5-lead SOT-23 (RJ-5) package, 2.90 mm × 1.60 mm × 1.15 mm body size, JEDEC MO-178-AA compliant, with gull-wing leads for surface-mount assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM825LYRJZ-R7, ADM825LYRJ-R7 offers identical supervision functionality with no design impact, while TPS3808G33DBVR requires schematic and layout modifications due to single open-drain output and mismatched threshold-making it a system-level alternative rather than a direct substitute.

Availability

ADM825LYRJZ-R7 is available at Aetrix Electronics and suitable for automotive engine control units, industrial programmable logic controllers, medical infusion pumps, and ADAS camera modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM825LYRJZ-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 leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The ADM825 belongs to Analog Devices' supervisory circuits product line, engineered specifically for robust power monitoring in automotive, industrial, and medical systems where deterministic reset behavior under voltage stress is mission-critical.

FAQ

What is the exact reset threshold voltage of ADM825LYRJZ-R7 and how does it vary with temperature?

The ADM825LYRJZ-R7 has a nominal reset threshold of 4.63 V, specified from 4.50 V to 4.75 V over the full −40°C to +125°C operating range. Its temperature coefficient is 40 ppm/°C, resulting in ≤±12 mV drift across the temperature span-ensuring consistent brownout detection in automotive under-hood environments where ambient temperature swings exceed 160°C.

Does ADM825LYRJZ-R7 include a watchdog timer function?

No, ADM825LYRJZ-R7 does not include a watchdog timer. Per Table 1 in the datasheet, the ADM825 variant is defined by manual reset (MR) support and dual push-pull RESET/RESET outputs-but explicitly excludes watchdog input (WDI). For watchdog capability, select ADM823LYRJZ-R7 or ADM824LYRJZ-R7 instead.

Can ADM825LYRJZ-R7 operate reliably when VCC drops below 2 V?

Yes, ADM825LYRJZ-R7 guarantees valid RESET and RESET output states down to VCC = 1 V, as confirmed in the "RESET Output Voltage" specification table. This allows safe, predictable reset assertion during severe brownout events common in automotive cold-crank scenarios where battery voltage may fall to 1.2 V before recovery.

What is the minimum pulse width required on the MR pin to trigger a reset on ADM825LYRJZ-R7?

The MR input of ADM825LYRJZ-R7 requires a minimum low pulse width of 1 µs to assert reset, as stated in the "Manual Reset Input" section and verified in Figure 13 (MR Minimum Pulse Width vs. Temperature). The internal debounce circuit ensures reliable triggering even with mechanical switch bounce, eliminating need for external filtering.

Is ADM825LYRJZ-R7 RoHS compliant and what does the 'Z' suffix indicate?

Yes, ADM825LYRJZ-R7 is RoHS compliant-the 'Z' in the part number explicitly denotes RoHS-compliant packaging per the Ordering Guide on page 11 of the datasheet. This includes lead-free terminations and halogen-free molding compound, meeting EU Directive 2011/65/EU and IPC-1752A material declaration requirements.