Analog Devices Inc. ADM825TYRJ-R7

Overview

ADM825TYRJ-R7 from Analog Devices is a supervisory circuit with manual reset input and dual active-low/active-high push-pull reset outputs, designed for microprocessor supply voltage monitoring in automotive-grade systems. It features a 3.08 V reset threshold (±50 mV over temperature), 140 ms minimum reset timeout, guaranteed reset validity down to VCC = 1 V, and operates across −40°C to +125°C. Used in engine control units and industrial PLCs to prevent erratic behavior during brownout conditions.

For engineers reviewing the ADM825TYRJ-R7 datasheet, ADM825TYRJ-R7 pinout, ADM825TYRJ-R7 application, or ADM825TYRJ-R7 equivalent, key selection criteria include reset threshold accuracy, manual reset pulse width tolerance (≥1 µs), MR internal pull-up value (52 kΩ), and dual-output drive capability for legacy and modern reset logic interfaces.

Technical Context

The ADM825TYRJ-R7 implements a precision bandgap-based reset comparator with 40 ppm/°C temperature coefficient and 5 mV hysteresis, ensuring stable trip point across automotive temperature extremes. Its dual push-pull RESET/RESET outputs are independently asserted during VCC undervoltage, MR low assertion, or watchdog timeout - though unlike ADM823/ADM824, this variant excludes watchdog functionality entirely.

Reset assertion is synchronized to a fixed 140 ms minimum timeout after VCC rises above threshold or MR transitions high, with propagation delay under 500 ns (MR-to-RESET) and <40 µs (VCC-fall-to-RESET). The device draws only 5 µA typical supply current at VCC = 3.3 V and supports valid output states down to VCC = 1 V without external biasing.

Key Specifications

Pinout & Package

ADM825TYRJ-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 and 0.95 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and MAX6326UT33D3+, the ADM825TYRJ-R7 uniquely delivers dual push-pull outputs without external components while maintaining automotive temperature rating and 5 µA quiescent current - making it optimal for space-constrained, mixed-logic automotive modules where watchdog is unnecessary.

Availability

ADM825TYRJ-R7 is available at Aetrix Electronics and suitable for engine control units, industrial programmable logic controllers, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM825TYRJ-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 ADM825 is part of Analog Devices' precision supervisory circuit family, engineered specifically for robust power-on reset, brownout protection, and manual recovery in automotive and industrial microprocessor systems.

FAQ

What is the reset threshold voltage of the ADM825TYRJ-R7 and how does it vary with temperature?

The ADM825TYRJ-R7 has a nominal reset threshold of 3.08 V at 25°C, with a guaranteed range of 3.00 V to 3.15 V across −40°C to +125°C. Its temperature coefficient is 40 ppm/°C, resulting in ≤12 mV total drift over full automotive temperature range - sufficient for reliable 3.3 V rail supervision with 10% margin.

Does the ADM825TYRJ-R7 include a watchdog timer function?

No, the ADM825TYRJ-R7 does not include a watchdog timer. Per Table 1 in the datasheet, only ADM823 and ADM824 variants feature watchdog input (WDI); ADM825 is designated for manual-reset-only applications. The ADM825TYRJ-R7 retains dual RESET/RESET outputs and MR input but omits WDI pin and associated timing circuitry.

What are the electrical characteristics of the MR input on the ADM825TYRJ-R7?

The MR input on ADM825TYRJ-R7 is active-low with an internal 52 kΩ pull-up resistor, threshold defined as 0.3×VCC to 0.7×VCC, minimum pulse width of 1 µs, and 100 ns glitch rejection. It drives the reset outputs immediately upon detection and holds reset asserted for the full 140 ms timeout after MR returns high.

Can the ADM825TYRJ-R7 operate reliably at VCC = 1 V, and what happens to its outputs below that?

Yes, the ADM825TYRJ-R7 guarantees valid RESET and RESET output states down to VCC = 1 V - both outputs remain functional and meet specified VOL/VOH limits. Below 1 V, output behavior is undefined per Absolute Maximum Ratings; however, the device remains undamaged and resumes normal operation once VCC rises above 1 V.

What package type and lead finish does the ADM825TYRJ-R7 use, and is it RoHS compliant?

The ADM825TYRJ-R7 uses a 5-lead SOT-23 (RJ-5) package with matte tin lead finish, compliant with JEDEC MO-178-AA standards. It is RoHS compliant (lead-free) and halogen-free, as indicated by the "Z" suffix in alternate part numbers and confirmed in the Ordering Guide footnote.