Analog Devices Inc. ADM823TYRJ-R7

Overview

ADM823TYRJ-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 3.08 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 ADM823TYRJ-R7 datasheet, ADM823TYRJ-R7 pinout, ADM823TYRJ-R7 application, or ADM823TYRJ-R7 equivalent, key selection criteria include reset threshold accuracy (±30 mV over temperature), guaranteed reset validity down to VCC = 1 V, MR input pulse width tolerance (≥1 µs), WDI transition detection (50 ns min), and SC70/SOT-23 package compatibility in low-power embedded systems.

Technical Context

The ADM823TYRJ-R7 implements a precision bandgap-based reset comparator with 40 ppm/°C temperature coefficient and 5 mV hysteresis, ensuring stable threshold behavior across automotive temperature ranges. Its watchdog timer resets on missing logic transitions at WDI - cleared by any edge (low-to-high or high-to-low) - and is disabled when WDI floats.

Reset assertion occurs on VCC drop below 3.08 V (±30 mV), MR pull-down, or WDI timeout; deassertion requires VCC rise above threshold plus 140–280 ms timeout. The internal 52 kΩ MR pull-up eliminates external components, and push-pull output drives RESET directly without external pull-ups.

Key Specifications

Pinout & Package

ADM823TYRJ-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 dimensions. Pin 1 is RESET (active-low push-pull), Pin 2 is GND, Pin 3 is MR (active-low manual reset input), Pin 4 is VCC (monitored supply), and Pin 5 is WDI (watchdog input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326TUT+T and TPS3808G30DBVR, ADM823TYRJ-R7 uniquely integrates watchdog timer, manual reset input, and push-pull output in a 5-pin SOT-23 - eliminating external components needed for MR pull-up and RESET drive while maintaining automotive temperature support and sub-µA quiescent current.

Availability

ADM823TYRJ-R7 is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLC modules, medical patient monitors, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM823TYRJ-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 semiconductor company specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control applications.

The ADM823 family delivers automotive-qualified supervisory circuits optimized for microprocessor-based systems needing simultaneous voltage monitoring, watchdog-based fault recovery, and field-serviceable manual reset - targeting harsh-environment embedded control.

FAQ

What is the exact reset threshold voltage of ADM823TYRJ-R7 and its tolerance over temperature?

The ADM823TYRJ-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 the full −40°C to +125°C operating temperature range. This 150 mV window reflects ±30 mV variation around the typical value, supported by 40 ppm/°C temperature coefficient and 5 mV hysteresis to prevent chatter near threshold.

Does ADM823TYRJ-R7 require external components for manual reset functionality?

No, ADM823TYRJ-R7 includes an internal 52 kΩ pull-up resistor on the MR pin, allowing direct connection of a push-button switch between MR and ground without external components. The device also integrates debounce circuitry and rejects MR glitches shorter than 100 ns, making it fully self-contained for manual reset implementation.

How does the watchdog timer in ADM823TYRJ-R7 respond to microcontroller GPIO toggling?

The ADM823TYRJ-R7 watchdog timer clears on any logic transition (low-to-high or high-to-low) at the WDI pin, detecting pulses as short as 50 ns. When the microcontroller toggles WDI within the 1.12–2.40 sec timeout window, the timer resets; failure to toggle results in automatic RESET assertion, restarting the microcontroller in a known state.

Can ADM823TYRJ-R7 operate reliably during deep brownout conditions?

Yes, ADM823TYRJ-R7 guarantees valid RESET output down to VCC = 1 V, and continues functional operation as low as 1.2 V over temperature. Its push-pull output maintains defined logic states even during severe supply droop, ensuring deterministic reset signaling before complete power collapse - critical for fail-safe embedded systems.

What package type and footprint does ADM823TYRJ-R7 use, and is it compatible with standard SOT-23 reflow profiles?

ADM823TYRJ-R7 uses the 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. It is compatible with standard lead-free reflow profiles, including peak temperatures up to 260°C for 10 seconds, and has θJA thermal impedance of 270°C/W - supporting high-density PCB layouts without thermal derating concerns.