Analog Devices Inc. ADM812ZART-REEL7

Overview

ADM812ZART-REEL7 from Analog Devices is a microprocessor supervisory circuit in 4-lead SOT-143 package, providing active-high reset output with 2.32 V reset threshold, 140–560 ms power-on reset timeout, 5 µA typical supply current, and operation over −40°C to +85°C for monitoring 2.5 V supply rails in embedded controllers.

For engineers reviewing the ADM812ZART-REEL7 datasheet, ADM812ZART-REEL7 pinout, ADM812ZART-REEL7 application, or ADM812ZART-REEL7 equivalent, key selection factors include reset threshold accuracy (±3% over temperature), manual reset debounce (10 µs min pulse width), glitch immunity (100 ns), low-voltage reset assertion down to 1 V_CC, and compatibility with 2.5 V logic systems requiring reliable brownout detection.

Technical Context

The ADM812ZART-REEL7 implements a precision bandgap voltage reference and comparator-based reset generator with internal timing capacitor, enabling deterministic reset assertion during power-up and brownout events. Its reset threshold is factory-trimmed to 2.32 V (2.25–2.38 V range) for 2.5 V supply monitoring, with 30 ppm/°C temperature coefficient ensuring stability across industrial temperature range.

It features a debounced manual reset input (MR) that ignores transients <100 ns and responds to pulses ≥10 µs, and guarantees valid RESET output down to V_CC = 1 V. The active-high RESET output drives high at 0.8 × V_CC (I_SOURCE = 150 µA) and pulls low to ≤0.3 V (I_SINK = 1.2 mA) when asserted.

Key Specifications

Pinout & Package

ADM812ZART-REEL7 uses a 4-lead SOT-143 (RA-4) package per JEDEC TO-253-AA, with gull-wing leads, 1.92 mm body width, and 0.90 mm height. Pin 1 is GND, Pin 2 is RESET (active-high output), Pin 3 is MR (active-low manual reset), and Pin 4 is V_CC (monitored supply).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX812ZTR and TPS3808G12DBVR, ADM812ZART-REEL7 delivers superior low-current performance (5 µA typical) and deeper brownout detection (valid reset to 1 V_CC), making it optimal for space-constrained, battery-sensitive 2.5 V systems where minimal BOM count and proven reliability are prioritized over added features.

Availability

ADM812ZART-REEL7 is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, portable medical sensors, smart energy meters, and other applications requiring stable component supply with RoHS-compliant packaging and industrial temperature qualification.

Supply support for ADM812ZART-REEL7 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, headquartered in Norwood, MA, with design centers worldwide.

The ADM811/ADM812 family was designed specifically for reliable, low-power microprocessor supervision in space- and power-constrained embedded systems, targeting industrial, automotive, and portable instrumentation markets.

FAQ

What is the exact reset threshold voltage of ADM812ZART-REEL7 and its tolerance over temperature?

The ADM812ZART-REEL7 has a nominal reset threshold of 2.32 V, with a guaranteed range of 2.25 V to 2.38 V over the full −40°C to +85°C operating temperature range. This 5.5% total window includes initial accuracy and 30 ppm/°C temperature coefficient, enabling precise 2.5 V supply monitoring without external calibration.

Does ADM812ZART-REEL7 support operation during severe supply brownout conditions?

Yes, ADM812ZART-REEL7 asserts valid reset output down to V_CC = 1 V, ensuring the connected microprocessor remains held in reset even during deep brownouts. Its active-high RESET output remains logically low (≤0.3 V) until V_CC recovers above threshold, preventing spurious execution.

What is the minimum pulse width required on the MR pin of ADM812ZART-REEL7 to trigger a manual reset?

The MR pin of ADM812ZART-REEL7 requires a minimum pulse width of 10 µs to guarantee recognition. Pulses shorter than 100 ns are rejected by internal hardware debouncing, making the ADM812ZART-REEL7 robust against switch bounce and EMI in noisy environments.

How does the power-on reset timeout of ADM812ZART-REEL7 behave across temperature and supply voltage?

The ADM812ZART-REEL7 provides a minimum 140 ms reset timeout after V_CC rises above threshold, extending up to 560 ms depending on V_CC level and temperature. This variation is intentional to ensure sufficient stabilization time for both power supply and microprocessor across all operating conditions.

Is ADM812ZART-REEL7 pin-compatible with other members of the ADM811/ADM812 family?

Yes, ADM812ZART-REEL7 shares identical 4-lead SOT-143 (RA-4) pinout and footprint with all ADM811/ADM812 variants, including ADM812LART-REEL7 and ADM812TARTZ-REEL7. Only the reset threshold and output polarity differ-no PCB changes are required when substituting within the same ADM812 series.