Analog Devices Inc. ADM1817-R22ART-RL7

Overview

ADM1817-R22ART-RL7 from Analog Devices is an active-high push-pull microprocessor reset circuit designed to monitor 2.5 V, 3 V, and 3.3 V power supplies. It features a precise 2.18 V (typical) reset threshold, 150 ms reset timeout, and operates across −40°C to +105°C. Used in embedded controllers and industrial microprocessor systems for safe power-up initialization.

For engineers reviewing the ADM1817-R22ART-RL7 datasheet, ADM1817-R22ART-RL7 pinout, ADM1817-R22ART-RL7 application, or ADM1817-R22ART-RL7 equivalent, key selection criteria include trip point accuracy, active-high output compatibility with MCU reset inputs, SOT-23 package footprint, and guaranteed reset timing under temperature variation.

Technical Context

The ADM1817-R22ART-RL7 integrates a precision voltage reference, comparator, and 150 ms delay timer in a single monolithic IC. Its active-high push-pull output drives directly into most microprocessor reset pins without external pull-up components.

It uses internal hysteresis and temperature-compensated threshold detection to ensure reliable reset assertion during brown-out conditions. The device asserts reset while VCC remains below 2.18 V (typ), holds reset for ≥150 ms after VCC rises above threshold, and releases reset cleanly upon stabilization.

Key Specifications

Pinout & Package

ADM1817-R22ART-RL7 is housed in a 3-lead SOT-23 (RT-3) package with gull-wing leads, JEDEC TO-236-AB compliant, 2.90 mm × 1.30 mm body size, and 0.95 mm height.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervisor applications.

Compared with ADM1817-R22ART-RL7, ADM1817-R23ART-RL7 offers earlier reset activation for margin-critical 2.5 V rails, while TPS3808G18DBVR trades push-pull convenience for open-drain configurability-both require layout review for reset signal integrity and timing alignment.

Availability

ADM1817-R22ART-RL7 is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical handheld diagnostics, and smart energy meters requiring stable component supply and guaranteed long-term availability.

Supply support for ADM1817-R22ART-RL7 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.

The ADM181x family was engineered specifically for reliable, low-cost microprocessor reset supervision in space- and power-constrained embedded systems, emphasizing precision threshold stability and guaranteed timing across wide temperature ranges.

FAQ

What is the exact reset threshold voltage of the ADM1817-R22ART-RL7?

The ADM1817-R22ART-RL7 has a typical reset threshold of 2.18 V, with a guaranteed range of 2.12 V (min) to 2.25 V (max) over −40°C to +105°C. This value is specified in Table 1 of the Rev. F datasheet and applies exclusively to the R22 variant, distinguishing it from other members of the ADM1817 series such as R23 (2.31 V) or -20 (2.55 V).

Does the ADM1817-R22ART-RL7 require an external pull-up resistor on its RST pin?

No, the ADM1817-R22ART-RL7 does not require an external pull-up resistor because it features an active-high push-pull output stage. Its RST pin drives high actively when released and low actively when asserted, enabling direct connection to microprocessor reset inputs without additional components-unlike open-drain alternatives such as ADM1816-R22ART-RL7.

What package type and dimensions does the ADM1817-R22ART-RL7 use?

The ADM1817-R22ART-RL7 uses the 3-lead SOT-23 (RT-3) package per JEDEC TO-236-AB, measuring 2.90 mm × 1.30 mm × 0.95 mm with 0.95 mm lead pitch. Pin 1 is RST, Pin 2 is VCC, and Pin 3 is GND-confirmed in Figure 2 and Table 3 of the Rev. F datasheet.

Can the ADM1817-R22ART-RL7 monitor a 3.3 V supply rail?

Yes, the ADM1817-R22ART-RL7 can monitor a 3.3 V supply rail, but it does so indirectly by supervising a derived 2.5 V domain (e.g., from a 3.3 V-to-2.5 V LDO). Its 2.18 V threshold is optimized for 2.5 V systems; for direct 3.3 V supervision, ADM1817-10ART-RL7 (2.88 V) or ADM1817-5ART-RL7 (3.06 V) are appropriate alternatives.

What is the reset timeout duration of the ADM1817-R22ART-RL7, and is it adjustable?

ADM1817-R22ART-RL7 provides a fixed reset timeout of 100 ms (min), 150 ms (typ), and 250 ms (max) from VCC rising above threshold to RST deassertion. This delay is internally generated and non-adjustable-designed to ensure power supply stabilization without external timing components.