Analog Devices Inc. ADM6321CY46ARJ-RL7

Overview

ADM6321CY46ARJ-RL7 from Analog Devices is a supervisory circuit with watchdog timer and open-drain active-low reset output, designed for microprocessor voltage monitoring and code execution integrity assurance. It features a 4.63 V reset threshold (±2.5% over −40°C to +85°C), 140 ms minimum reset timeout, 1.6 s typical watchdog timeout, and operates from 1 V to 5.5 V supply. It is used in industrial controllers requiring reliable brownout detection and autonomous recovery.

For engineers reviewing the ADM6321CY46ARJ-RL7 datasheet, ADM6321CY46ARJ-RL7 pinout, ADM6321CY46ARJ-RL7 application, or ADM6321CY46ARJ-RL7 equivalent, key selection criteria include reset threshold accuracy at temperature extremes, guaranteed reset validity down to VCC = 1 V, open-drain output compatibility with mixed-voltage systems, and watchdog timeout stability across operating conditions.

Technical Context

The ADM6321CY46ARJ-RL7 integrates a precision voltage reference, reset generator with hysteresis (3 mV), and a watchdog timer cleared by logic transitions on WDI. Its open-drain RESET output requires an external pull-up and supports rail-to-rail compatibility up to 6 V, enabling interface with 1.8 V, 3.3 V, or 5 V microcontrollers.

It features internal MR pull-up (52 kΩ), glitch rejection on MR (100 ns), and power supply transient immunity validated per Figure 14 - e.g., a 100 mV undershoot below 4.63 V threshold is tolerated for ≤8 µs without false reset. Reset assertion is guaranteed for VCC ≥ 1 V, and supply current is 5 µA typical at 3.6 V.

Key Specifications

Pinout & Package

ADM6321CY46ARJ-RL7 is housed in a 5-lead SOT-23 (RJ-5) package, JEDEC MO-178-AA compliant, with 1.90 mm × 2.90 mm footprint and 1.30 mm height. Pin 1 is RESET (open-drain active-low), Pin 2 is GND, Pin 3 is RESET (push-pull active-high), Pin 4 is WDI, and Pin 5 is VCC.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM6321CY46ARJ-RL7, ADM6320CY46ARJZ-R7 offers identical supervision parameters but omits the push-pull active-high output, reducing flexibility in dual-signaling designs; TPS3808G33DBVR lacks both watchdog capability and adjustable threshold, limiting its use to basic voltage monitoring.

Availability

ADM6321CY46ARJ-RL7 is available at Aetrix Electronics and suitable for industrial PLC controllers, smart energy meters, medical infusion pumps, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for ADM6321CY46ARJ-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with design centers worldwide and a legacy of precision power management innovation.

The ADM63xx family was engineered specifically for microprocessor-based systems needing robust power-on reset, brownout protection, and autonomous code-execution monitoring - targeting industrial, medical, and automotive applications demanding high reliability and low quiescent current.

FAQ

What is the exact reset threshold voltage of ADM6321CY46ARJ-RL7 and how does it vary with temperature?

The ADM6321CY46ARJ-RL7 has a nominal reset threshold of 4.63 V, specified as ±2.5% over the full industrial temperature range (−40°C to +85°C). At 25°C, tolerance tightens to ±1.5%. Temperature coefficient is 40 ppm/°C, meaning drift is bounded and predictable - e.g., maximum deviation from 4.63 V at +85°C is approximately 11.6 mV, well within the ±2.5% band. This ensures consistent brownout detection across operating environments.

Does ADM6321CY46ARJ-RL7 include a manual reset (MR) input?

No, ADM6321CY46ARJ-RL7 does not include a manual reset input. Per Table 1 and Pin Function Descriptions, ADM6321 is configured with watchdog input (WDI) and dual reset outputs (open-drain low and push-pull high), but no MR pin. This distinguishes it from ADM6316/ADM6317/ADM6320 variants. System-level reset initiation must occur via VCC monitoring or WDI timeout - external push-button reset requires discrete circuitry or a different part number.

What are the electrical characteristics of the open-drain RESET output on ADM6321CY46ARJ-RL7?

The open-drain RESET output on ADM6321CY46ARJ-RL7 sinks ≤0.3 V at 50 µA (VCC ≥ 1.0 V), ≤0.3 V at 100 µA (VCC ≥ 1.2 V), and ≤0.4 V at 3.2 mA (VCC ≥ 4.5 V). Leakage current is ≤1 µA. An external pull-up resistor (typically 10 kΩ) is mandatory, and the pulled-up voltage must not exceed 6 V. This configuration enables level translation and wired-OR reset buses in mixed-voltage systems.

How does the watchdog timer on ADM6321CY46ARJ-RL7 operate, and what is its timeout accuracy?

The ADM6321CY46ARJ-RL7 watchdog timer clears on any logic transition (low-to-high or high-to-low) on the WDI pin and times out after 1.6 s typical (Y-suffix), with min/max of 1.12 s / 2.24 s. Accuracy is affected by temperature (see Figure 13: ±10% normalized variation over −40°C to +85°C) and supply voltage. The timer also resets automatically during VCC-induced or WDI-triggered reset assertion, preventing spurious timeouts during recovery.

Is ADM6321CY46ARJ-RL7 RoHS compliant and what is its packaging format?

Yes, ADM6321CY46ARJ-RL7 is RoHS compliant (Z-suffix in ordering code). It is supplied in a 5-lead SOT-23 package (RJ-5, JEDEC MO-178-AA), tape-and-reel format, with 3,000 units per reel (RL7 suffix). The marking code is N02, and the device is rated for −40°C to +85°C operation. Lead finish is matte tin, and the package is halogen-free per Analog Devices' environmental policy.