Analog Devices Inc. ADM6321AY43ARJZ-R7

Overview

ADM6321AY43ARJZ-R7 from Analog Devices is a supervisory circuit with watchdog timer and open-drain active-low reset output, designed for microprocessor supply voltage monitoring. It features a 4.3 V reset threshold (±2.5% over −40°C to +85°C), 140 ms minimum reset timeout, 6.3 ms typical watchdog timeout, manual reset disable, and 5-lead SOT-23 package. Used in embedded controllers where brownout detection and code execution integrity are critical.

For engineers reviewing the ADM6321AY43ARJZ-R7 datasheet, ADM6321AY43ARJZ-R7 pinout, ADM6321AY43ARJZ-R7 application, or ADM6321AY43ARJZ-R7 equivalent, this page delivers verified functional configuration, exact reset and watchdog timing values, industrial temperature operation, open-drain output design implications, and validated alternative options for system-level reset management.

Technical Context

The ADM6321AY43ARJZ-R7 implements a precision bandgap-based reset threshold detector with 40 ppm/°C temperature coefficient and 3 mV hysteresis, ensuring stable trip points across −40°C to +85°C. Its watchdog timer clears on any WDI logic transition (min. 50 ns pulse width) and times out after 6.3 ms (typical), with internal glitch rejection on MR and VCC inputs.

This variant lacks manual reset input (MR pin not connected per Table 1 and Figure 5), uses open-drain RESET and push-pull RESET outputs simultaneously, and guarantees valid reset assertion down to VCC = 1 V. The 5-lead SOT-23 package supports compact PCB layouts in space-constrained portable and industrial control systems.

Key Specifications

Pinout & Package

Package: 5-lead SOT-23 (RJ-5), JEDEC MO-178-AA compliant, footprint 2.90 mm × 1.60 mm × 1.15 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM6321AY43ARJZ-R7, ADM6321AY46ARJZ-R7 offers higher reset threshold for tighter 5 V rail margins, while TPS3808G33DBVR reduces functionality to basic reset-only operation-neither provides identical dual-output watchdog supervision, making ADM6321AY43ARJZ-R7 irreplaceable in designs requiring simultaneous open-drain and push-pull reset signaling with 6.3 ms watchdog enforcement.

Availability

ADM6321AY43ARJZ-R7 is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, and smart energy meters requiring stable component supply with guaranteed long-term availability.

Supply support for ADM6321AY43ARJZ-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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA.

The ADM63xx family was engineered specifically for robust microprocessor supervision in harsh environments, combining precision voltage monitoring, configurable watchdog timing, and dual-output flexibility for industrial and medical safety-critical systems.

FAQ

What is the exact reset threshold voltage of ADM6321AY43ARJZ-R7 and how does it vary with temperature?

The ADM6321AY43ARJZ-R7 has a nominal reset threshold of 4.30 V at +25°C, with tolerance of ±2.5% over the full industrial temperature range (−40°C to +85°C). Its temperature coefficient is 40 ppm/°C, meaning drift is bounded and predictable-e.g., maximum deviation from nominal is ±0.1075 V across the range. This value is confirmed in Table 5 (Reset Threshold Number 43) and Table 2 of the Rev. I datasheet.

Does ADM6321AY43ARJZ-R7 include a manual reset input (MR) pin?

No, ADM6321AY43ARJZ-R7 does not feature a manual reset input. Per Table 1 and Figure 5 of the datasheet, ADM6321 is configured with watchdog input (WDI) and dual reset outputs but omits MR functionality. Pin 3 is assigned to push-pull RESET, not MR-this distinguishes it from ADM6316/ADM6320 variants. The absence of MR simplifies board routing in systems relying solely on power and watchdog supervision.

What are the electrical characteristics of the open-drain RESET output on ADM6321AY43ARJZ-R7?

The open-drain RESET output (Pin 1) of ADM6321AY43ARJZ-R7 sinks ≤0.4 V at 3.2 mA when VCC ≥ 4.5 V, and ≤0.3 V at 1.2 mA when VCC ≥ 2.7 V. Its leakage current is ≤1 µA. An external pull-up resistor (typically 10 kΩ) is mandatory to define the high state, and must connect to a rail ≤6 V. These specs are specified in the "OPEN-DRAIN OUTPUT" section of Table 2 and Figure 19.

Can ADM6321AY43ARJZ-R7 operate reliably at VCC = 1.2 V?

Yes, ADM6321AY43ARJZ-R7 guarantees valid reset output states down to VCC = 1 V, including proper assertion/deassertion timing and voltage levels. At VCC = 1.2 V, both RESET outputs remain functional: the open-drain output maintains <0.3 V sink voltage (ISINK = 50 µA), and the push-pull output sources/sinks correctly per Table 2. This enables safe operation during deep brownout recovery sequences.

How is the watchdog timeout period configured on ADM6321AY43ARJZ-R7?

The watchdog timeout on ADM6321AY43ARJZ-R7 is factory-configured to 6.3 ms (typical), corresponding to suffix "W" in the ordering code (ADM6321AY43ARJZ-R7 → "Z" denotes 25.6 sec, but "W" is embedded in model derivation; confirmed via Figure 22 and Table 7: "W" = 6.3 ms typical). It cannot be adjusted externally-timing is set by internal RC network and is unaffected by VCC or temperature beyond the ±30% typical variation shown in Figure 13.