Analog Devices Inc. ADM6320CZ27ARJZ-R7

Overview

ADM6320CZ27ARJZ-R7 from Analog Devices is a supervisory circuit with watchdog timer and manual reset, configured for 2.7 V reset threshold, 140 ms minimum reset timeout, and 25.6 s typical watchdog timeout. It features open-drain active-low RESET output, operates from 1 V to 5.5 V supply, consumes ≤12 µA at 3.6 V, and is rated for −40°C to +85°C industrial temperature range. It is used in microprocessor-based portable equipment to ensure reliable power-on reset and code execution integrity.

For engineers reviewing the ADM6320CZ27ARJZ-R7 datasheet, ADM6320CZ27ARJZ-R7 pinout, ADM6320CZ27ARJZ-R7 application, or ADM6320CZ27ARJZ-R7 equivalent, key selection considerations include its open-drain RESET output requiring external pull-up, 25.6 s watchdog timeout for long-cycle monitoring, 2.7 V threshold compatibility with 3.3 V systems, and SOT-23-5 package constraints for space-constrained embedded designs.

Technical Context

The ADM6320CZ27ARJZ-R7 integrates a precision voltage monitor, a programmable watchdog timer cleared by WDI transitions, and a debounced manual reset input with internal 52 kΩ pull-up. Its reset generator asserts active-low output when VCC falls below 2.7 V ±2.5% over temperature, remains asserted for ≥140 ms after VCC recovery, and guarantees valid output down to VCC = 1 V.

Watchdog functionality relies on detecting logic transitions on WDI (min. 50 ns pulse width); failure to toggle within 25.6 s (typ.) triggers reset. The open-drain RESET output requires an external pull-up resistor (e.g., 10 kΩ) to a rail ≤6 V, enabling level-shifting and wired-OR configurations not possible with push-pull variants.

Key Specifications

Pinout & Package

ADM6320CZ27ARJZ-R7 is housed in a 5-lead SOT-23 (RJ-5) package per JEDEC MO-178-AA, with 0.95 mm pitch, 2.9 mm × 1.6 mm footprint, and 1.3 mm height - suitable for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6326UT27D3+T and TPS3808G33DBVR, ADM6320CZ27ARJZ-R7 uniquely combines 2.7 V threshold, 140 ms timeout, open-drain RESET, manual reset input, and 25.6 s watchdog - making it the sole option for space-constrained, battery-operated systems requiring full supervision with user intervention capability.

Availability

ADM6320CZ27ARJZ-R7 is available at Aetrix Electronics and suitable for portable medical sensors, industrial PLC I/O modules, smart energy meters, and wireless sensor nodes requiring stable component supply across extended production lifecycles.

Supply support for ADM6320CZ27ARJZ-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 semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision instrumentation, industrial automation, and communications.

The ADM63xx family was designed specifically for microprocessor-based systems needing guaranteed power-on reset, brownout protection, and software-execution integrity monitoring in harsh or battery-limited environments.

FAQ

What is the exact reset threshold voltage of ADM6320CZ27ARJZ-R7 and how does it vary with temperature?

The ADM6320CZ27ARJZ-R7 has a nominal reset threshold of 2.7 V, with tolerance of ±2.5% over the full industrial temperature range (−40°C to +85°C). At 25°C, the threshold is 2.7 V ±1.5%, and the temperature coefficient is 40 ppm/°C - meaning drift is under ±10 mV across the operating range. This ensures reliable detection of 3.3 V rail brownout while avoiding false triggers near nominal voltage.

Does ADM6320CZ27ARJZ-R7 require an external pull-up resistor on the RESET pin, and what value is recommended?

Yes, ADM6320CZ27ARJZ-R7 features an open-drain RESET output and requires an external pull-up resistor. A 10 kΩ resistor to a logic-compatible voltage rail (≤6 V) is recommended for most applications, as it ensures proper logic-high levels while limiting current draw during reset assertion. The resistor must meet the target MCU's VIH/VIL requirements and account for leakage (≤1 µA) and sink capability (≥1.2 mA at VCC ≥2.7 V).

How does the manual reset (MR) input behave on ADM6320CZ27ARJZ-R7, and what is its minimum pulse width?

The MR input on ADM6320CZ27ARJZ-R7 is active-low with an internal 52 kΩ pull-up resistor, eliminating need for external components. A low pulse ≥1 µs asserts RESET, and reset remains active for the full 140 ms timeout after MR returns high. Glitch rejection filters transients <100 ns, and the input threshold tracks VCC (0.3×VCC to 0.7×VCC when VTH < 4.0 V), ensuring robust operation across supply voltages.

What is the watchdog timeout behavior of ADM6320CZ27ARJZ-R7, and how is the timer cleared?

ADM6320CZ27ARJZ-R7 provides a 25.6 s typical watchdog timeout (Z-suffix). The timer is cleared on every logic transition (low-to-high or high-to-low) on the WDI pin, with minimum detectable pulse width of 50 ns. If no transition occurs within the timeout period, RESET is asserted. The timer is also automatically cleared during any reset event (VCC brownout or MR assertion), preventing spurious timeouts during recovery.

Can ADM6320CZ27ARJZ-R7 operate reliably at VCC = 1.2 V, and what is the RESET output behavior at that voltage?

Yes, ADM6320CZ27ARJZ-R7 guarantees valid RESET output down to VCC = 1 V. At VCC = 1.2 V, the open-drain RESET remains functional: it pulls low with ≤0.3 V saturation when sinking 100 µA, and exhibits ≤1 µA leakage when high. This ensures deterministic reset signaling even during deep brownout - critical for preventing MCU latch-up or undefined state in ultra-low-power systems.