Analog Devices Inc. ADM13305-18ARZ

Overview

ADM13305-18ARZ from Analog Devices is a dual-voltage supervisor IC designed to monitor 3.3 V and 1.8 V power rails in microprocessor-based systems, providing both active-high and active-low reset outputs with 140 ms minimum timeout, 1.6 sec watchdog timer, and operation down to VDD ≥ 1.1 V. It supports industrial temperature range (−40°C to +85°C) and consumes only 40 μA typical supply current.

For engineers reviewing the ADM13305-18ARZ datasheet, ADM13305-18ARZ pinout, ADM13305-18ARZ application, or ADM13305-18ARZ equivalent, key selection considerations include its fixed 2.93 V / 1.68 V undervoltage thresholds, push-pull reset drive capability, watchdog input (WDI) sensitivity, manual reset (MR) timing behavior, and SOIC_N package compatibility for space-constrained embedded designs.

Technical Context

The ADM13305-18ARZ integrates two independent voltage monitoring channels with pretrimmed thresholds (2.93 V for SENSE1, 1.68 V for SENSE2), hysteresis of 30 mV and 20 mV respectively, and transition detection logic that asserts RESET when either input falls below its falling threshold (VIT−). Its internal oscillator drives both the 140 ms reset timeout and 1.6 sec watchdog timer.

Reset assertion is guaranteed down to VDD = 1.1 V; both RESET and RESET outputs are push-pull with VOH ≥ VDD − 0.4 V at 3 mA load and VOL ≤ 0.4 V at same condition. The WDI pin accepts logic transitions to clear the watchdog, and MR provides asynchronous manual reset with 140–280 ms deassertion delay.

Key Specifications

Pinout & Package

ADM13305-18ARZ is housed in an 8-lead narrow-body SOIC (SOIC_N, package code R-8), JEDEC MS-012-AA compliant, with 1.27 mm lead pitch and 5.00 mm × 4.00 mm body dimensions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply supervision applications.

Compared with MAX6816EUT+T and TPS3808G18DBVR, the ADM13305-18ARZ uniquely delivers integrated dual-threshold supervision plus watchdog functionality in a single SOIC-8 package-reducing component count, PCB area, and qualification effort for multi-rail embedded systems.

Availability

ADM13305-18ARZ is available at Aetrix Electronics and suitable for industrial PLCs, wireless transceivers, notebook embedded controllers, and DSP-based instrumentation requiring stable component supply and long-term manufacturability.

Supply support for ADM13305-18ARZ 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 precision instrumentation, industrial automation, communications, and aerospace markets.

The ADM13305 family was engineered specifically for robust power-supply supervision in microprocessor and DSP systems-emphasizing low quiescent current, guaranteed reset at low VDD, and integrated watchdog reliability in harsh operating environments.

FAQ

What is the exact undervoltage threshold for each sense input on the ADM13305-18ARZ?

The ADM13305-18ARZ has factory-trimmed thresholds: SENSE1 monitors at 2.93 V (range 2.86–3.02 V over temperature), and SENSE2 at 1.68 V (1.64–1.73 V). These values are specified in Table 1 of the datasheet and apply directly to the ADM13305-18ARZ without external components.

Does the ADM13305-18ARZ require external pull-up resistors on its RESET and RESET outputs?

No. The ADM13305-18ARZ features push-pull output drivers on both RESET and RESET pins, eliminating the need for external pull-up resistors. Each output can source up to 5 mA and sink up to 5 mA, supporting direct connection to processor reset inputs.

Can the watchdog timer in the ADM13305-18ARZ be disabled, and how?

Yes. The watchdog timer in the ADM13305-18ARZ is disabled by leaving the WDI pin unconnected (floating). No external pull-up or pull-down is required-open-circuit WDI halts watchdog counting and prevents spurious resets.

What is the minimum VDD voltage at which the ADM13305-18ARZ guarantees valid RESET assertion?

The ADM13305-18ARZ guarantees RESET assertion functionality down to VDD = 1.1 V. This allows early detection of supply collapse before the monitored rails fall, providing critical headroom for safe system shutdown or state capture.

Is the ADM13305-18ARZ pin-compatible with other variants in the ADM13305 family?

Yes. All ADM13305 variants-including ADM13305-18ARZ, ADM13305-25ARZ, and ADM13305-33ARZ-share identical 8-lead SOIC_N (R-8) pinout and electrical interface. Only the internal threshold configurations differ; no PCB layout change is needed when substituting within the family.