Analog Devices Inc. ADM8692ARNZ

Overview

ADM8692ARNZ from Analog Devices is a microprocessor supervisory circuit providing power-on reset, battery backup switchover, watchdog timer, and power-fail detection in a single 8-lead TSSOP package. It asserts active-low RESET down to VCC = 1 V, features a 4.40 V reset threshold, 1.6 s fixed watchdog timeout, and automatic VCC/VBATT switching with 0.7 Ω on-resistance for up to 100 mA VOUT drive - used in industrial controllers requiring reliable brownout recovery and nonvolatile memory retention.

For engineers reviewing the ADM8692ARNZ datasheet, ADM8692ARNZ pinout, ADM8692ARNZ application, or ADM8692ARNZ equivalent, key selection criteria include its fixed 4.40 V reset threshold (±5% over temperature), guaranteed 50 ms RESET pulse width, 400 nA standby current, and compatibility with 5 V ±10% supplies - critical for legacy embedded systems where deterministic reset timing and low-power backup are mandatory.

Technical Context

The ADM8692ARNZ implements a dual-threshold voltage monitor with 40 mV hysteresis and guarantees RESET assertion at VCC ≥ 1 V. Its internal PMOS switch enables seamless transition between VCC and VBATT inputs to VOUT, maintaining CMOS RAM supply during main power loss.

It integrates a fixed-period watchdog timer (1.6 s nominal) triggered by WDI transitions, with no external components required. The PFI/PFO comparator provides early power-fail warning via a precision 1.3 V reference, independent of VCC regulation status.

Key Specifications

Pinout & Package

ADM8692ARNZ is housed in an 8-lead TSSOP package (3.0 mm × 4.4 mm, 0.65 mm pitch), RoHS-compliant and rated for −40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX692AESA+ and TPS3823-44DBVR, ADM8692ARNZ uniquely integrates battery switchover, power-fail warning, and 1 V reset operation in one 8-pin TSSOP - eliminating board space and BOM count for discrete backup solutions while meeting stringent industrial brownout requirements.

Availability

ADM8692ARNZ is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, and medical infusion pumps requiring stable component supply with long-term lifecycle support.

Supply support for ADM8692ARNZ 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 since 1965.

The ADM869x family was designed specifically for microprocessor system supervision - integrating reset generation, battery backup, watchdog timing, and power-fail detection into compact, low-power packages for space-constrained embedded applications.

FAQ

What is the guaranteed reset voltage threshold for ADM8692ARNZ?

The ADM8692ARNZ has a guaranteed reset voltage threshold of 4.25 V minimum to 4.48 V maximum, with a typical value of 4.40 V. This threshold is specified over the full industrial temperature range (−40°C to +85°C) and enables compatibility with 5 V ±10% power supplies. The 40 mV hysteresis prevents chatter during slow VCC transitions, and RESET remains asserted down to VCC = 1 V to ensure robust brownout handling in the ADM8692ARNZ.

Does ADM8692ARNZ support adjustable watchdog timeout periods?

No, ADM8692ARNZ does not support adjustable watchdog timeout. It features a fixed 1.6 s nominal watchdog timeout period (1.0–2.25 s over temperature), with no external components or pin strapping options for modification. Unlike the 16-pin ADM8691/ADM8693/ADM8695 variants, ADM8692ARNZ lacks OSC SEL and OSC IN pins required for adjustment. The watchdog timer resets on every WDI transition and asserts RESET if unattended beyond the fixed timeout - a design choice simplifying qualification for safety-critical ADM8692ARNZ deployments.

What is the maximum continuous output current from VOUT on ADM8692ARNZ?

The ADM8692ARNZ delivers up to 100 mA continuously from its VOUT pin when powered from VCC, enabled by an internal 0.7 Ω PMOS switch. Under battery backup conditions (VBATT → VOUT), it supports 250 µA continuous load with <5 mV dropout. For loads exceeding 100 mA, an external PNP transistor driven by BATT ON is required - though ADM8692ARNZ does not include the BATT ON pin (present only on 16-pin variants). Therefore, VOUT current capability in ADM8692ARNZ is strictly limited to 100 mA from VCC and low-µA levels from VBATT.

Can ADM8692ARNZ monitor a 3.3 V supply using the PFI input?

Yes, ADM8692ARNZ can monitor a 3.3 V supply using the PFI input by scaling it with a resistor divider to match the 1.30 V internal reference. With PFI threshold tolerance of ±25 mV over temperature, a 2:1 divider (e.g., 20 kΩ top, 10 kΩ bottom) yields 1.1 V at PFI for 3.3 V supply - within detectable range. The PFI input draws only ±0.01 µA, minimizing divider error. When PFI falls below 1.3 V, PFO goes low, providing early warning before VCC crosses the 4.40 V reset threshold - a key diagnostic function in ADM8692ARNZ-based systems.

Is ADM8692ARNZ pin-compatible with ADM8690 or ADM8691?

ADM8692ARNZ shares identical 8-lead TSSOP pinout with ADM8690 but is not pin-compatible with ADM8691, which uses a 16-lead package with additional pins (CEIN, CEOUT, WDO, OSC IN, etc.). While ADM8692ARNZ and ADM8690 both offer 8-pin PDIP/TSSOP variants with matching pin functions (PFO, WDI, RESET, GND, PFI, VOUT, VCC, VBATT), their reset thresholds differ (4.40 V vs. 4.65 V), making them functionally distinct. Substitution requires validation of supply tolerance margins - ADM8692ARNZ is not a drop-in replacement for ADM8690 without schematic review.