Analog Devices Inc. ADM8693ARU

Overview

ADM8693ARU from Analog Devices is a microprocessor supervisory circuit providing power-on reset, battery backup switchover, watchdog timer, and power-fail detection in a single 16-lead TSSOP package. It asserts active-low RESET down to VCC = 1 V, delivers up to 100 mA at VOUT, features 4.65 V reset threshold with 40 mV hysteresis, and supports 100 ms / 1.6 s watchdog timeout selection - used in industrial controllers and battery-backed instrumentation.

For engineers reviewing the ADM8693ARU datasheet, ADM8693ARU pinout, ADM8693ARU application, or ADM8693ARU equivalent, key selection criteria include guaranteed reset assertion below 1 V VCC, integrated battery switchover with 70 mV switchover hysteresis, 3 ns CE gating delay, 1.3 V PFI comparator for power-fail warning, and compatibility with 5 V ±5% supplies.

Technical Context

The ADM8693ARU implements a dual-voltage switchover architecture using internal PMOS (0.7 Ω) and NMOS (7 Ω) switches to route VCC or VBATT to VOUT based on relative voltage levels, with 70 mV turn-on and 50 mV turn-off thresholds. Its reset generator uses a precision 4.65 V bandgap comparator with 40 mV hysteresis and guarantees operation down to 1 V VCC.

A three-level WDI input monitors microprocessor activity with configurable timeout (100 ms or 1.6 s), while the PFI/PFO comparator provides 1.3 V power-fail detection independent of VCC regulation status. The device includes dedicated BATT ON and LOW LINE outputs for external transistor drive and system-level brownout signaling.

Key Specifications

Pinout & Package

ADM8693ARU is housed in a 16-lead TSSOP package (4.4 mm × 5.0 mm, 0.65 mm pitch), compatible with industry-standard reflow profiles and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX691ACPE+ and TPS3823DBVT, the ADM8693ARU uniquely integrates battery switchover, dual reset outputs, CE gating, and PFI detection in one 16-TSSOP device - eliminating four discrete components in 5 V microprocessor systems requiring data integrity during power interruption.

Availability

ADM8693ARU is available at Aetrix Electronics and suitable for industrial controllers, automotive telematics modules, medical infusion pumps, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADM8693ARU 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-based systems needing integrated power monitoring, battery backup, and fault recovery - targeting applications where data integrity and deterministic reset behavior are mission-critical.

FAQ

What is the minimum VCC voltage at which ADM8693ARU guarantees RESET assertion?

The ADM8693ARU guarantees active-low RESET assertion down to VCC = 1 V, enabling fail-safe microprocessor hold-down during severe brownout conditions. This specification is verified across the full industrial temperature range (−40°C to +85°C) and is independent of VBATT voltage. The ADM8693ARU maintains RESET functionality even when VCC collapses below typical logic thresholds, ensuring deterministic system shutdown in critical applications.

How does ADM8693ARU handle battery switchover between VCC and VBATT?

The ADM8693ARU uses internal MOSFET switches to automatically route the higher of VCC or VBATT to VOUT. Switchover occurs at VCC − VBATT = +70 mV (rising) and +50 mV (falling), providing 20 mV hysteresis to prevent chatter. In normal operation, the 0.7 Ω PMOS switch delivers up to 100 mA from VCC; during backup, the 7 Ω NMOS switch supplies low-current loads from VBATT (2.0–4.25 V) with only 0.4 μA quiescent current.

Can ADM8693ARU monitor non-5 V power rails such as 3.3 V or battery voltage?

Yes - the ADM8693ARU's PFI input accepts any voltage referenced to GND and compares it to a precise 1.3 V internal threshold. By scaling a 3.3 V rail with a resistor divider (e.g., 1.5 MΩ/1.0 MΩ), PFI detects drops below 3.1 V. Similarly, direct connection of a lithium coin cell (2.0–3.6 V) to PFI enables low-battery warning at ~2.3 V, leveraging the same 1.3 V comparator with predictable hysteresis.

What is the function of the CEIN and CEOUT pins on ADM8693ARU?

CEIN accepts the microcontroller's chip-enable or write-enable signal; CEOUT replicates it with 3 ns propagation delay when VCC ≥ 4.65 V, but forces high during brownout or reset. This blocks memory writes to battery-backed CMOS RAM whenever VCC is invalid, preventing partial writes and data corruption. CEOUT drives RAM CE/WE inputs directly - no external logic required - and supports both active-high and active-low memory interfaces.

Does ADM8693ARU support both active-low and active-high reset outputs simultaneously?

Yes - ADM8693ARU provides two independent reset outputs: Pin 15 (RESET) is active-low, and Pin 16 (RESET) is active-high (complementary). Both are guaranteed functional down to VCC = 1 V and share identical timing (50 ms pulse width). This dual-output architecture eliminates level shifters or inverters when interfacing with heterogeneous processor families - for example, ARM Cortex-M cores (active-low) and legacy 8051 derivatives (active-high) on the same board.