Analog Devices Inc. ADM693SQ

Overview

ADM693SQ from Analog Devices is a high-reliability microprocessor supervisory circuit designed for extended-temperature industrial and automotive applications. It provides precision 4.4 V reset threshold, adjustable 50 ms/200 ms reset timeout, dual-mode watchdog timer (100 ms or 1.6 s), automatic battery backup switchover (VCC/VBATT), and power-fail warning (1.3 V PFI comparator). It operates across –55°C to +125°C and drives up to 100 mA on VOUT for CMOS RAM backup in mission-critical embedded controllers.

For engineers reviewing the ADM693SQ datasheet, ADM693SQ pinout, ADM693SQ application, or ADM693SQ equivalent, this page delivers verified functional specifications, validated 16-pin SOIC pin mapping, real-world use cases in automotive ECUs and ruggedized instrumentation, and two confirmed alternative parts with documented timing and voltage threshold differences.

Technical Context

The ADM693SQ integrates five core supervisory functions in a single chip: (1) precision reset generation with 40 mV hysteresis and guaranteed operation down to VCC = 1 V; (2) battery switchover with 70 mV turn-on and 50 mV turn-off thresholds and <20 Ω backup-path resistance; (3) configurable watchdog using internal oscillator or external capacitor/clock; (4) active-low PFO output triggered by 1.3 V PFI comparator with <1 µs response; and (5) CEIN/CEOUT gating with 5 ns propagation delay and automatic high-Z override during brownout.

Its OSC SEL and OSC IN pins enable three distinct timing configurations: fixed 100 ms/1.6 s watchdog with internal oscillator, or user-adjustable reset/watchdog periods via external capacitor (e.g., 47 pF → 260 ms reset) or clock input (e.g., 4096 cycles). All logic outputs-RESET, WDO, BATT ON, LOW LINE, CEOUT, and PFO-feature rail-to-rail drive capability and are fully specified over the full –55°C to +125°C range.

Key Specifications

Pinout & Package

ADM693SQ is housed in a 16-pin plastic small-outline integrated circuit (SOIC) package (R-16), measuring 10.3 mm × 7.5 mm × 2.35 mm, with standard 1.27 mm pitch and gull-wing leads. The package is RoHS-compliant and rated for reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM693AR, the ADM693SQ adds guaranteed operation at –55°C and +125°C with no change to timing or electrical specs; versus MAX693ACPE+, it retains CEOUT-based memory protection and OSC IN configurability-critical for safety-critical firmware integrity.

Availability

ADM693SQ is available at Aetrix Electronics and suitable for automotive engine control units, industrial PLCs, aerospace data loggers, and ruggedized handheld instruments requiring stable component supply across extreme temperature profiles and long production lifecycles.

Supply support for ADM693SQ 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, serving industrial, automotive, communications, and healthcare markets since 1965.

The ADM690–ADM695 family was engineered specifically for microprocessor system supervision-integrating reset, watchdog, battery switchover, power-fail warning, and memory gating into a single IC to reduce system-level complexity and improve reliability in harsh environments.

FAQ

What is the guaranteed reset voltage threshold for ADM693SQ?

The ADM693SQ has a guaranteed reset voltage threshold of 4.25 V minimum to 4.48 V maximum, with a typical value of 4.4 V. This specification is fully tested and warranted across the entire –55°C to +125°C operating temperature range, ensuring compatibility with ±10% 5 V power supplies in demanding automotive and industrial applications.

Does ADM693SQ support adjustable reset timeout, and how is it configured?

Yes, ADM693SQ supports adjustable reset timeout via its OSC SEL and OSC IN pins. With OSC SEL high or floating, connecting OSC IN to GND selects 50 ms timeout, while leaving OSC IN open selects 200 ms. With OSC SEL low, an external capacitor (e.g., 47 pF) on OSC IN yields ~260 ms reset pulse width, scalable linearly with capacitance.

Can ADM693SQ drive external circuitry directly, and what are its output current limits?

Yes, ADM693SQ provides multiple buffered outputs capable of direct drive: VOUT supplies up to 100 mA at <0.5 V dropout; BATT ON sinks 35 mA and can drive a PNP transistor base; RESET, WDO, PFO, and CEOUT each sink ≥1.6 mA or source ≥1 µA. All outputs are rail-to-rail and fully characterized over temperature.

How does ADM693SQ handle battery backup switchover during power failure?

ADM693SQ continuously compares VCC and VBATT, switching VOUT to VBATT when VCC falls below VBATT − 50 mV (power-down) and reverting to VCC when VCC rises above VBATT + 70 mV (power-up). This 20 mV hysteresis prevents oscillation near the switchover point, and the internal 20 Ω PMOS switch ensures minimal voltage drop in backup mode.

Is ADM693SQ pin-compatible with other members of the ADM690–ADM695 family?

ADM693SQ shares the same 16-pin SOIC (R-16) pinout with ADM691, ADM695, and their Q-16/DIP variants, but differs functionally from 8-pin members (e.g., ADM692SQ). Critical distinctions include presence of CEIN/CEOUT, RESET, OSC IN, and OSC SEL pins-absent in 8-pin versions-making it incompatible with those packages without board redesign.