Analog Devices Inc. ADM696SQ

Overview

ADM696SQ from Analog Devices is a high-reliability microprocessor supervisory circuit with battery backup switching, adjustable low-line monitoring (1.3 V threshold), watchdog timer (100 ms / 1.6 s selectable), and power-fail detection - designed for critical embedded systems operating from –55°C to +125°C. It asserts RESET down to 1 V VCC and delivers up to 100 mA from VOUT during main supply operation.

For engineers reviewing the ADM696SQ datasheet, ADM696SQ pinout, ADM696SQ application, or ADM696SQ equivalent, this page provides verified functional identity, temperature-qualified timing behavior, battery switchover hysteresis (50 mV/70 mV), reset timeout (35–70 ms), and real-world use cases in aerospace-grade instrumentation and extended-temperature industrial controllers.

Technical Context

The ADM696SQ integrates a precision 1.3 V reference comparator for LLIN and PFI inputs, a dual-mode watchdog timer (internal oscillator or external clock/capacitor), and a PMOS-based battery switchover circuit with 1.5 Ω on-resistance. Its RESET generator guarantees assertion at VCC ≥ 1 V and holds active for 50 ms after LLIN recovery.

It features three-level WDI input (internally biased to 38% VCC, ~125 kΩ impedance), BATT ON output capable of sinking 7 mA to drive external PNP transistors, and automatic disable of PFI comparator during battery backup mode - all implemented in an advanced epitaxial CMOS process delivering 5 mW typical power dissipation.

Key Specifications

Pinout & Package

ADM696SQ is supplied in a 16-pin CERDIP (Q-16) package with 0.3-inch wide body, hermetically sealed for high-reliability environments. Pin spacing is 0.1 inch; lead finish is tin-lead.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX696CPE+ and TPS3823MPWPT, the ADM696SQ uniquely combines extended-temperature operation, integrated battery switchover, adjustable watchdog, and dual-comparator monitoring - making it irreplaceable in mission-critical systems where component count, reliability, and thermal range are constrained.

Availability

ADM696SQ is available at Aetrix Electronics and suitable for aerospace instrumentation, downhole sensors, military vehicle computing, and extended-temperature industrial controllers requiring stable component supply across full military temperature ranges.

Supply support for ADM696SQ 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, and defense markets since 1965.

The ADM696SQ belongs to Analog Devices' microprocessor supervisory product line, engineered specifically for high-reliability embedded systems demanding guaranteed reset behavior, battery-backed memory integrity, and operation across extreme environmental conditions.

FAQ

What is the maximum continuous output current supported by ADM696SQ's VOUT pin?

The ADM696SQ VOUT pin delivers up to 100 mA continuously when powered from VCC, with a typical voltage drop of 0.25 V at that load. In battery backup mode, VOUT supplies up to 250 µA while maintaining VBATT – 0.02 V. For loads exceeding 100 mA, the BATT ON output can drive an external PNP transistor - a design approach validated in Analog Devices' Figure 14 application circuit. This capability is intrinsic to the ADM696SQ's internal PMOS switch architecture.

Does ADM696SQ support watchdog timer configuration via external components?

Yes, the ADM696SQ supports external watchdog configuration through two methods: applying a clock signal (0–250 kHz) to OSC IN with OSC SEL grounded, or connecting a capacitor (e.g., 47 pF) between OSC IN and GND while OSC SEL is low. Table I in the datasheet confirms 4096 cycles (long) or 1024 cycles (short) timeout options with external clock, and scalable timing (e.g., 1.6 s × C/47 pF) with capacitor. These modes are fully functional across the –55°C to +125°C range of the ADM696SQ.

How does ADM696SQ behave during battery backup mode?

In battery backup mode (VCC = 0 V, VBATT > 2.0 V), the ADM696SQ routes VBATT to VOUT via a low-leakage MOSFET, asserts RESET low, sets LOW LINE low, drives BATT ON high, and forces PFO low. WDI, OSC IN, and OSC SEL are internally disconnected to minimize current draw - resulting in just 0.6 µA typical supply current. This behavior is explicitly defined in Table II of the ADM696SQ datasheet and ensures deterministic, low-power memory retention without software intervention.

What is the reset timeout accuracy of ADM696SQ over temperature?

The ADM696SQ reset timeout varies from 35 ms (min) to 70 ms (max) at +25°C with OSC SEL high, and exhibits ±10% variation across –55°C to +125°C per Figure 11. This 50 ms nominal delay (typical) is generated by the internal oscillator and remains stable due to the 1.3 V bandgap reference - critical for ensuring reliable processor initialization timing in extended-temperature deployments of the ADM696SQ.

Can ADM696SQ monitor multiple supply rails simultaneously?

The ADM696SQ directly monitors one primary supply via LLIN (1.3 V threshold) and a secondary supply or battery via PFI (also 1.3 V threshold). While it does not natively support multi-rail thresholds, external resistor dividers allow scaling of any supply (e.g., 12 V, 3.3 V) to fit within the 1.3 V comparator window. The PFI–LLIN threshold difference is tightly controlled (±15 mV), enabling coordinated power-fail and brownout detection - a capability confirmed in the ADM696SQ's General Description and Applications Information sections.