Analog Devices Inc. ADM695AN

Overview

ADM695AN from Analog Devices is a 16-pin DIP microprocessor supervisory circuit providing precision reset generation (200 ms nominal), adjustable watchdog timeout (100 ms / 1.6 s / external), battery backup switchover (2.0–4.25 V VBATT), CE gating (5 ns propagation), and power-fail warning (1.3 V PFI threshold). It ensures reliable system startup, brownout recovery, and RAM data integrity in industrial embedded controllers.

For engineers reviewing the ADM695AN datasheet, ADM695AN pinout, ADM695AN application, or ADM695AN equivalent, key selection considerations include its 200 ms fixed/adjustable reset pulse width, dual-mode watchdog timer with post-reset 1.6 s safety window, VCC-down-to-1 V reset assertion, BATT ON base-drive capability for external PNP pass transistors, and integrated CEIN/CEOUT gating for CMOS RAM write protection.

Technical Context

The ADM695AN implements a dual-threshold voltage monitor: a 4.65 V ±73 mV reset comparator with 40 mV hysteresis and a 1.3 V ±50 mV power-fail comparator referenced to an internal bandgap. Its watchdog timer supports three modes-internal 100 ms/1.6 s selectable via OSC IN, or externally programmable via OSC IN clock input or capacitor-ensuring flexibility across boot-time and runtime supervision requirements.

Battery switchover uses a precision comparator with 70 mV turn-on and 50 mV turn-off thresholds, delivering <0.05 V dropout at 1 mA and sustaining 100 mA output drive from VCC or VBATT. The CE gating path features a 5 ns propagation delay and automatic high-Z override during reset, enabling fail-safe memory write blocking without external logic.

Key Specifications

Pinout & Package

ADM695AN is supplied in a 16-pin plastic DIP (N-16) package with 0.3-inch body width and 0.1-inch lead pitch. Pin 1 is located at the top-left corner when viewed from the top with the notch or dot oriented left.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX695CNG+ and TPS3823-50DBVR, the ADM695AN delivers comprehensive system supervision-including programmable timing, fail-safe memory gating, and high-current battery switchover-in a single 16-pin DIP, making it optimal for industrial and automotive applications demanding robust data retention and fault recovery.

Availability

ADM695AN is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive telematics modules, medical handheld diagnostics, smart energy meters, and intelligent instrumentation requiring stable component supply and long-term lifecycle support.

Supply support for ADM695AN 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.

The ADM690–ADM695 family was designed specifically for microprocessor system supervision, integrating reset generation, battery backup control, watchdog timing, and memory protection into single-chip solutions for reliability-critical embedded applications.

FAQ

What is the guaranteed reset voltage threshold range for the ADM695AN?

The ADM695AN has a guaranteed reset voltage threshold range of 4.5 V to 4.73 V at +25°C, with typical value 4.65 V. This specification ensures compatibility with standard +5 V ±5% power supplies and guarantees reliable reset assertion during brownout conditions across the full –40°C to +85°C industrial temperature range.

How does the ADM695AN handle battery switchover during power failure?

The ADM695AN compares VCC and VBATT using precision comparators with 70 mV turn-on and 50 mV turn-off thresholds, providing 20 mV hysteresis to prevent oscillation. When VCC drops below VBATT minus 50 mV, it seamlessly switches VOUT from VCC to VBATT with <0.05 V dropout at 1 mA, sustaining up to 100 mA output while drawing only 1 µA in backup mode.

Can the reset pulse width of the ADM695AN be adjusted, and how?

Yes, the ADM695AN reset pulse width is adjustable via OSC SEL and OSC IN pins. With OSC SEL high or floating, connecting OSC IN high selects 200 ms; connecting OSC IN low selects 50 ms. With OSC SEL low, an external capacitor on OSC IN sets reset width as 130 ms × C/47 pF, or an external clock input configures it to 512 cycles, enabling precise tailoring to processor boot requirements.

What is the function of the BATT ON pin on the ADM695AN, and what load can it drive?

The BATT ON pin on the ADM695AN is an active-high open-collector output that asserts when VOUT is sourced from VBATT. It can sink up to 35 mA and is designed to directly drive the base of an external PNP pass transistor, enabling VOUT current extension beyond the internal 100 mA limit-critical for high-capacity RAM or RTC backup applications.

Does the ADM695AN provide both active-high and active-low reset outputs?

Yes, the ADM695AN provides dual reset outputs: Pin 8 (RESET) is active-low, and Pin 13 (RESET) is active-high-the logical inverse. This allows direct interface with microprocessors requiring either polarity without external inverters, simplifying board design and improving noise immunity in mixed-signaling systems.