Analog Devices Inc. ADM695AR

Overview

ADM695AR from Analog Devices is a 16-pin SOIC microprocessor supervisory circuit providing precision reset generation (200 ms nominal), battery backup switchover, adjustable watchdog timer (100 ms / 1.6 s / user-configurable), power-fail warning (1.3 V threshold), and CE signal gating with 5 ns propagation delay. It asserts RESET down to VCC = 1 V and supports up to 100 mA VOUT drive for CMOS RAM in industrial systems.

For engineers reviewing the ADM695AR datasheet, ADM695AR pinout, ADM695AR application, or ADM695AR equivalent, this device delivers verified low-power supervision (600 nA standby), guaranteed reset assertion at 1 V VCC, dual-mode watchdog timing, and integrated battery switchover with 70 mV turn-on hysteresis - critical for reliable embedded controller and automotive power management design.

Technical Context

The ADM695AR implements a dual-threshold voltage monitor: a 4.65 V ±130 mV reset comparator with 40 mV hysteresis and a separate 1.3 V ±50 mV power-fail comparator. Its watchdog timer uses either an internal oscillator (10.24 kHz) or external clock/capacitor input to generate configurable timeout periods.

It integrates three independent switching paths: a 1.5 Ω PMOS VCC-to-VOUT switch (100 mA), a 20 Ω MOSFET VBATT-to-VOUT switch (250 µA load), and a BATT ON output capable of sinking 35 mA to drive external PNP transistors - all operating with validated behavior in battery-backup mode per Table II.

Key Specifications

Pinout & Package

ADM695AR is housed in a 16-lead SOIC (R-16) package with 1.27 mm pitch, JEDEC MS-012AC 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 MAX695CPE+ and TPS3823MPW, the ADM695AR uniquely integrates battery switchover control, CE signal gating, and dual-comparator power-fail warning in a single SOIC package - enabling compact, high-integrity supervision without external components or layout compromises.

Availability

ADM695AR is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive telematics modules, medical diagnostic instruments, and smart energy meters requiring stable component supply with guaranteed long-term availability.

Supply support for ADM695AR 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 ADM690–ADM695 family was designed specifically for robust microprocessor system supervision - integrating reset, watchdog, battery switchover, power-fail warning, and memory protection in a single IC to reduce board space and improve system reliability.

FAQ

What is the guaranteed minimum operating VCC for reset assertion in ADM695AR?

The ADM695AR guarantees RESET assertion down to VCC = 1 V, ensuring the microprocessor remains held in reset during deep brownout conditions. This specification is validated across the full –40°C to +85°C temperature range and is independent of battery voltage. The internal reset comparator continues functioning reliably at this level, making ADM695AR suitable for applications with unstable or marginal power supplies where other supervisors may release reset prematurely.

How does ADM695AR handle battery switchover hysteresis, and why is it important?

The ADM695AR uses 70 mV hysteresis on power-up (VCC – VBATT ≥ 70 mV to engage VBATT) and 50 mV on power-down (VCC – VBATT ≤ 50 mV to disengage VBATT), resulting in 20 mV total hysteresis. This prevents rapid toggling between VCC and VBATT when supply voltages are nearly equal - a common cause of RAM corruption or logic glitches in systems with slow-decaying rails. The hysteresis is implemented in dedicated comparator circuitry and is specified in the Absolute Maximum Ratings table under "Battery Switchover Hysteresis".

Can ADM695AR drive more than 100 mA to VOUT, and if so, how?

Yes - ADM695AR supports >100 mA VOUT drive using its BATT ON output to control an external PNP transistor, as shown in Figure 17 of the datasheet. The BATT ON pin sinks 35 mA and can directly drive the base of a PNP pass transistor (e.g., MMBT3906) placed between VBATT and VOUT. This configuration maintains low dropout voltage while scaling current capacity beyond the internal 100 mA limit, preserving data integrity in high-current RAM or real-time clock applications.

What is the function of the LOW LINE output on ADM695AR, and how does it differ from RESET?

LOW LINE is an active-low, immediate-response output that goes low the instant VCC falls below the 4.65 V reset threshold - with no delay - and returns high immediately upon VCC rising above threshold. In contrast, RESET has a fixed 200 ms pulse width after recovery and remains asserted during brownout. LOW LINE is intended for real-time voltage monitoring or fast-acting auxiliary circuit control, while RESET serves the microprocessor's reset pin with guaranteed timing compliance.

Does ADM695AR support both active-high and active-low reset outputs, and how are they used?

Yes - ADM695AR provides both RESET (active-low) and RESET (active-high) outputs. The active-high RESET is the logical inverse of RESET and is explicitly intended for microprocessors requiring active-high reset assertion without external inversion. Both outputs share the same timing and threshold behavior. This dual-output architecture eliminates the need for discrete inverters or pull-up resistors in mixed-signaling systems, simplifying design and reducing BOM count.