Analog Devices Inc. ADM8693ARW

Overview

ADM8693ARW from Analog Devices is a 16-lead TSSOP microprocessor supervisory circuit providing precision reset generation (4.4 V threshold), adjustable watchdog timeout (100 ms / 1.6 s / external), battery backup switchover (VCC/VBATT to VOUT), CE gating (3 ns propagation), and power-fail detection (1.3 V PFI comparator) for embedded systems requiring reliable power sequencing and data integrity in industrial controllers.

For engineers reviewing the ADM8693ARW datasheet, ADM8693ARW pinout, ADM8693ARW application, or ADM8693ARW equivalent, this page delivers verified functional specifications, real-world timing behavior, battery switchover hysteresis (20 mV), CEOUT logic control under brownout, and design-meaningful parameter values - all confirmed for the ADM8693ARW variant specifically.

Technical Context

The ADM8693ARW integrates a dual-mode oscillator (internal 10.24 kHz or external clock/capacitor) that independently controls both reset pulse width (50 ms or adjustable) and watchdog timeout (100 ms/1.6 s/adjustable). Its battery switchover uses PMOS/NMOS switching with 70 mV turn-on and 50 mV turn-off thresholds, ensuring stable VOUT sourcing up to 100 mA from VCC or 250 µA from VBATT.

It features three-level WDI input (internally biased to 38% VCC, ~5 MΩ impedance), active-high RESET complement output, and dedicated BATT ON and LOW LINE status outputs. CEIN-to-CEOUT gating enforces write protection by forcing CEOUT high during VCC undervoltage, independent of CEIN state.

Key Specifications

Pinout & Package

ADM8693ARW is housed in a 16-lead TSSOP package (RU-16), pin-compatible with 16-lead PDIP and SOIC_N variants. Pin functions are validated per Analog Devices Rev. B datasheet Figures 4 and Table 4.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM8691ARW and MAX693CPE+, the ADM8693ARW uniquely combines 4.4 V reset threshold for wide 5 V tolerance, CEOUT write protection, and PFI-based early power-fail detection - making it the only option supporting full data integrity architecture in compact TSSOP form.

Availability

ADM8693ARW is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical infusion pumps, and smart energy meters requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for ADM8693ARW 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, founded in 1965 and headquartered in Wilmington, MA.

The ADM869x family was designed specifically for microprocessor system reliability - integrating reset, watchdog, battery switchover, write protection, and power-fail detection into single-chip solutions for industrial, automotive, and medical embedded applications.

FAQ

What is the exact reset voltage threshold for ADM8693ARW, and how does it vary with temperature?

The ADM8693ARW has a nominal reset voltage threshold of 4.4 V, with guaranteed min/max values of 4.25 V and 4.48 V over the full industrial temperature range (−40°C to +85°C). Figure 10 in the datasheet shows typical variation of ±12 mV from 25°C across −40°C to +125°C, confirming stability within specification limits. This 4.4 V threshold makes ADM8693ARW compatible with 5 V ±10% power supplies, unlike the 4.65 V variants.

Does ADM8693ARW support adjustable reset pulse width, and how is it configured?

Yes, ADM8693ARW supports adjustable reset pulse width via the OSC SEL and OSC IN pins. With OSC SEL high or floating, reset width is fixed at 50 ms; with OSC SEL low, connecting a capacitor (e.g., 47 pF) to OSC IN yields ~50 ms × C/47 pF, while an external clock gives 512 cycles (short) or 2048 cycles (long). This configurability allows tuning to match specific microprocessor startup timing requirements without board redesign.

How does the battery switchover function in ADM8693ARW, and what is its hysteresis?

ADM8693ARW switches VOUT between VCC and VBATT based on relative voltage: VOUT connects to VBATT when VCC falls 50 mV below VBATT (power-down), and reconnects to VCC when VCC rises 70 mV above VBATT (power-up). This 20 mV hysteresis prevents oscillation during slow VCC decay near battery voltage. The switchover is fully automatic, requires no external components, and maintains VOUT regulation to within 2.5 mV at 1 mA load.

Can ADM8693ARW drive CMOS RAM directly, and what is its maximum VOUT current capability?

Yes, ADM8693ARW can drive CMOS RAM directly: VOUT delivers up to 100 mA from VCC (with 0.7 Ω R_DS(on)) and 250 µA from VBATT (with 7 Ω R_DS(on)). For peak RAM currents exceeding 100 mA, a bypass capacitor (≥0.1 µF) is recommended at VOUT. If continuous >100 mA is required, the BATT ON output can drive an external PNP transistor - a capability not present in 8-lead variants like ADM8692.

What is the purpose of the CEIN and CEOUT pins on ADM8693ARW, and how do they protect memory?

The CEIN and CEOUT pins implement hardware write protection: CEOUT is a buffered, 3 ns-delayed replica of CEIN during normal operation, but is forced high whenever VCC falls below 4.4 V or during reset - regardless of CEIN state. This ensures CMOS RAM or EEPROM write inputs are disabled during brownout, preventing data corruption. CEOUT directly drives CE/CS/WRITE pins, eliminating need for external logic or pull-ups.