Analog Devices Inc. ADM706SAN

Overview

ADM706SAN from Analog Devices is a 3 V microprocessor supervisory circuit with active-low reset output, 2.93 V reset threshold, 200 ms reset pulse width, 100 µA quiescent current, and integrated watchdog timer. It monitors power-up, brownout, and power-down conditions in embedded microcontroller systems requiring reliable reset assertion down to VCC = 1 V.

For engineers reviewing the ADM706SAN datasheet, ADM706SAN pinout, ADM706SAN application, or ADM706SAN equivalent, key selection considerations include its precise 2.93 V supply monitoring threshold, debounced manual reset input (MR), independent 1.6 s watchdog timeout, power-fail comparator (PFI/PFO), and compatibility with 3 V/3.3 V systems.

Technical Context

The ADM706SAN implements a precision voltage monitor with internal 2.93 V reference and 20 mV hysteresis, ensuring stable reset assertion during supply transients. Its watchdog circuit detects microprocessor stall via WDI transitions and asserts WDO low after 1.6 s of inactivity.

It integrates a 1.25 V power-fail comparator (PFI/PFO) for early warning of supply collapse and supports manual reset via internally debounced MR input with 70 µA pull-up. RESET remains valid down to VCC = 1 V, guaranteeing controlled shutdown sequencing.

Key Specifications

Pinout & Package

ADM706SAN is housed in an 8-lead narrow-body PDIP (N-8) package per JEDEC MS-001, with 0.300-inch body width and 0.100-inch lead pitch. Pin 1 is marked by a notch or dot; leads are tin-lead plated.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706SASA+, ADM706SAN offers identical supervision functionality with Analog Devices' qualification and long-term supply assurance; compared with TPS3808G33DBVR, ADM706SAN provides full feature parity including watchdog and dual-supply monitoring essential for safety-critical embedded systems.

Availability

ADM706SAN is available at Aetrix Electronics and suitable for industrial control PLCs, portable medical devices, network edge routers, and smart energy meters requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for ADM706SAN 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, headquartered in Norwood, MA.

The ADM706 family was designed specifically for robust microprocessor supervision in mission-critical embedded systems, emphasizing precision voltage monitoring, fail-safe reset assertion, and integrated watchdog functionality for automotive-qualified and industrial-grade applications.

FAQ

What is the reset threshold voltage of the ADM706SAN?

The ADM706SAN has a nominal reset threshold voltage of 2.93 V, with a guaranteed range of 2.85 V to 3.00 V over temperature and supply variations. This value is factory-trimmed and specified in Table 1 of the Rev. E datasheet. The ADM706SAN uses this threshold to assert its active-low RESET output whenever VCC falls below this level, ensuring reliable microprocessor supervision in 3 V systems. The 20 mV hysteresis prevents chatter during slow supply ramps.

Does the ADM706SAN include a watchdog timer?

Yes, the ADM706SAN includes a fully integrated watchdog timer with a nominal timeout period of 1.6 seconds. The timer resets on any transition (high-to-low or low-to-high) at the WDI pin and asserts the WDO output low if no transition occurs within that window. This function is confirmed in the Functional Block Diagram (Figure 1), General Description, and Specifications table. The ADM706SAN's watchdog operates independently of the reset generator and remains functional down to VCC = 1 V.

What package type is used for the ADM706SAN?

The ADM706SAN is packaged in an 8-lead narrow-body plastic dual in-line package (PDIP), designated N-8 per JEDEC MS-001. Its dimensions are 0.300 inches wide with 0.100 inch lead pitch, and it features tin-lead plating. This package is explicitly listed in the Ordering Guide under "ADM706SANZ" and confirmed in the Outline Dimensions section (Figure 24). The "AN" suffix in ADM706SAN denotes the PDIP variant.

Can the ADM706SAN monitor a second supply voltage?

Yes, the ADM706SAN can monitor a second supply using its dedicated PFI (Power-Fail Input) pin and PFO (Power-Fail Output) pin. The internal 1.25 V comparator allows external resistor dividers to scale higher voltages (e.g., 5 V, 12 V) down to the 1.25 V trip point. As shown in Figure 22 of the datasheet, PFO can be connected to MR to generate a reset when the auxiliary supply fails. This capability is intrinsic to the ADM706SAN's architecture and does not require additional components beyond the divider resistors.

Is the ADM706SAN pin-compatible with the MAX706S?

Yes, the ADM706SAN is a direct functional and pin-compatible replacement for the MAX706S in PDIP packages. Both devices share identical pinouts (MR, VCC, GND, PFI, PFO, WDI, RESET, WDO), matching reset threshold (2.93 V), reset pulse width (200 ms), watchdog timeout (1.6 s), and operating temperature range (−40°C to +85°C). Analog Devices explicitly positions the ADM706 series as a "superior upgrade for MAX706P/R/S/T" in the Features section, confirming drop-in compatibility for legacy designs.