Analog Devices Inc. ADM708SARZ

Overview

ADM708SARZ from Analog Devices is a 3 V microprocessor supervisory circuit with active-high and active-low reset outputs, 2.93 V reset threshold, 200 ms reset pulse width, and power-fail monitoring via 1.25 V PFI comparator - used in battery-operated instruments and industrial controllers to ensure reliable power-on and brownout reset behavior.

For engineers reviewing the ADM708SARZ datasheet, ADM708SARZ pinout, ADM708SARZ application, or ADM708SARZ equivalent, key selection considerations include dual-reset polarity support, guaranteed RESET validity down to 1 V VCC, absence of watchdog timer (distinguishing it from ADM706S), and SOIC-8 packaging for space-constrained embedded designs.

Technical Context

The ADM708SARZ implements a precision voltage monitor with fixed 2.93 V reset threshold and hysteresis of 20 mV, ensuring stable reset assertion/deassertion during supply ramp-up and brownout recovery. Its dual-reset architecture provides both RESET (active low) and RESET (active high) outputs simultaneously, eliminating need for external inverters in bidirectional or mixed-logic systems.

It integrates a dedicated 1.25 V reference-based power-fail comparator (PFI/PFO), enabling early warning of supply collapse or low-battery conditions without external components. Unlike the ADM706S family, it omits watchdog timer circuitry - simplifying timing-critical applications where software-driven supervision is unnecessary or handled elsewhere.

Key Specifications

Pinout & Package

ADM708SARZ is housed in an 8-lead narrow SOIC package (R-8), measuring 5.00 mm × 4.00 mm × 1.25 mm, with gull-wing leads and JEDEC MS-012-AA compliance. Pin 1 is marked by a beveled corner or dot; device orientation follows standard SOIC top-view convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADM706SARZ, ADM708SARZ trades watchdog capability for dual-reset simplicity and lower current draw; compared with MAX708SUR+, it offers tighter reset threshold accuracy (±40 mV vs ±100 mV) and superior sub-1 V reset validity - making it preferable for precision battery monitoring and low-power industrial control.

Availability

ADM708SARZ is available at Aetrix Electronics and suitable for battery-operated instruments, industrial PLC modules, and medical point-of-care devices requiring stable component supply with guaranteed long-term availability and traceable sourcing.

Supply support for ADM708SARZ 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 ADM708SARZ belongs to Analog Devices' microprocessor supervisory product line, engineered specifically for robust power monitoring in resource-constrained embedded systems where reliability, low power, and dual-reset flexibility are mandatory.

FAQ

What is the reset threshold voltage of the ADM708SARZ?

The ADM708SARZ has a nominal reset threshold of 2.93 V, with a tolerance of ±40 mV (2.85 V to 3.00 V). This value is factory-trimmed and specified over the full industrial temperature range (−40°C to +85°C). The threshold applies to both RESET and RESET outputs and remains stable across VCC variations from 1.0 V to 5.5 V. This precise 2.93 V setting makes ADM708SARZ ideal for supervising 3 V systems where margin above typical LDO dropout is critical.

Does the ADM708SARZ include a watchdog timer?

No, the ADM708SARZ does not include a watchdog timer. It is functionally identical to the ADM706S series except for the omission of the WDI and WDO pins and associated timing circuitry. The ADM708SARZ retains all core supervision features - dual-reset outputs, PFI/PFO comparator, MR debouncing, and 200 ms reset pulse - but is optimized for applications where software-level watchdog supervision is handled externally or not required. For watchdog capability, consider ADM706SARZ instead.

How does the ADM708SARZ handle power-fail detection?

The ADM708SARZ uses an internal 1.25 V reference to compare against an external voltage applied to the PFI pin. When PFI falls below 1.25 V, the PFO output goes low, signaling impending power failure. This allows designers to configure early-warning thresholds using a simple resistor divider on any auxiliary rail (e.g., 5 V, 12 V, or battery). PFO is an active-low open-drain output requiring an external pull-up; it can directly drive MCU interrupts or be tied to MR for automatic system reset on power collapse.

Can the ADM708SARZ operate with VCC below 2.7 V?

Yes, the ADM708SARZ is fully specified to operate with VCC as low as 1.0 V. Its RESET and RESET outputs remain valid and functional down to this level, ensuring the microprocessor stays held in reset during deep brownout or battery depletion. This capability is verified across temperature and process corners and is a key differentiator versus many competing supervisors that cease operation below 2.0 V. The 1 V minimum also enables use with partially discharged lithium batteries or energy-harvesting sources.

What package options are available for the ADM708SARZ?

The ADM708SARZ is available exclusively in the 8-lead narrow SOIC package (R-8), per the ordering guide. It is not offered in PDIP or other variants. The R-8 package measures 5.00 mm × 4.00 mm × 1.25 mm, features 1.27 mm lead pitch, and complies with JEDEC MS-012-AA standards. This surface-mount package supports automated assembly, offers good thermal performance (θJA = 110°C/W), and is widely supported by PCB design libraries and pick-and-place equipment.