Analog Devices Inc. ADM709MARZ

Overview

ADM709MARZ from Analog Devices is a precision power supply monitor IC with active-low reset output, 4.40 V threshold, 140 ms minimum power-on reset pulse, and operation down to 1 V supply voltage; used for reliable microprocessor reset in industrial embedded systems during power-up, brownout, and power-down events.

For engineers reviewing the ADM709MARZ datasheet, ADM709MARZ pinout, ADM709MARZ application, or ADM709MARZ equivalent, key selection criteria include reset threshold accuracy, guaranteed RESET hold time at low VCC, quiescent current under temperature extremes, and SOIC-8 compatibility with legacy MAX709-based designs.

Technical Context

The ADM709MARZ implements a bandgap-based voltage comparator with internal timing circuitry to generate a minimum 140 ms active-low RESET pulse after VCC rises above 4.40 V (±50 mV), holding RESET low until VCC drops below 4.25 V (min) or rises above 4.50 V (max). It operates across –40°C to +85°C with no external components required.

RESET remains functional down to VCC = 1.0 V, enabling stable shutdown signaling even during deep undervoltage conditions; glitch immunity is achieved via internal filtering, eliminating need for external RC networks on VCC in most applications.

Key Specifications

Pinout & Package

ADM709MARZ is housed in an 8-lead SOIC (SO-8) package with standard 1.27 mm pitch, 5.0 mm × 6.2 mm footprint, and gull-wing leads compatible with automated PCB assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power supply monitor applications.

Compared with MAX709SUR+ and TPS3808G33DBVR, the ADM709MARZ uniquely combines 4.40 V precision threshold, 1 V operational floor, and fixed 140 ms timeout in SO-8-making it optimal for legacy +5 V industrial designs requiring brownout resilience without layout changes.

Availability

ADM709MARZ is available at Aetrix Electronics and suitable for industrial PLC controllers, embedded data acquisition systems, and automotive body control modules requiring stable component supply with guaranteed long-term availability.

Supply support for ADM709MARZ 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, headquartered in Norwood, MA.

The ADM709 belongs to Analog Devices' precision power monitoring product line, designed specifically for deterministic microprocessor reset generation in industrial, automotive, and medical systems where supply stability is mission-critical.

FAQ

What is the exact reset threshold voltage for ADM709MARZ?

The ADM709MARZ has a nominal reset threshold of 4.40 V, with guaranteed limits of 4.25 V (minimum) and 4.50 V (maximum) across the full –40°C to +85°C temperature range. This value is laser-trimmed at wafer test and does not require external calibration. The ADM709MARZ threshold is optimized for monitoring +5 V and +3.3 V power rails in industrial microprocessor systems.

Does ADM709MARZ support operation below 1.8 V VCC?

Yes, the ADM709MARZ guarantees functional RESET output down to VCC = 1.0 V, enabling reliable reset assertion during deep brownout conditions where other supervisors cut off. Below 1.0 V, a 100 kΩ pull-down resistor on the RESET pin is recommended to maintain low state. This capability is explicitly specified in the ADM709MARZ datasheet and distinguishes it from many competing supervisors.

Is ADM709MARZ pin-compatible with MAX709 series devices?

Yes, ADM709MARZ uses the same SO-8 package and identical pinout as MAX709M variants (e.g., MAX709MCSA+), including VCC on Pin 2, GND on Pin 3, and active-low RESET on Pin 7. All NC pins (1, 4, 5, 6, 8) align exactly. No PCB layout change is needed for drop-in replacement, though designers should verify timing and threshold alignment for their specific use case.

What is the typical supply current of ADM709MARZ at 3.3 V and 25°C?

At VCC = 3.3 V and TA = 25°C, the ADM709MARZ draws 35 µA typical supply current, with a maximum of 110 µA over the full –40°C to +85°C range. This ultra-low quiescent current makes the ADM709MARZ suitable for always-on monitoring in battery-powered or energy-harvesting applications where standby power budget is critical.

Can ADM709MARZ drive a microprocessor reset input directly?

Yes, the ADM709MARZ RESET pin is an active-low open-drain output capable of sinking 3.2 mA at its specified threshold voltage, sufficient to drive standard TTL/CMOS microprocessor reset inputs. An external pull-up resistor (typically 10 kΩ to VCC) is required. For bidirectional microprocessor reset lines (e.g., MC68HC11), a 4.7 kΩ series resistor is recommended to prevent contention, as documented in the ADM709MARZ application circuit guidelines.