Analog Devices Inc. ADM709MAR

Overview

ADM709MAR 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 timeout, and operation down to 1 V supply voltage. It serves as a system supervisory device in microprocessor-based systems requiring reliable brownout and power-up reset signaling.

For engineers reviewing the ADM709MAR datasheet, ADM709MAR pinout, ADM709MAR application, or ADM709MAR equivalent, key selection considerations include reset threshold accuracy (±0.15 V), guaranteed RESET assertion at VCC ≥ 1 V, SO-8 package compatibility, and quiescent current under 110 µA across –40°C to +85°C.

Technical Context

The ADM709MAR 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. Its RESET output remains asserted during brownout and power-down until VCC drops below 4.25 V (min) and sustains valid logic low down to 1 V supply.

It features glitch immunity on VCC via internal filtering and supports bidirectional µP reset lines using external series resistors. No external capacitor is required for basic operation, though 0.1 µF local decoupling improves transient immunity.

Key Specifications

Pinout & Package

ADM709MAR is housed in an 8-lead SOIC (SO-8) package with 1.27 mm pitch. Pin 1 is marked by a beveled corner or dot; pins 1, 4, 5, 6, and 8 are no-connect terminals.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX709RCSA+ and TPS3808G33DBVR, the ADM709MAR provides exact 4.40 V monitoring with proven industrial temperature stability and SO-8 drop-in compatibility-ideal for upgrading legacy ADM709L/M-based systems without layout changes.

Availability

ADM709MAR is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, medical handheld diagnostics, and network edge routers requiring stable component supply and long-term lifecycle support.

Supply support for ADM709MAR 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, founded in 1965 and headquartered in Wilmington, MA.

The ADM709 belongs to Analog Devices' supervisory IC product line, designed specifically for robust, low-power power-on and brownout reset generation in microprocessor-based systems operating across extended industrial temperatures.

FAQ

What is the exact reset threshold voltage for ADM709MAR?

The ADM709MAR has a nominal reset threshold of 4.40 V, with a guaranteed range of 4.25 V (min) to 4.50 V (max) over the full –40°C to +85°C temperature range. This value is laser-trimmed at wafer test and specified in the Absolute Maximum Ratings table of the official ADM709 datasheet Rev. 0.

Does ADM709MAR support operation below 2.0 V VCC?

Yes, ADM709MAR guarantees functional RESET output down to VCC = 1.0 V. Below 1 V, the RESET output may become indeterminate; a 100 kΩ pull-down resistor to GND is recommended if sustained low-state assertion is required below 1 V, as documented in Figure 5 of the ADM709 datasheet.

Is ADM709MAR pin-compatible with other ADM709 variants?

Yes, all ADM709 variants-including ADM709MAR, ADM709LAN, and ADM709TAR-share identical SO-8 or N-8 pinouts and terminal functions. Only the reset threshold voltage differs between suffixes; no PCB layout change is needed when substituting within the same package type.

What is the maximum sink current capability of the ADM709MAR RESET pin?

The ADM709MAR RESET output can sink up to 3.2 mA while maintaining VOL ≤ 0.4 V, tested at VCC ≥ reset threshold minimum (4.25 V). This drive strength supports direct interfacing with standard TTL and CMOS microprocessor reset inputs without external buffering.

Can ADM709MAR replace MAX709 in existing designs?

Yes, ADM709MAR is a functional upgrade for MAX709 in SO-8 configurations, offering tighter threshold accuracy (±0.15 V vs. ±2.5%), lower quiescent current (35 µA vs. ~50 µA), and improved brownout response down to 1 V. Layout and firmware require no modification for drop-in replacement.