Analog Devices Inc. ADM1185ARMZ-1REEL7

Overview

ADM1185ARMZ-1REEL7 from Analog Devices is a quad-voltage monitor and sequencer IC designed for precise power-rail supervision in multi-rail systems. It features four 0.6 V reference comparators with ±0.8% threshold accuracy, 100–280 ms programmable sequencing delays, three open-drain enable outputs (OUT1–OUT3), and one open-drain power-good output (PWRGD), operating from 2.7 V to 5.5 V on VCC. It is used in server motherboard power sequencing to ensure safe startup of 3.3 V, 2.5 V, 1.8 V, and 1.2 V rails.

For engineers reviewing the ADM1185ARMZ-1REEL7 datasheet, ADM1185ARMZ-1REEL7 pinout, ADM1185ARMZ-1REEL7 application, or ADM1185ARMZ-1REEL7 equivalent, this page delivers verified specifications, functional context, package details, real-world use cases, and validated alternative options - all grounded in the official Rev. B datasheet and Analog Devices' product documentation.

Technical Context

The ADM1185ARMZ-1REEL7 implements a deterministic state-machine core that interprets comparator outputs to enforce a five-state power-up sequence: Reset → OUT1 On → OUT1/OUT2 On → OUT1/OUT2/OUT3 On → Power Good. Each transition requires sustained valid input voltage (e.g., VIN1 ≥ 0.6 V for 190 ms typical) before advancing.

After reaching the Power Good (STATE5) state, the device enters fault-monitoring mode: a drop below 0.6 V on VIN1 disables all outputs and deasserts PWRGD; drops on VIN2–VIN4 deassert PWRGD only while maintaining OUT1–OUT3 active. All inputs accept externally scaled rail voltages via resistor dividers, and all outputs are open-drain with guaranteed low-voltage performance down to 0.4 V at 2 mA sink current.

Key Specifications

Pinout & Package

ADM1185ARMZ-1REEL7 is housed in a 10-lead MSOP (RM-10) package per JEDEC MO-187-BA, with 0.5 mm pitch, 3.0 mm × 3.0 mm body, and 1.10 mm max height. Thermal resistance θ_JA = 137.5°C/W.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad-voltage monitoring and sequencing applications.

Compared with TPS3808G33DBVR and MAX6816EUB+, the ADM1185ARMZ-1REEL7 uniquely integrates a five-state sequencer, 0.8% threshold precision, and coordinated open-drain outputs - eliminating external timing elements and reducing PCB footprint by >60% versus discrete solutions.

Availability

ADM1185ARMZ-1REEL7 is available at Aetrix Electronics and suitable for server motherboard design, telecom equipment manufacturing, and industrial PLC development requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ADM1185ARMZ-1REEL7 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, with design centers worldwide.

The ADM1185ARMZ-1REEL7 belongs to Analog Devices' power supervision and sequencing product line, engineered specifically for reliable, deterministic power-up control in multi-rail computing and communications infrastructure.

FAQ

What is the minimum VCC voltage required for ADM1185ARMZ-1REEL7 to assert any output?

The ADM1185ARMZ-1REEL7 begins asserting outputs (pulling them low) once VCC reaches 1 V, though full specified operation - including accurate threshold detection and sequencing delays - requires VCC ≥2.7 V. At 1 V, OUT1–OUT3 and PWRGD are driven low, providing a basic enable-block function before full power-up.

Can ADM1185ARMZ-1REEL7 monitor a 5 V rail directly?

No - ADM1185ARMZ-1REEL7's comparators have a fixed 0.6 V reference. To monitor a 5 V rail, a resistor divider must scale the input so that 5 V maps to 0.6 V at the VINx pin (e.g., R1 = 73.3 kΩ, R2 = 10 kΩ). The datasheet confirms this method is standard practice and maintains 0.8% accuracy across temperature.

Does ADM1185ARMZ-1REEL7 support cascading with other ADM1185ARMZ-1REEL7 devices?

Yes - the ADM1185ARMZ-1REEL7 supports cascading via its open-drain outputs and inputs. For example, PWRGD from one device can drive VIN1 of a second, extending sequencing to >4 rails. Figures 23 and 24 in the Rev. B datasheet show two validated topologies for multi-device coordination without additional logic.

What happens to OUT1–OUT3 if VIN2 falls below threshold after PWRGD is asserted?

Nothing - once in STATE5 (PWRGD state), only a fault on VIN1 causes immediate deassertion of OUT1–OUT3. Faults on VIN2, VIN3, or VIN4 deassert PWRGD but leave OUT1–OUT3 unchanged, preserving local power to downstream circuits while signaling system-level fault to the host controller.

Is ADM1185ARMZ-1REEL7 pin-compatible with earlier revisions like ADM1185ARMZ-11?

Yes - ADM1185ARMZ-1REEL7 and ADM1185ARMZ-11 share identical 10-lead MSOP (RM-10) packaging, pinout, and electrical specifications per the Ordering Guide. Both operate over −40°C to +85°C and use the same M9W branding; the "REEL7" suffix denotes tape-and-reel packaging for automated assembly.