Analog Devices Inc. OP481GSZ

Overview

OP481GSZ from Analog Devices is a quad ultralow power rail-to-rail output operational amplifier designed for single-supply signal conditioning in battery-constrained systems. It delivers 4 μA/amplifier supply current, 1.5 mV max offset voltage, rail-to-rail output swing (within 25 mV of rails at 100 kΩ load), and operates from 2.7 V to 12 V - enabling use in safety monitoring, remote sensors, and low-voltage strain gage amplifiers.

For engineers reviewing the OP481GSZ datasheet, OP481GSZ pinout, OP481GSZ application, or OP481GSZ equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, application-specific implementation insights, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The OP481GSZ uses a precision bipolar input stage with PNP transistors enabling input common-mode range extending to ground - critical for single-supply operation. Its CMOS output stage achieves rail-to-rail swing while maintaining sub-4 μA quiescent current even when output is saturated at either rail.

It features no phase reversal under overvoltage conditions, fast saturation recovery (65–120 μs depending on supply), and stable operation into capacitive loads up to 10 nF without external compensation - enabled by 70–75° phase margin and optimized open-loop gain profile.

Key Specifications

Pinout & Package

OP481GSZ is packaged in a 14-lead narrow-body SOIC (R suffix) with exposed pad not present; thermal resistance θ_JA = 120°C/W. Pin functions are validated per Figure 3 of Rev. D datasheet.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultralow-power rail-to-rail op amp applications.

Compared with TLV2464IPW and MAX4470ASA+, OP481GSZ uniquely balances sub-4 μA consumption, guaranteed rail-to-rail output, no phase reversal, and −40°C to +85°C qualification - making it the only choice for ruggedized, long-life, single-supply instrumentation where signal integrity at supply extremes is mandatory.

Availability

OP481GSZ is available at Aetrix Electronics and suitable for remote sensor nodes, battery-powered safety monitors, and low-voltage strain gage amplifiers requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for OP481GSZ 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 precision instrumentation, industrial automation, and medical markets since 1965.

The OPx81 family - including OP481GSZ - was engineered specifically for micropower, single-supply sensor signal conditioning in battery-operated safety and monitoring systems where reliability at supply rail extremes is non-negotiable.

FAQ

What is the maximum supply voltage rating for OP481GSZ?

The absolute maximum supply voltage for OP481GSZ is 16 V, as specified in Table 4 of the Rev. D datasheet. However, functional operation is guaranteed only from 2.7 V to 12 V. Exceeding 12 V risks parametric degradation or latch-up, especially under temperature stress. For designs targeting 12 V operation, ensure PCB layout minimizes transient overshoot, and verify long-term reliability with accelerated life testing using OP481GSZ samples.

Does OP481GSZ support true rail-to-rail input common-mode range?

OP481GSZ does not support rail-to-rail input common-mode range. Its specified input common-mode voltage range extends from V− to (V+ − 1 V). However, the bipolar PNP input stage allows operation with inputs slightly below V− (e.g., −0.2 V at V− = GND), as demonstrated in Figure 37. This partial extension enables limited negative signal handling in single-supply configurations, but intentional operation below V− requires series input current limiting per the datasheet's Input Overvoltage Protection section to avoid phase reversal.

Can OP481GSZ be used as a comparator, and what are its propagation delay characteristics?

Yes, OP481GSZ is explicitly characterized for comparator use due to its fast saturation recovery time (65 μs at 3 V, 120 μs at ±5 V) and no phase reversal behavior. Propagation delay is not specified as a comparator parameter in the datasheet; instead, saturation recovery time governs response after overdrive. For window comparator applications like those in Figure 41, OP481GSZ delivers reliable decision timing within 120 μs, making it suitable for slow-changing process variables (e.g., temperature, pressure) but not for kHz-frequency signal edge detection.

What is the thermal performance of OP481GSZ in its 14-lead SOIC package?

In the 14-lead narrow-body SOIC (R suffix) package, OP481GSZ has a junction-to-ambient thermal resistance (θ_JA) of 120°C/W and junction-to-case (θ_JC) of 36°C/W, per Table 5 of Rev. D. Under worst-case 12 V operation with all four amplifiers active at 4 μA each (total 16 μA), power dissipation is ~192 μW - resulting in negligible self-heating (<0.025°C rise). This confirms thermal derating is unnecessary in standard PCB layouts, and the device remains within specifications even in sealed enclosures at +85°C ambient.

How does OP481GSZ handle capacitive loads, and what is the maximum stable capacitance?

OP481GSZ is designed to drive moderate capacitive loads without external compensation, thanks to its 70–75° phase margin. Figure 39 shows stable step response with 10 nF at the output and 3 V supply, exhibiting <10% overshoot. While the datasheet does not specify a hard maximum, empirical data confirms stability up to 10 nF under typical conditions. For loads >10 nF or demanding settling-time requirements, a small series resistor (e.g., 10–50 Ω) between OP481GSZ output and the capacitor is recommended to isolate the reactive load and preserve phase margin.