Analog Devices Inc. ADA4084-4ACPZ-RL

Overview

ADA4084-4ACPZ-RL from Analog Devices is a quad-channel, rail-to-rail input/output, low-noise operational amplifier optimized for precision analog signal conditioning in single- or dual-supply systems. It delivers 15.9 MHz gain bandwidth, 4.6 V/µs slew rate, and 3.9 nV/√Hz voltage noise density at 1 kHz, operating from ±1.5 V to ±15 V (or +3 V to +30 V). It is used in high-side/low-side current sensing and ADC input buffering where dc accuracy and wide dynamic range are critical.

For engineers reviewing the ADA4084-4ACPZ-RL datasheet, ADA4084-4ACPZ-RL pinout, ADA4084-4ACPZ-RL application, or ADA4084-4ACPZ-RL equivalent, key selection criteria include its 16-lead LFCSP package with exposed pad tied to V−, guaranteed −40°C to +125°C operation, 100 µV max offset voltage (SOIC), and rail-to-rail swing enabling full-scale signal utilization in battery-powered instrumentation and power supply control loops.

Technical Context

The ADA4084-4ACPZ-RL implements a folded-cascode architecture with internal biasing optimized for low power (0.625 mA per amplifier at ±15 V) and low noise across its 15.9 MHz bandwidth. Its unity-gain stability and 86° phase margin support robust closed-loop performance without external compensation in gain-of-1 to gain-of-100 configurations.

Input stage design enables true rail-to-rail common-mode range (V− to V+) and output swing within 10 mV of rails under light load, while matched input transistors ensure 200 µV max offset voltage matching between channels in the LFCSP variant - critical for multichannel sensor front-ends and programmable gain amplifiers.

Key Specifications

Pinout & Package

The ADA4084-4ACPZ-RL is housed in a 16-lead LFCSP (CP-16-17) package with an exposed thermal pad that must be soldered to V− for optimal thermal performance and EMI suppression.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar quad precision op-amp applications.

Compared with ADA4084-4ACPZ-RL, ADA4004-4ARUZ trades 2.1 nV/√Hz higher noise for 2× better dc precision but doubles quiescent power, while OP4177ARUZ sacrifices 12× bandwidth to achieve 40% lower offset - making ADA4084-4ACPZ-RL the balanced choice for wideband precision in compact, high-temp industrial designs.

Availability

ADA4084-4ACPZ-RL is available at Aetrix Electronics and suitable for battery-powered instrumentation, high-side/low-side current sensing, and power supply control applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ADA4084-4ACPZ-RL 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, headquartered in Norwood, MA, with R&D and manufacturing facilities worldwide.

The ADA4084 family was designed specifically for precision, low-noise, rail-to-rail op-amp applications in industrial, instrumentation, and medical systems demanding wide supply range, high reliability, and guaranteed operation from −40°C to +125°C.

FAQ

What is the recommended power supply decoupling for ADA4084-4ACPZ-RL?

Each V+ and V− pin of the ADA4084-4ACPZ-RL requires a 100 nF X7R ceramic capacitor placed within 2 mm of the pin and connected to a solid ground plane. For high-frequency stability, add a 10 µF tantalum or aluminum polymer capacitor near the device. The exposed pad must be soldered to V− and connected to the ground plane via ≥4 thermal vias to maintain θ_JA ≤ 55°C/W and minimize supply-induced crosstalk between channels.

Does ADA4084-4ACPZ-RL support single-supply operation below 3 V?

No - the ADA4084-4ACPZ-RL is specified for operation from +3 V to +30 V (or ±1.5 V to ±15 V). Operation below +3 V violates absolute maximum ratings and results in undefined behavior, including loss of rail-to-rail input capability and degraded PSRR. For sub-3 V designs, consider the ADA4805-4 or AD8608 families, which are characterized down to +1.8 V.

How is the exposed pad of ADA4084-4ACPZ-RL electrically connected?

The exposed pad of the ADA4084-4ACPZ-RL is internally connected to the V− supply rail and must be externally soldered to the PCB's V− copper pour. It is not a ground terminal. Connecting it to GND instead of V− will cause functional failure and potential damage due to internal junction bias violations. Thermal vias beneath the pad must connect exclusively to the V− net.

Can ADA4084-4ACPZ-RL drive capacitive loads greater than 100 pF?

Yes - the ADA4084-4ACPZ-RL remains stable driving ≥500 pF loads when a 22 Ω isolation resistor is placed in series with the output. Without this resistor, oscillation may occur above ~100 pF. This configuration preserves 13.9 MHz −3 dB bandwidth and 4.6 V/µs slew rate while ensuring monotonic step response in DAC output buffering and piezoelectric actuator drive applications.

What is the maximum allowable differential input voltage for ADA4084-4ACPZ-RL?

The ADA4084-4ACPZ-RL has an absolute maximum differential input voltage rating of ±0.6 V. Exceeding this risks permanent damage to the input ESD protection diodes. If input signals may exceed this (e.g., during power sequencing or fault conditions), external 10 kΩ current-limiting resistors and clamp diodes to V+ and V− are required - as detailed in the "Input Protection" section of the Rev. I datasheet.