AD8618ARZ - 20MHz CMOS Quad Rail-to-Rail Op Amp | Analog Devices
MPN: AD8618ARZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.35 | $4.35 |
| 10 | $3.92 | $39.20 |
| 100 | $3.49 | $349.00 |
| 500 | $3.14 | $1,570.00 |
| 1,000 | $2.83 | $2,830.00 |
AD8618ARZ Overview
An operational amplifier (op amp) is a high-gain voltage amplifier with differential inputs and a single-ended output. It is a fundamental building block in analog signal conditioning, used to amplify, filter, or buffer signals. The AD8618 belongs to the precision CMOS op amp family, which combines low power consumption with high accuracy, making it suitable for battery-powered and high-resolution systems.
Key features include a maximum offset voltage of 65 µV, a gain-bandwidth product of 20 MHz, a slew rate of 12 V/µs, and a low noise density of 8 nV/√Hz. The rail-to-rail input and output stages allow the amplifier to operate with the full supply range, maximizing dynamic range in single-supply applications. The device also features a patented trimming technique that ensures low offset and drift over temperature.
The AD8618 uses a CMOS process technology, which provides high input impedance and low input bias current, typically in the picoampere range. This makes it suitable for interfacing with high-impedance sensors and precision integrators. The quad configuration allows for compact designs, reducing board space and component count in multi-channel systems.
Typical applications include portable instrumentation, active filters, analog-to-digital converter (ADC) drivers, and audio signal conditioning. The low noise and wide bandwidth make it suitable for medical and industrial sensing applications where signal integrity is critical.
When designing with the AD8618, ensure proper power supply decoupling with 0.1 µF ceramic capacitors close to the supply pins. The rail-to-rail output stage can drive capacitive loads, but a series resistor may be needed to maintain stability with large load capacitances.
Drop-in alternatives for AD8618ARZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with AD8618ARZ (same form factor and footprint) — differing in Gain Bandwidth Product, Package, Supply Voltage Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD8608ARZ
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →AD8618ARZ Maximum Ratings & Electrical Characteristics
| Number of Channels | 4 |
| Supply Voltage Range | 2.7 V to 5 V |
| Gain Bandwidth Product | 20 MHz |
| Slew Rate | 12 V/µs |
| Offset Voltage (max) | 65 µV |
| Input Voltage Noise Density | 8 nV/√Hz |
| Input Bias Current | 0.2 pA (typ) |
| Rail-to-Rail Input | Yes |
| Rail-to-Rail Output | Yes |
| Operating Temperature Range | -40°C to +125°C |
| Package | 14-SOIC |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Amplifier Type | CMOS |
AD8618ARZ Pin Configuration
| Pin 1 | OUT A — Output of amplifier A |
| Pin 2 | -IN A — Inverting input of amplifier A |
| Pin 3 | +IN A — Non-inverting input of amplifier A |
| Pin 4 | V+ — Positive supply |
| Pin 5 | +IN B — Non-inverting input of amplifier B |
| Pin 6 | -IN B — Inverting input of amplifier B |
| Pin 7 | OUT B — Output of amplifier B |
| Pin 8 | OUT C — Output of amplifier C |
| Pin 9 | -IN C — Inverting input of amplifier C |
| Pin 10 | +IN C — Non-inverting input of amplifier C |
| Pin 11 | V- — Negative supply (ground in single-supply) |
| Pin 12 | +IN D — Non-inverting input of amplifier D |
| Pin 13 | -IN D — Inverting input of amplifier D |
| Pin 14 | OUT D — Output of amplifier D |
Typical Applications
AD8618ARZ is suitable for 6 applications: Portable Instrumentation, Active Filters, ADC Driver, Audio Signal Conditioning, Medical Sensing, Industrial Control.
Portable Instrumentation
The AD8618ARZ's low power consumption and rail-to-rail operation make it ideal for battery-powered instruments. Its 2.7V to 5V supply range aligns with Li-ion battery outputs, and the low offset voltage (65 µV max) ensures accurate measurements. The quad configuration allows multiple signal conditioning channels in a compact footprint, reducing board space and extending battery life in handheld multimeters and data loggers.
Recommended
Active Filters
With a 20 MHz gain bandwidth product and 12 V/µs slew rate, the AD8618ARZ is well-suited for active filter designs in communication and audio systems. The high bandwidth allows implementation of Butterworth or Chebyshev filters up to several megahertz. The low noise (8 nV/√Hz) preserves signal-to-noise ratio, and the rail-to-rail output maximizes dynamic range. Each of the four amplifiers can be used for a different filter stage, enabling compact multi-pole designs.
Recommended
ADC Driver
The AD8618ARZ can drive high-resolution ADCs with its low output impedance and rail-to-rail output. Its 20 MHz bandwidth ensures minimal settling time for fast sampling rates, and the low noise (8 nV/√Hz) does not degrade the ADC's SNR. The quad configuration allows buffering multiple ADC inputs, such as in a data acquisition system. The device's low offset voltage (65 µV) minimizes DC errors in the signal chain.
Recommended
Audio Signal Conditioning
The AD8618ARZ's low noise (8 nV/√Hz) and wide bandwidth (20 MHz) make it suitable for audio preamplifiers and equalizers. The rail-to-rail output allows maximum signal swing without clipping, and the low distortion ensures high-fidelity reproduction. The quad configuration enables stereo channels with additional filtering or mixing stages. Its single-supply operation simplifies audio system design, and the low power consumption is beneficial for portable audio devices.
Recommended
Medical Sensing
In medical devices like ECG and pulse oximeters, the AD8618ARZ provides low-noise amplification of biosignals. Its low input bias current (0.2 pA) minimizes loading on high-impedance electrodes, and the low offset voltage (65 µV) reduces baseline drift. The 2.7V to 5V supply range is compatible with battery-powered medical monitors. The quad configuration allows multiple signal channels for multi-lead ECG, and the wide bandwidth supports fast signal transients.
Recommended
Industrial Control
The AD8618ARZ is used in industrial control systems for signal conditioning of sensors and actuators. Its wide supply range (2.7V to 5V) and rail-to-rail operation interface directly with microcontrollers and ADCs. The low offset voltage ensures accurate process control, and the 20 MHz bandwidth supports fast control loops. The quad configuration reduces component count in multi-channel PLCs and motor controllers, and the -40°C to +125°C temperature range suits harsh environments.
Recommended
Recommended Products Summary
Engineering reference data for AD8618ARZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD8608ARZ | AD8618ARUZ | OPA4227PA |
|---|---|---|---|---|
| Package | 14-SOIC | 14-SOIC | 14-TSSOP | 14-DIP |
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments |
| Number of Channels | 4 | 4 | 4 | 4 |
| Gain Bandwidth Product | 20 MHz | 10 MHz | 20 MHz | 8 MHz |
| Slew Rate | 12 V/µs | 5 V/µs | 12 V/µs | 2.3 V/µs |
| Offset Voltage (max) | 65 µV | 65 µV | 65 µV | 75 µV |
| Input Noise Density | 8 nV/√Hz | 12 nV/√Hz | 8 nV/√Hz | 4.5 nV/√Hz |
| Supply Voltage Range | 2.7V to 5V | 2.7V to 5V | 2.7V to 5V | ±2.5V to ±18V |
Key Differentiators
- Higher bandwidth than AD8608ARZ (vs AD8608ARZ)
- Lower noise than AD8608ARZ (vs AD8608ARZ)
- Lower offset voltage than OPA4227 (vs OPA4227PA)
Design Notes
The AD8618ARZ operates from a single 2.7V to 5V supply. Use a 0.1 µF ceramic capacitor close to each supply pin (V+ and V-) to decouple high-frequency noise. For optimal performance, a 10 µF tantalum capacitor in parallel is recommended for low-frequency stability. Ensure the supply voltage does not exceed 5V to avoid damage.
For best noise performance, keep the input traces short and shielded from digital signals. Use a ground plane under the op amp to reduce parasitic capacitance and noise pickup. Place the feedback resistors close to the inverting input to minimize stray capacitance, which can cause instability. The 14-SOIC package has a 1.27 mm pitch, allowing standard PCB routing.
The rail-to-rail output stage can drive capacitive loads, but large capacitances ( >100 pF) may cause oscillation. Add a series resistor (e.g., 50Ω) at the output to isolate capacitive loads. Also, avoid exceeding the input common-mode range, even though it extends beyond the rails; doing so may cause phase reversal. Always refer to the datasheet's absolute maximum ratings.
Compliance Information
RoHS compliant per Analog Devices product page. Not AEC-Q100 qualified.
