AD8605ARZ - Precision CMOS Rail-to-Rail Op Amp | Analog Devices
MPN: AD8605ARZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.5 | $2.50 |
| 10 | $2.25 | $22.50 |
| 100 | $1.95 | $195.00 |
| 500 | $1.75 | $875.00 |
| 1,000 | $1.6 | $1,600.00 |
Drop-in alternatives for AD8605ARZ — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
AD8606ARZ
✅ Drop-In✓ In Stock
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View Datasheet →OPA376AIDR
✅ Drop-In📋 Reference alternative (not in catalog)
MCP6V11-E/SN
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AD8605ARZ-REEL
✅ Drop-In📋 Reference alternative (not in catalog)
AD8605ARZ Maximum Ratings & Electrical Characteristics
| Number of Channels | 1 |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Input Offset Voltage (max) | 65 µV |
| Input Bias Current (max) | 1 pA |
| Gain-Bandwidth Product | 10 MHz |
| Slew Rate | 5 V/µs |
| Voltage Noise Density | 7 nV/√Hz |
| Current Noise Density | 0.01 pA/√Hz |
| Rail-to-Rail Input | Yes |
| Rail-to-Rail Output | Yes |
| Operating Temperature Range | -40°C to +125°C |
| Package | SOIC-8 (R-8) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Amplifier Type | Precision CMOS |
AD8605ARZ Pin Configuration
| Pin 1 | OUT — Output |
| Pin 2 | -IN — Inverting input |
| Pin 3 | +IN — Non-inverting input |
| Pin 4 | V- — Negative supply |
| Pin 5 | V+ — Positive supply |
| Pin 6 | OUT — Output (duplicate for single version, often NC) |
| Pin 7 | NC — No connect |
| Pin 8 | V+ — Positive supply (duplicate) |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
AD8605ARZ is suitable for 6 applications: Photodiode Amplifier, Portable Medical Devices, Audio Signal Conditioning, Active Filters, Sensor Interface, Data Acquisition Systems.
Photodiode Amplifier
The AD8605ARZ's ultra-low input bias current (1 pA) and low noise (7 nV/√Hz) make it ideal for transimpedance amplifiers in optical sensing systems. The wide bandwidth (10 MHz) supports fast optical signals, while the rail-to-rail output maximizes dynamic range. In a typical photodiode circuit, the op amp converts the photocurrent to a voltage with high precision, and the low bias current minimizes dark current errors. The CMOS input stage ensures negligible loading on the photodiode, preserving signal integrity. This configuration is widely used in medical diagnostics, industrial sensors, and communication receivers.
Recommended
Portable Medical Devices
The AD8605ARZ operates from a 2.7 V to 5.5 V supply, making it suitable for battery-powered medical devices such as glucose monitors and pulse oximeters. Its low power consumption and high precision ensure accurate signal conditioning for biosensors. The rail-to-rail input and output allow full-scale signal processing with a single supply, simplifying design. The small SOIC-8 package is compact enough for portable devices, and the wide temperature range (-40°C to +125°C) ensures reliability in clinical environments. The low offset voltage (65 µV) and low noise contribute to precise measurement of weak biological signals.
Recommended
Audio Signal Conditioning
The AD8605ARZ's low noise (7 nV/√Hz) and low distortion make it an excellent choice for audio preamplifiers and active filters. The wide bandwidth (10 MHz) preserves audio fidelity, while the rail-to-rail output maximizes headroom in single-supply audio systems. In a typical audio chain, the op amp buffers or amplifies signals from microphones or line-level sources. The low input bias current prevents DC offset errors, and the high slew rate (5 V/µs) ensures accurate reproduction of fast transients. This makes the AD8605ARZ suitable for portable audio devices, mixing consoles, and professional audio equipment.
Recommended
Active Filters
The AD8605ARZ's high gain-bandwidth product (10 MHz) and low noise make it ideal for active filter designs, such as low-pass, high-pass, and band-pass filters. The rail-to-rail input and output allow the filter to process signals close to the supply rails, maximizing dynamic range. In a Sallen-Key or multiple-feedback topology, the op amp provides the necessary gain and frequency response. The low offset voltage ensures accurate DC performance, and the low input bias current minimizes errors in high-impedance filter networks. This makes the AD8605ARZ suitable for data acquisition systems, communication equipment, and instrumentation.
Recommended
Sensor Interface
The AD8605ARZ is ideal for interfacing with high-impedance sensors such as pH probes, thermocouples, and strain gauges. Its ultra-low input bias current (1 pA) minimizes loading on the sensor, preserving measurement accuracy. The low offset voltage (65 µV) and low noise (7 nV/√Hz) ensure precise signal conditioning. The rail-to-rail input allows the amplifier to handle signals that span the entire supply range, which is common in sensor outputs. The wide bandwidth supports dynamic sensor signals, and the small package is suitable for compact sensor modules. This makes the AD8605ARZ a versatile choice for industrial and scientific instrumentation.
Recommended
Data Acquisition Systems
The AD8605ARZ's precision and low noise make it suitable for data acquisition systems, where it can buffer or amplify analog signals before ADC conversion. The rail-to-rail output ensures the full-scale range of the ADC is utilized, and the low offset voltage minimizes conversion errors. The wide bandwidth (10 MHz) supports high-speed sampling, while the low input bias current prevents errors from source impedance. In a typical DAQ system, the op amp conditions signals from sensors or transducers, providing the necessary gain and filtering. The small SOIC-8 package allows for dense board layouts, and the wide temperature range ensures reliable operation in industrial environments.
Recommended
Recommended Products Summary
Engineering reference data for AD8605ARZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | AD8605ARTZ-REEL | AD8606ARZ | OPA376AIDR | MCP6V11-E/SN |
|---|---|---|---|---|---|
| Package | SOIC-8 | SOT-23-5 | SOIC-8 | SOIC-8 | SOIC-8 |
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Microchip Technology |
| Number of Channels | 1 | 1 | 2 | 1 | 1 |
| Supply Voltage Range | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.7 V to 5.5 V | 2.2 V to 5.5 V | 2.2 V to 5.5 V |
| Input Offset Voltage (max) | 65 µV | 65 µV | 65 µV | 25 µV | 2 µV |
| Input Bias Current (max) | 1 pA | 1 pA | 1 pA | 0.2 pA | 50 pA |
| Gain-Bandwidth Product | 10 MHz | 10 MHz | 10 MHz | 5.5 MHz | 2 MHz |
| Voltage Noise Density | 7 nV/√Hz | 7 nV/√Hz | 7 nV/√Hz | 7.5 nV/√Hz | 0.25 µVpp (0.1-10 Hz) |
Key Differentiators
- Higher gain-bandwidth product (10 MHz) compared to OPA376AIDR (5.5 MHz) (vs OPA376AIDR)
- Lower input bias current (1 pA) compared to MCP6V11-E/SN (50 pA) (vs MCP6V11-E/SN)
- Same package and pinout as AD8606ARZ (dual version) (vs AD8606ARZ)
Design Notes
The AD8605ARZ operates from a single supply of 2.7 V to 5.5 V. Use a 0.1 µF ceramic capacitor close to the V+ pin and a 10 µF tantalum capacitor for bulk decoupling. For dual-supply operation, connect V- to the negative rail and add similar decoupling. Proper decoupling prevents oscillation and reduces noise coupling from the power supply.
For optimal performance, place the AD8605ARZ close to the signal source to minimize trace length and parasitic capacitance. Use a ground plane to reduce noise and provide a low-impedance return path. Keep feedback resistors and capacitors close to the inverting input to minimize stray capacitance, which can cause instability. For high-impedance sources, guard traces around the inputs to reduce leakage currents.
Avoid exceeding the absolute maximum supply voltage of 6 V, as this can damage the device. Ensure the input voltages do not exceed the supply rails by more than 0.3 V, even though the input is rail-to-rail. The output can swing close to the rails but cannot drive loads that require current beyond the specified output current (typically ±30 mA). For capacitive loads, add a series resistor to prevent oscillation.
Compliance Information
RoHS compliant per Analog Devices product page. No AEC-Q100 qualification indicated for this part.
