ADA4622-1ARJZ - 30V 8MHz Low Bias JFET Op-Amp | Analog Devices
MPN: ADA4622-1ARJZ ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.68 | $7.68 |
| 10 | $6.91 | $69.10 |
| 100 | $5.79 | $579.00 |
| 500 | $5.13 | $2,565.00 |
| 1,000 | $4.62 | $4,620.00 |
ADA4622-1ARJZ Overview
A precision op-amp (operational amplifier) is a high-gain DC-coupled analog building block used to amplify small differential signals while rejecting common-mode noise. JFET-input op-amps specifically use junction field-effect transistors at the input pair, which provide extremely high input impedance (typically >1 TΩ) and very low bias current, making them ideal for transimpedance amplifiers, photodiode front-ends, and high-impedance sensor signal conditioning. The ADA4622-1 belongs to the broader category of linear amplifiers -> op-amps -> precision amplifiers -> semiconductor ICs.
Key differentiating features include a maximum offset voltage of just 200 µV, low offset voltage drift of 3 µV/°C, low input capacitance of 6 pF, low noise density of 11 nV/√Hz at 1 kHz, and integrated EMI filtering. The unity-gain stable topology and wide supply range allow operation from a single 5 V rail for portable instrumentation as well as ±15 V for industrial test equipment. Compared to legacy AD820-class JFET op-amps, the ADA4622-1 offers approximately 5x lower noise and 2x lower bias current.
Typical applications include photodiode transimpedance amplifiers, precision current-to-voltage conversion, active filters, instrumentation front-ends, ATE (automatic test equipment) signal conditioning, and high-impedance sensor interfaces for medical and analytical instruments. The SOT-23-5 footprint makes it suitable for high-density PCB designs where PCB real estate is constrained.
When designing with this part, observe the input common-mode range: at +5 V single supply the input range extends from 0 V to approximately +3 V, so for true rail-to-rail sensing above 3 V use the dual ±15 V supply configuration. Place a 100 nF decoupling capacitor directly at the supply pin, and keep input trace lengths short to minimize leakage and parasitic capacitance.
This page synthesizes distributor pricing, drop-in alternative MPNs, and practical SOT-23-5 layout guidance that complements - but does not replace - the Analog Devices datasheet.
Drop-in alternatives for ADA4622-1ARJZ — 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 ADA4622-1ARJZ (same form factor and footprint) — differing in Number of Channels, Output Type, Input Bias Current, Operating Temperature, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ADA4622-1ARJZ-R7
✅ Drop-In✓ In Stock
$3.92 / Unit
View Datasheet →ADA4622-1ARJZ-R2
✅ Drop-In✓ In Stock
$2.62 / Unit
View Datasheet →ADA4622-1ACPZ
✅ Drop-In📋 Reference alternative (not in catalog)
OPA1642AIDR
✅ Drop-In✓ In Stock
$2.88 / Unit
View Datasheet →OPA140AIDR
✅ Drop-In📋 Reference alternative (not in catalog)
ADA4622-1ARJZ Maximum Ratings & Electrical Characteristics
| Manufacturer | Analog Devices Inc. |
| Amplifier Type | JFET Precision Operational Amplifier |
| Number of Channels | 1 |
| Output Type | Rail-to-Rail |
| Supply Voltage (Single) | 5 V to 30 V |
| Supply Voltage (Dual) | ±5 V to ±15 V |
| Gain-Bandwidth Product | 8 MHz |
| Slew Rate | 23 V/µs |
| Input Bias Current (typical) | 2 pA |
| Input Offset Voltage (max) | 200 µV |
| Input Offset Voltage Drift | 3 µV/°C |
| Input Voltage Noise Density | 11 nV/√Hz at 1 kHz |
| Input Capacitance | 6 pF |
| Operating Temperature | -40°C to +125°C |
| Package | 5-Lead SOT-23 (RJ-5) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ADA4622-1ARJZ Pin Configuration
| Pin 1 | OUT — Amplifier output (rail-to-rail) |
| Pin 2 | V- — Negative supply voltage |
| Pin 3 | IN+ — Non-inverting input (JFET, high impedance) |
| Pin 4 | IN- — Inverting input (JFET, high impedance) |
| Pin 5 | V+ — Positive supply voltage |
Typical Applications
ADA4622-1ARJZ is suitable for 6 applications: Photodiode Transimpedance Amplifier, Precision Instrumentation Front-End, Active Filter and Integrator, High-Impedance Sensor Signal Conditioning, Precision Current-to-Voltage Conversion, Automatic Test Equipment (ATE) Pin Driver.
Photodiode Transimpedance Amplifier
The ADA4622-1ARJZ is well suited as the front-end op-amp in a photodiode transimpedance amplifier (TIA) where picoamp-level photocurrents must be converted to a usable voltage with minimal error. Its 2 pA typical input bias current is roughly 50x lower than legacy AD820-class JFET op-amps, meaning the photodiode's dark current sets the noise floor rather than the op-amp's input current. The 8 MHz gain-bandwidth and 23 V/µs slew rate support wideband pulsed detection and high-speed optical communication links, while the 11 nV/√Hz voltage noise density keeps the TIA's output noise below 1 mVrms with a 100 kΩ feedback resistor. Designers should use a feedback capacitor (typically 1-10 pF) to compensate the photodiode's junction capacitance and ensure phase margin above 45°.
Recommended
Precision Instrumentation Front-End
In medical and analytical instrument front-ends - such as ECG leads, pH meters, and mass spectrometer electrometers - the ADA4622-1ARJZ's 200 µV max offset, 3 µV/°C drift, and 2 pA bias current let it accurately amplify millivolt-level signals from high-impedance sources without introducing DC errors. The 5 V to 30 V single-supply operation lets it run directly from a 9 V battery, ±5 V analog rail, or ±15 V industrial supply, simplifying system power design. The integrated EMI filtering reduces susceptibility to RF interference from nearby wireless modules, and the rail-to-rail swing maximizes dynamic range on low-voltage rails. The 8 MHz GBW is ample for audio-frequency physiological signals up to several kHz.
Recommended
Active Filter and Integrator
The ADA4622-1ARJZ serves as the active element in Sallen-Key, multiple-feedback, and integrator filter topologies where its 8 MHz GBW and 23 V/µs slew rate preserve passband flatness and transient response. For example, a 2-pole 20 kHz low-pass Sallen-Key filter using this part achieves less than 0.5 dB passband ripple and 90 dB stopband attenuation, ideal for anti-aliasing before a precision ADC. The JFET inputs present >1 TΩ input impedance so the filter's RC component values are not loaded, preserving design accuracy. The rail-to-rail output lets the filter swing close to either supply on a 5 V rail, maximizing dynamic range in low-voltage systems.
Recommended
High-Impedance Sensor Signal Conditioning
The ADA4622-1ARJZ is an excellent choice for buffering signals from high-impedance sensors including pH probes, ionization chambers, moisture sensors, and piezoelectric transducers where the source impedance may exceed 1 GΩ. The 2 pA bias current produces only microvolts of error across a 1 GΩ source, while the 200 µV offset and 3 µV/°C drift keep DC accuracy within 0.1% over industrial temperature range. A simple unity-gain buffer using the ADA4622-1 presents the sensor's full bandwidth (8 MHz) to downstream instrumentation without loading effects. The 5 V to 30 V supply range lets the same PCB design operate from battery or industrial mains.
Recommended
Precision Current-to-Voltage Conversion
Current-to-voltage (I-to-V) conversion from 4-20 mA industrial loops, photomultiplier tubes, or reference current sources is a classic use of the ADA4622-1ARJZ. With a precision 100 kΩ feedback resistor and a low-bias op-amp like this one, a 4-20 mA loop converts linearly to 0.4-2 V output with better than 0.1% accuracy. The 8 MHz GBW allows the converter to settle within microseconds for multiplexed data-acquisition systems, and the rail-to-rail output maximizes headroom on a single 5 V supply. Designers should add an input TVS for ESD/overvoltage protection on industrial loop inputs.
Recommended
Automatic Test Equipment (ATE) Pin Driver
In ATE and bench instrumentation, the ADA4622-1ARJZ can serve as a unity-gain buffer or non-inverting amplifier for forcing analog voltages onto device under test (DUT) pins with high accuracy. The 2 pA bias and 200 µV offset let it source and sink current without affecting sensitive analog nodes. The 23 V/µs slew rate allows it to slew ±10 V test signals within ~1 µs, keeping test throughput up. The wide ±15 V dual-supply operation covers both legacy TTL/CMOS and modern low-voltage DUT logic levels, while the rail-to-rail output on a 5 V supply handles modern low-voltage DUTs without range switching.
Recommended
Recommended Products Summary
Engineering reference data for ADA4622-1ARJZ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ADA4622-1ARJZ-R7 | ADA4622-1ARJZ-R2 | OPA1642AIDR | OPA140AIDR |
|---|---|---|---|---|---|
| Package | 5-Lead SOT-23 (RJ-5) | 5-Lead SOT-23 (RJ-5) - same | 5-Lead SOT-23 (RJ-5) - same | 8-Pin SOIC - different | 8-Pin SOIC - different |
| Brand | Analog Devices | Analog Devices - same | Analog Devices - same | Texas Instruments | Texas Instruments |
| Channels | 1 | 1 | 1 | 2 | 1 |
| GBW | 8 MHz | 8 MHz | 11 MHz | 11 MHz | |
| Slew Rate | 23 V/µs | 23 V/µs | 20 V/µs | 20 V/µs | |
| Input Bias Current (typ) | 2 pA | 2 pA | 5 pA | 5 pA | |
| Supply Voltage Range | 5 V to 30 V (single) | 5 V to 30 V | 4.5 V to 36 V | 4.5 V to 36 V | |
| Voltage Noise Density | 11 nV/√Hz | 11 nV/√Hz | 12 nV/√Hz | 12 nV/√Hz | |
| Output Type | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail | Rail-to-Rail |
Key Differentiators
- 5x lower voltage noise than legacy AD820 JFET op-amp (vs AD820)
- 50x lower input bias current than AD820 (vs AD820)
- Rail-to-rail output for full 5 V swing on low-voltage rails (vs OPA1642)
Design Notes
The ADA4622-1ARJZ operates from a single 5 V to 30 V supply or dual ±5 V to ±15 V supply. Place a 100 nF X7R ceramic decoupling capacitor within 2 mm of pin 5 (V+) and pin 2 (V-) to keep the high-gain op-amp from oscillating. For dual-supply operation add a bulk 10 µF tantalum or aluminum-polymer capacitor near the supply pins to absorb load transients. The chip's quiescent current is approximately 1 mA per channel so total supply drain is modest; PCB thermal rise is not a concern at SOT-23-5 dissipation levels under 100 mW.
Route the high-impedance JFET inputs (pin 3, pin 4) as short, narrow traces on the top layer surrounded by grounded guard rings to minimize leakage and stray capacitance. Avoid running input traces parallel to switching converter or digital clock traces - keep at least 3x trace-width separation or place a ground plane barrier between them. The SOT-23-5 thermal pad on the bottom of the package should be soldered to a copper pour to keep the part within the 125°C junction limit, even though typical dissipation is well below the 1 W package rating.
Do not assume rail-to-rail input operation at 5 V single supply - per the Analog Devices datasheet the input common-mode range is approximately 0 V to V+ - 2 V, so at +5 V supply the input extends from 0 V to about 3 V. For input signals above 3 V use ±5 V or ±15 V dual supply. Do not omit the feedback resistor when using the part as a buffer; even a unity-gain follower needs the feedback network closed to maintain DC bias on the inverting input. Finally, do not exceed the absolute maximum differential input of ±30 V or latch-up may occur.
Compliance Information
RoHS and lead-free confirmed via Analog Devices product page; no automotive AEC-Q100 grade is offered for this part family.
