ADA4622-1ARJZ - 30V 8MHz Low Bias JFET Op-Amp | Analog Devices
MPN： ADA4622-1ARJZ ✓ 啟用中ADA4622-1ARJZ 概覽
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.
直接替換替代品，適用於 ADA4622-1ARJZ — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： ADA4622-1ARJZ （相同外形與佔位） — 差異在於 Number of Channels, Output Type, Input Bias Current, Operating Temperature, Package.
ADA4622-1ARJZ-R7
✅ 直接替換聯絡詢價
查看資料表 →ADA4622-1ARJZ-R2
✅ 直接替換聯絡詢價
查看資料表 →ADA4622-1ACPZ
✅ 直接替換📋 參考替代品（不在目錄中）
OPA1642AIDR
✅ 直接替換聯絡詢價
查看資料表 →OPA140AIDR
✅ 直接替換📋 參考替代品（不在目錄中）
ADA4622-1ARJZ 最大額定值與電氣特性
| Manufacturer | Analog Devices Inc. |
| Amplifier Type | JFET Precision Operational Amplifier |
| Number of Channels | 1 |
| 輸出類型 | 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 |
| 輸入電容 | 6 pF |
| 工作溫度 | -40°C to +125°C |
| 封裝 | 5-Lead SOT-23 (RJ-5) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
ADA4622-1ARJZ 腳位配置
| 腳位 1 | OUT — Amplifier output (rail-to-rail) |
| 腳位 2 | V- — Negative supply voltage |
| 腳位 3 | IN+ — Non-inverting input (JFET, high impedance) |
| 腳位 4 | IN- — Inverting input (JFET, high impedance) |
| 腳位 5 | V+ — Positive supply voltage |
典型應用
ADA4622-1ARJZ 適用於 6 應用s: 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°.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
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.
推薦
推薦產品摘要
工程參考資料，適用於 ADA4622-1ARJZ — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | 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 |
主要差異化特點
- 5x lower voltage noise than legacy AD820 JFET op-amp (對比AD820)
- 50x lower input bias current than AD820 (對比AD820)
- Rail-to-rail output for full 5 V swing on low-voltage rails (對比OPA1642)
設計說明
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.
合規資訊
RoHS and lead-free confirmed via Analog Devices product page; no automotive AEC-Q100 grade is offered for this part family.
