AD820ARZ - Single-Supply FET Op Amp | Analog Devices
MPN： AD820ARZ ✓ 啟用中AD820ARZ 概覽
An operational amplifier (op amp) is a high-gain voltage amplifier with differential inputs and a single-ended output, used in signal conditioning, filtering, and mathematical operations. The AD820 belongs to the FET-input op amp family, which uses junction field-effect transistors (JFETs) at the input stage to achieve very high input impedance and low input bias current. This makes it ideal for interfacing with high-impedance sensors and sources without loading them. As a rail-to-rail output device, it can swing its output close to both supply rails, maximizing dynamic range in single-supply systems.
Key features of the AD820ARZ include a low input bias current of 2 pA (typical), low offset voltage of 100 µV (typical), and a supply current of 700 µA per amplifier. It also features a wide input common-mode range that includes the negative rail, enabling it to sense signals near ground in single-supply operation. The device is specified over the industrial temperature range of -40°C to +85°C and is RoHS compliant.
Technically, the AD820 uses a precision bipolar/JFET process, combining the low noise and high speed of bipolar transistors with the high input impedance of JFETs. The output stage is a rail-to-rail class AB design that provides low distortion and high output drive capability. The amplifier is internally compensated for unity-gain stability, simplifying its use in buffer and follower configurations.
Typical applications include battery-powered instrumentation, portable medical devices, sensor signal conditioning, and active filters. Its low power consumption and wide supply range make it particularly suited for portable and industrial equipment where power efficiency and signal integrity are critical.
When designing with the AD820ARZ, ensure proper decoupling of the supply pins with 0.1 µF ceramic capacitors placed close to the device. For best performance, avoid routing high-impedance inputs near noisy traces, and consider using a ground plane to minimize noise pickup.
直接替換替代品，適用於 AD820ARZ — 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： AD820ARZ （相同外形與佔位） — 差異在於 Current - Input Bias, Current - Supply, Gain Bandwidth Product, Operating Temperature, Slew Rate.
AD820BRZ
✅ 直接替換📋 參考替代品（不在目錄中）
AD823ARZ
✅ 直接替換聯絡詢價
查看資料表 →AD820ARZ-REEL7
✅ 直接替換📋 參考替代品（不在目錄中）
TL081
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
MCP6001
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
AD820ARZ 最大額定值與電氣特性
| Amplifier Type | J-FET |
| Number of Circuits | 1 |
| 輸出類型 | Rail-to-Rail |
| Slew Rate | 3 V/µs |
| Gain Bandwidth Product | 1.9 MHz |
| Current - Input Bias | 2 pA |
| Voltage - Input Offset | 100 µV |
| Current - Supply | 700 µA |
| Voltage - Supply Span (Min) | 5 V |
| Voltage - Supply Span (Max) | 36 V |
| 工作溫度 | -40°C to +85°C |
| 封裝 / 外殼 | 8-SOIC (0.154", 3.90mm Width) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
AD820ARZ 腳位配置
| 腳位 1 | OFFSET NULL — Offset null adjustment |
| 腳位 2 | IN- — Inverting input |
| 腳位 3 | IN+ — Non-inverting input |
| 腳位 4 | V- — Negative supply |
| 腳位 5 | OFFSET NULL — Offset null adjustment |
| 腳位 6 | OUT — Output |
| 腳位 7 | V+ — Positive supply |
| 腳位 8 | NC — No connection |
典型應用
AD820ARZ 適用於 6 應用s: Battery-Powered Instrumentation, Portable Medical Devices, Sensor Signal Conditioning, Active Filters, Audio Signal Processing, Industrial Control Systems.
Battery-Powered Instrumentation
The AD820ARZ's low supply current of 700 µA and wide supply range (5 V to 36 V) make it ideal for battery-powered instruments. Its rail-to-rail output maximizes dynamic range, while the FET input ensures minimal loading on high-impedance sensors. In portable multimeters or data loggers, the AD820ARZ can buffer sensor signals with negligible power drain, extending battery life. The low input bias current of 2 pA preserves signal integrity from high-source-impedance transducers, such as pH probes or thermocouples, without additional buffering stages.
推薦
Portable Medical Devices
In portable medical devices like glucose monitors or pulse oximeters, the AD820ARZ provides precise signal conditioning with minimal power consumption. Its low offset voltage (100 µV) ensures accurate measurement of small biosignals, and the rail-to-rail output allows full use of the ADC input range. The wide supply range accommodates battery voltage variations, while the FET input prevents loading of high-impedance electrodes. The AD820ARZ's small 8-SOIC package is suitable for compact, wearable designs, and its industrial temperature range (-40°C to +85°C) ensures reliability in clinical environments.
推薦
Sensor Signal Conditioning
The AD820ARZ excels in sensor signal conditioning due to its ultra-low input bias current (2 pA) and high input impedance, making it ideal for interfacing with high-impedance sensors like photodiodes, piezoelectric sensors, and pH electrodes. Its rail-to-rail output allows direct connection to ADCs without additional level shifting. The 1.9 MHz bandwidth supports moderate-speed sensor signals, while the low offset voltage (100 µV) ensures accurate DC measurements. In industrial applications, the wide supply range (up to 36 V) allows operation from 24 V industrial buses, and the FET input minimizes errors from source resistance.
推薦
Active Filters
The AD820ARZ is well-suited for active filter designs, such as low-pass, high-pass, and band-pass filters, due to its 1.9 MHz gain bandwidth and 3 V/µs slew rate. These specifications allow implementation of filters with cutoff frequencies up to several hundred kilohertz. The rail-to-rail output enables maximum signal swing, and the low input bias current minimizes DC errors in high-impedance filter networks. In audio applications, the low distortion and low noise of the AD820ARZ preserve signal fidelity. Its single-supply operation simplifies filter design in battery-powered equipment, and the wide supply range supports both 5 V and 12 V systems.
推薦
Audio Signal Processing
In audio applications, the AD820ARZ provides clean signal amplification with low distortion and noise. Its 1.9 MHz bandwidth is sufficient for audio frequencies, and the rail-to-rail output allows maximum headroom in single-supply designs. The FET input ensures high input impedance, making it suitable for direct connection to high-impedance sources like electric guitar pickups or condenser microphones. The low supply current (700 µA) is beneficial for portable audio devices, and the wide supply range allows operation from various battery configurations. The AD820ARZ can be used in headphone amplifiers, preamplifiers, and active crossover networks.
推薦
Industrial Control Systems
The AD820ARZ is suitable for industrial control systems, such as process controllers and motor drives, due to its wide supply range (up to 36 V) and robust operating temperature range (-40°C to +85°C). It can interface with sensors and transducers in harsh environments, providing accurate signal conditioning. The rail-to-rail output allows direct connection to ADCs or comparators, and the low input bias current minimizes errors from long sensor leads. In 24 V industrial systems, the AD820ARZ can operate directly from the supply rail without additional regulation. Its low power consumption is advantageous in distributed control nodes.
推薦
推薦產品摘要
工程參考資料，適用於 AD820ARZ — 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 | AD820BRZ | AD823ARZ | TL081 | MCP6001 |
|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC | 8-SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Texas Instruments | Microchip Technology |
| Number of Channels | 1 | 1 | 2 | 1 | 1 |
| Gain Bandwidth Product | 1.9 MHz | 1.9 MHz | 1.9 MHz | 3 MHz | 1 MHz |
| Slew Rate | 3 V/µs | 3 V/µs | 3 V/µs | 13 V/µs | 0.6 V/µs |
| Input Bias Current | 2 pA | 2 pA | 2 pA | 50 pA | 1 pA |
| Supply Current | 700 µA | 700 µA | 700 µA per amp | 1.4 mA | 100 µA |
| Supply Voltage Range | 5 V to 36 V | 5 V to 36 V | 5 V to 36 V | 7 V to 36 V | 1.8 V to 6 V |
主要差異化特點
- Ultra-low input bias current of 2 pA (對比TL081)
- Rail-to-rail output (對比TL081)
- Lower supply voltage operation (對比TL081)
設計說明
For optimal performance, decouple the supply pins with 0.1 µF ceramic capacitors placed as close to the V+ and V- pins as possible. Additionally, a 10 µF tantalum capacitor on the supply line can help filter low-frequency noise. In single-supply operation, ensure the input common-mode range is not exceeded; the AD820ARZ allows inputs down to the negative rail, but not above V+ - 1.5 V.
To minimize noise pickup, use a ground plane and keep high-impedance input traces short and shielded. Avoid routing input traces near digital or switching signals. For best performance, place the AD820ARZ away from heat sources and ensure adequate copper area for heat dissipation, especially in high-temperature environments.
Do not exceed the absolute maximum supply voltage of 36 V. Also, avoid driving capacitive loads greater than 100 pF without a series resistor, as this may cause instability. The offset null pins (1 and 5) can be used to trim offset voltage, but if not used, leave them unconnected. Ensure the input voltage does not exceed the supply rails to prevent latch-up.
合規資訊
RoHS compliant per Analog Devices product page. No AEC-Q100 qualification for this standard op amp.
