OPA211ID - 1.1nV/Hz Precision Op Amp 80MHz SOIC-8 | TI
MPN： OPA211ID ✓ 啟用中OPA211ID 概覽
An operational amplifier (op amp) is a high-gain voltage amplifier with differential inputs and a single-ended output, a fundamental building block of analog signal chains. Precision op amps such as the OPA211 sit within the amplifier hierarchy: amplifier > operational amplifier > precision op amp, characterized by low offset, low noise, and high open-loop gain. They are essential in instrumentation, medical equipment, and test systems where signal accuracy is critical.
Key features include the 1.1 nV/√Hz input-referred noise density - among the lowest available for a precision op amp - plus a gain-bandwidth product of 80 MHz and 20 V/µs slew rate for high-speed signals. The rail-to-rail output maximizes dynamic range in low-supply designs. DC accuracy is strong with 50 µV typical offset voltage and 60 nA input bias current, and total harmonic distortion plus noise is a very low 0.000015%.
Technically, the OPA211 uses a bipolar input stage with laser trimming to minimize offset and drift. The class-AB output stage provides low distortion and solid capacitive-drive capability. Single (OPA211) and dual (OPA2211) versions exist, with shutdown options on single-channel family members, packaged in SON-8 (3x3 mm), VSSOP-8, and SOIC-8.
Typical applications include low-noise audio preamplifiers, precision instrumentation front ends, active filters, and data-acquisition stages driving high-resolution ADCs such as the ADS1262. The 80 MHz bandwidth also suits photodiode transimpedance amplifiers and RF/IF signal chains.
Design tip: place 0.1 µF ceramic decoupling capacitors close to the supply pins, and respect the input common-mode range to avoid phase reversal. For a second channel, the OPA2211 shares the same performance in one package. Prices as of 2026-08-30.
直接替換替代品，適用於 OPA211ID — 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： OPA211ID （相同外形與佔位） — 差異在於 Input Bias Current, Output Type, Package, Slew Rate.
OPA1611ID
✅ 直接替換📋 參考替代品（不在目錄中）
OPA211AID
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
OPA828IDR
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →AD797ARZ
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LT1028CS8
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
OPA211ID 最大額定值與電氣特性
| 雜訊密度 | 1.1 nV/rtHz |
| Gain-Bandwidth Product | 80 MHz |
| Slew Rate | 20 V/us |
| 靜態電流 | 3.6 mA per amplifier |
| Offset Voltage | 50 uV typical |
| Input Bias Current | 60 nA |
| THD+N | 0.000015% |
| 輸出類型 | Rail-to-Rail Output |
| Stability | Unity-Gain Stable |
| 通道數 | 1 |
| 工作溫度 | -40C to +125C |
| 封裝 | 8-SOIC (D) |
| 安裝類型 | Surface Mount |
| RoHS 狀態 | Compliant |
OPA211ID 腳位配置
| 腳位 1 | TRIM/NC — Offset trim / no connect per package option |
| 腳位 2 | -IN — Inverting input |
| 腳位 3 | +IN — Non-inverting input |
| 腳位 4 | V- — Negative supply |
| 腳位 5 | NC — No connect |
| 腳位 6 | OUT — Output (rail-to-rail) |
| 腳位 7 | V+ — Positive supply |
| 腳位 8 | NC/V+ — No connect or positive supply per package option |
典型應用
OPA211ID 適用於 6 應用s: Low-Noise Audio Preamplifier, Precision Data Acquisition Front End, Photodiode Transimpedance Amplifier, Active Filter and Signal Conditioning, Precision Instrumentation and Test Equipment, RF/IF and Wideband Signal Chains.
Low-Noise Audio Preamplifier
The OPA211's 1.1 nV/√Hz noise and 0.000015% THD+N make it excellent for microphone preamps and line stages where noise floor directly limits dynamic range. Placed as a gain stage between a balanced input and an audio ADC, its rail-to-rail output maximizes headroom on 5V single supplies. Unlike audio-optimized parts, it also provides 80 MHz bandwidth for ultrasonic extension, though the bipolar input's 60 nA bias current requires impedance matching on high-source-resistance inputs.
推薦
Precision Data Acquisition Front End
In data acquisition, the OPA211 amplifies small sensor signals before digitization, using its 50 µV typical offset and 1.1 nV/√Hz noise to preserve low-level resolution. Configured as a gain-of-10 amplifier before a 24-bit ADC, its unity-gain stability and 80 MHz GBW settle quickly, reducing acquisition dead time. A low-pass R-C filter at the ADC input plus 0.1 µF decoupling capacitors at the supply pins keeps the rail clean, per the TI datasheet recommendation for noisy or high-impedance supplies.
推薦
Photodiode Transimpedance Amplifier
The OPA211's 80 MHz gain-bandwidth product supports fast photodiode TIA designs for optical receivers and instrumentation. With feedback resistors in the 10 kOhm to 100 kOhm range, the closed-loop bandwidth remains in the MHz region, and the 1.1 nV/√Hz input noise limits TIA output noise. Because the bipolar input carries 60 nA bias current, designs with very high photodiode impedance should evaluate the FET-input OPA828, while standard optical links benefit from the OPA211's speed and low voltage noise.
推薦
Active Filter and Signal Conditioning
The OPA211 works well in multi-feedback and Sallen-Key active filters up to several MHz, where its 80 MHz GBW ensures the filter's Q and corner frequency stay accurate. The 20 V/µs slew rate handles large-signal filter inputs without slewing distortion, and the rail-to-rail output allows the largest possible signal swing. Placing 0.1 µF plus 1 µF decoupling near each supply pin prevents the high bandwidth from coupling supply noise into the filter passband, a pitfall TI's datasheet explicitly warns about.
推薦
Precision Instrumentation and Test Equipment
In bench instruments and industrial measurement equipment, the OPA211 serves as a low-noise buffer or gain stage for bridge sensors and signal conditioning chains. Its -40C to +125C industrial temperature specification supports harsh environments, while 1.1 nV/√Hz noise preserves measurement resolution at microvolt signal levels. Typical deployment: a gain-of-100 stage ahead of a precision ADC or scope front end; the 60 nA bias current must be balanced by matched source impedances to limit offset error in high-impedance probes.
推薦
RF/IF and Wideband Signal Chains
The OPA211's 80 MHz bandwidth and 20 V/µs slew rate suit IF amplification and wideband buffering in communications receivers. Its 1.1 nV/√Hz voltage noise contributes minimally to system noise figure when driving 50-ohm-terminated IF stages. Placed after a mixer or ahead of a wideband ADC, the amplifier's class-AB output stage drives moderate loads with 0.000015% THD+N, preserving signal purity. Series resistors at the output help isolate capacitive loads and maintain stability at low closed-loop gains.
推薦
推薦產品摘要
工程參考資料，適用於 OPA211ID — 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 | OPA1611ID | OPA211AID | OPA828IDR | AD797ARZ | LT1028CS8 |
|---|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same | 8-SOIC - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Analog Devices |
| Noise Density | 1.1 nV/rtHz | 1.1 nV/rtHz class | 1.1 nV/rtHz | 3.3 nV/rtHz | ~0.9 nV/rtHz | ~0.85 nV/rtHz |
| Quiescent Current | 3.6 mA | ~3.6 mA | 3.6 mA | 4.8 mA | Higher (~8 mA class) | Higher (~10 mA class) |
| Gain-Bandwidth | 80 MHz | 40 MHz class | 80 MHz | 33 MHz class | 110 MHz class | 75 MHz class |
| Rail-to-Rail Output | Yes | Yes | Yes | Yes | No | No |
| Input Bias Current | 60 nA | 60 nA class (bipolar) | 60 nA | pA class (FET) | 250 nA class | 25 nA class |
| Offset Voltage (typ) | 50 uV | 50 uV class | Lower (precision grade) | 45 uV class | 25 uV class | 10 uV class |
主要差異化特點
- Lowest noise per unit current in its class (對比AD797ARZ)
- Rail-to-rail output for maximum dynamic range (對比LT1028CS8)
- Higher bandwidth than audio-optimized sibling (對比OPA1611ID)
設計說明
Decouple both supply pins with 0.1 uF ceramic capacitors placed within 2 mm of the pins, plus a 2.2 uF bulk capacitor per supply rail. TI's OPAx211 datasheet explicitly warns that noisy or high-impedance supplies require decoupling close to the device pins; the 80 MHz bandwidth can otherwise couple supply noise directly into the output.
The bipolar input has 60 nA bias current; on high-impedance sources this creates offset error (60 nA x source resistance). Match source impedances seen by both inputs to cancel bias effects via bias-current cancellation. Also respect the input common-mode range to avoid phase reversal or degraded CMRR near the rails.
At closed-loop gains below 5, capacitive loads above roughly 20-50 pF can degrade phase margin; add a series isolation resistor (10-50 ohm) at the output when driving long cables or ADC input capacitance. For ADC driving, follow the datasheet typical application with an R-C charge kickback filter sized to the ADC sampling rate.
合規資訊
RoHS compliant per DigiKey/TI product listing. Other compliance attributes not stated in provided data.
