OPA27GU - Ultra-Low-Noise Precision Op Amp | Texas Instruments
MPN： OPA27GU ✓ 啟用中OPA27GU 概覽
An operational amplifier is an analog integrated circuit that amplifies the voltage difference between its inverting and non-inverting inputs. Precision operational amplifiers add low offset, low drift, high open-loop gain, and strong common-mode and power-supply rejection. The OPA27 belongs to the operational-amplifier hierarchy, which sits within analog ICs and broader semiconductor signal-conditioning systems.
Key features include 4.5 nV/√Hz maximum noise at 1 kHz, 100 µV maximum offset voltage, 0.4 µV/°C maximum input offset drift, 117 dB minimum open-loop gain, 100 dB minimum common-mode rejection, and 94 dB minimum power-supply rejection. Its unity-gain stability supports direct use as a non-inverting buffer, while the precision architecture is useful for low-level sensor and instrumentation signals.
The OPA27GU uses an 8-SOIC package and is identified by DigiKey as a single-circuit standard general-purpose amplifier. The verified part data also associates the family with operation from -40°C to +85°C and an 8 MHz gain-bandwidth product. These characteristics make the device suitable for audio preamplifiers, sensor interfaces, precision filters, measurement front ends, and low-noise analog signal chains.
Designers should verify the complete supply-voltage range, input common-mode limits, output swing, bias current, and stability requirements in the manufacturer datasheet before final circuit release. Decoupling capacitors should be placed close to the supply pins, and the PCB should minimize parasitic capacitance and feedback-loop coupling. The low-noise benefit is realized only when the surrounding resistors, references, layout, and signal source do not dominate the system noise.
This page combines verified manufacturer and distributor information with practical selection, application, and design guidance. It distinguishes the OPA27GU from broader OP27-family alternatives and identifies where a footprint-compatible replacement requires confirmation of electrical and pin-level details before substitution.
直接替換替代品，適用於 OPA27GU — 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： OPA27GU （相同外形與佔位） — 差異在於 Operating Temperature Range, Package, Supply Voltage Range, Mounting Type, Gain-Bandwidth Product.
OPA37GU
✅ 直接替換聯絡詢價
查看資料表 →OPA2277UA
✅ 直接替換 ⚠️ 規格未經驗證聯絡詢價
查看資料表 →OPA227UA
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
OP07AZ/883
✅ 直接替換聯絡詢價
查看資料表 →OP27AJ/883C
✅ 直接替換聯絡詢價
查看資料表 →OPA27GU 最大額定值與電氣特性
| Product Type | Ultra-low-noise precision operational amplifier |
| Input Noise | 4.5 nV/√Hz maximum at 1 kHz |
| Offset Voltage | 100 µV maximum |
| Input Offset Drift | 0.4 µV/°C maximum |
| Open-Loop Gain | 117 dB minimum |
| Common-Mode Rejection | 100 dB minimum |
| Power-Supply Rejection | 94 dB minimum |
| Gain-Bandwidth Product | 8 MHz |
| Gain Stability | Unity-gain stable |
| 工作溫度範圍 | -40°C to +85°C |
| 封裝 | 8-pin SOIC |
| Number of Circuits | 1 amplifier |
| 安裝類型 | Surface mount |
| Product Classification | Standard general-purpose amplifier |
| Manufacturer | Texas Instruments |
| Datasheet Availability | Manufacturer product page and datasheet available |
OPA27GU 8-pin soic 腳位配置指南
OPA27GU（8-pin soic 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： OPA27GU.
請參閱 資料表 以查看完整腳位配置。
典型應用
OPA27GU 適用於 6 應用s: Precision Audio Preamplifier, Low-Level Sensor Signal Conditioning, Precision Instrumentation Amplifier, Active Audio Filter, Precision Reference Buffer, Low-Noise Voltage Amplifier.
Precision Audio Preamplifier
The OPA27GU fits low-level audio preamplification because its verified input noise is 4.5 nV/√Hz maximum at 1 kHz and its unity-gain stability supports direct buffering. Place it near the microphone or line-input source, use low-noise feedback resistors, and bypass the supply pins close to the IC. The amplifier can provide low-voltage-noise amplification for audio signals, while the final system noise remains dependent on source impedance, resistor noise, bandwidth, and gain configuration.
推薦
Low-Level Sensor Signal Conditioning
The OPA27GU is appropriate for amplifying weak sensor signals where input-referred noise and offset can affect measurement resolution. Its verified 100 µV maximum offset and 0.4 µV/°C maximum drift provide useful DC precision, while 4.5 nV/√Hz maximum noise supports low-noise amplification. The circuit should use a sensor-specific input filter, defined gain, local decoupling, and careful grounding to prevent switch-mode and digital circuitry from corrupting the measurement.
推薦
Precision Instrumentation Amplifier
The OPA27GU can serve as a core amplifier in precision instrumentation when the design needs low noise, high open-loop gain, and good rejection of common-mode and supply variations. The verified specifications include 117 dB minimum open-loop gain, 100 dB minimum common-mode rejection, and 94 dB minimum power-supply rejection. A practical implementation should verify resistor matching, gain-bandwidth behavior, input bias current, and output-headroom requirements for the selected sensor and measurement bandwidth.
推薦
Active Audio Filter
The OPA27GU is useful in low-noise active filter stages where signal amplitude is small and component noise can affect the filter response. Its 8 MHz gain-bandwidth product provides bandwidth headroom for moderate-frequency filter designs, while the verified 4.5 nV/√Hz maximum input noise supports low-noise amplification. Select resistor and capacitor tolerances carefully, check phase margin and stability at the intended gain, and keep sensitive filter nodes away from switching regulators and digital return currents.
推薦
Precision Reference Buffer
OPA27GU can buffer a low-level reference or drive a precision measurement input when the source requires low noise and low offset drift. The verified 100 µV maximum offset and 0.4 µV/°C maximum drift are important because reference-buffer errors can directly appear at the ADC or sensor input. Confirm the reference voltage range, output-current capability, capacitive-load stability, and settling requirements in the datasheet before using the amplifier outside laboratory-level conditions.
推薦
Low-Noise Voltage Amplifier
The OPA27GU is appropriate for general low-level voltage amplification in laboratory, industrial, and audio-adjacent signal chains. Its verified high open-loop gain, 100 dB minimum common-mode rejection, and 94 dB minimum power-supply rejection help preserve small differential signals when the circuit is properly configured. The implementation should include input protection, defined gain-setting resistors, supply filtering, and an output-stage check so that the amplifier’s precision is not lost through clipping, loading, or instability.
推薦
推薦產品摘要
工程參考資料，適用於 OPA27GU — 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 | OPA37GU | OPA2277UA | OPA227UA | OP07 | OP27 |
|---|---|---|---|---|---|---|
| Package | 8-SOIC | 8-SOIC candidate; confirm exact suffix | 8-SOIC candidate; confirm exact suffix | 8-SOIC candidate; confirm exact suffix | 8-SOIC candidate; confirm pinout | 8-SOIC candidate; confirm pinout |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Analog Devices |
主要差異化特點
- Low verified input noise (對比OP07)
- Precision offset and drift (對比OP27)
- Unity-gain-stable precision positioning (對比OPA37GU)
設計說明
Keep the OPA27GU input, feedback, and gain-setting paths short and route them away from switching-regulator outputs, relay contacts, and high-current return paths. Place the amplifier close to the protected signal source and use a continuous low-impedance ground reference beneath the analog section. The verified 4.5 nV/√Hz maximum input noise is valuable only when PCB leakage, ground currents, and resistor noise do not dominate the measurement.
Place the supply-bypass capacitors as close as practical to the OPA27GU supply pins, with a short ground return and an adequate analog supply route. Confirm the exact supply-voltage and common-mode limits in the current TI datasheet before selecting bypass values. The supplied data does not include those electrical limits, so capacitor selection must be based on the manufacturer’s recommended application circuit and the actual signal bandwidth.
Do not treat OPA27, OPA37, OP07, and OP27 as automatically interchangeable. Verify the exact suffix, pin names, compensation method, input range, output swing, offset, noise, bias current, and stability for every proposed replacement. A footprint match alone does not guarantee signal-chain compatibility, especially in precision gain stages where a small offset, drift, or bias-current difference can dominate the measurement error.
合規資訊
The verified search data does not provide compliance declarations for the exact OPA27GU ordering code. Confirm current RoHS, REACH, lead-free, halogen-free, conflict-minerals, and automotive qualification status with Texas Instruments or the authorized distributor.