OPA277PA - 10µV Precision Op Amp | Texas Instruments
MPN： OPA277PA ✓ 啟用中OPA277PA 概覽
An operational amplifier is an analog signal-conditioning semiconductor that amplifies the voltage difference between its two inputs and drives the output from that difference. The OPA277 family belongs to the precision operational-amplifier hierarchy, which sits within analog amplifiers, analog ICs, and broader semiconductor systems. Unlike general-purpose amplifiers, precision operational amplifiers are optimized to minimize input-referred error over time, temperature, and supply variation.
The OPA277 series is described by Texas Instruments as an improved replacement for the industry-standard OP-177. Its stated advantages include improved noise performance, a wider output-voltage swing, twice the speed of the compared device, and half the quiescent current. These characteristics make the OPA277PA suitable for bridge and strain-gauge front ends, precision current measurement, laboratory instrumentation, sensor interfaces, and buffered references where offset error directly limits accuracy.
OPA277PA is a single-amplifier device in a through-hole PDIP-8 package, allowing straightforward prototyping, socketed construction, and repair. The product listing identifies a nominal gain-bandwidth product of 1 MHz and slew rate of 0.8 V/µs. Its bipolar architecture operates from a total supply range of 2 V to 18 V, with 5 V to 15 V single-supply operation also identified in the component specifications. The maximum supply rating is 36 V.
Common applications include precision bridge excitation, pressure and force sensing, laboratory buffer stages, low-level signal conditioning, and analog measurement systems. The 10 µV input offset and 0.1 µV/°C drift are particularly useful when long measurement paths or changing temperatures could otherwise obscure small sensor signals. Input bias current must still be considered in high-impedance source designs because it creates source-dependent voltage error.
When designing around the OPA277PA, keep the input and output operating points within the device's common-mode and output-swing limits. Place input and feedback components close to the pins, use stable resistor networks for gain and offset calibration, and decouple each supply rail near the device. Avoid substituting a rail-to-rail amplifier without checking input bias current, offset, drift, noise, bandwidth, and supply behavior.
This page combines device specifications, application guidance, pin and package considerations, and a conservative replacement assessment. It distinguishes true footprint-compatible choices from package or function variants that would otherwise appear in broad cross-reference results but may require PCB or circuit changes.
直接替換替代品，適用於 OPA277PA — 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。
此產品無可直接替換的替代品。
申請替代品OPA277PA 最大額定值與電氣特性
| Amplifier Type | Single bipolar precision operational amplifier |
| Number of Circuits | 1 circuit |
| Maximum Supply Voltage | 36 V |
| 工作電源電壓 | 2 V to 18 V |
| Single-Supply Operating Range | 5 V to 15 V |
| Input Offset Voltage | 10 µV |
| Input Offset Voltage Drift | 0.1 µV/°C |
| Gain-Bandwidth Product | 1 MHz |
| Slew Rate | 0.8 V/µs |
| 工作溫度範圍 | -40 °C to +85 °C |
| 封裝 | 8-pin PDIP (P) |
| 安裝類型 | Through-hole |
| Process Technology | Bipolar |
OPA277PA 8-pin pdip (p) 腳位配置指南
OPA277PA（8-pin pdip (p) 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： OPA277PA.
請參閱 資料表 以查看完整腳位配置。
典型應用
OPA277PA 適用於 6 應用s: Strain-Gauge and Bridge Sensor Front Ends, Precision Current Measurement, Laboratory Instrumentation Buffers, Low-Level Sensor Signal Conditioning, Precision Voltage Reference Buffering, Analog Test and Measurement Systems.
Strain-Gauge and Bridge Sensor Front Ends
OPA277PA fits precision bridge-amplifier input stages because its 10 µV offset voltage and 0.1 µV/°C offset drift help preserve the small differential signals produced by strain gauges and resistive bridges. The 1 MHz gain-bandwidth product supports closed-loop gains commonly used in low-frequency force, pressure, and load measurements. Place the amplifier close to the bridge excitation and feedback network to minimize parasitic pickup. Because input bias current still creates error with high-impedance sources, verify source impedance and use guarding where necessary.
推薦
Precision Current Measurement
OPA277PA is suitable for precision current-to-voltage and transimpedance measurements when low offset and low drift are needed to distinguish a small measured current from sensor and amplifier errors. Its 36 V maximum supply rating provides headroom for laboratory and industrial measurement systems, while the 0.8 V/µs slew rate helps preserve transient response. The designer should account for input bias current, current-noise density, feedback-node capacitance, and the amplifier’s output-swing limits when setting the gain.
推薦
Laboratory Instrumentation Buffers
OPA277PA works well as an input or output buffer in laboratory instruments where source impedance and component tolerance can otherwise create measurement drift. Its 10 µV offset and 0.1 µV/°C drift reduce signal-path uncertainty over changing bench temperatures, while the 1 MHz bandwidth is appropriate for many low-frequency instrumentation channels. Keep feedback loops short, use stable resistors, and avoid driving long capacitive loads without an isolation resistor because added phase lag can undermine stability.
推薦
Low-Level Sensor Signal Conditioning
OPA277PA can condition low-level outputs from sensors where offset voltage and thermal drift determine the useful resolution of the complete measurement chain. The device’s 10 µV offset specification is useful for millivolt-level sensor signals, and its low-bias-current architecture supports relatively high source impedances. Confirm the exact bias-current and noise figures in the datasheet for the selected temperature and supply conditions. Calibration should separate amplifier offset from sensor offset so production trimming remains practical.
推薦
Precision Voltage Reference Buffering
OPA277PA can buffer a low-current reference node when the reference source cannot directly drive the required load. The low offset and drift reduce errors added between the reference element and the following converter or measurement circuit. Its 1 MHz bandwidth and 0.8 V/µs slew rate provide useful response for modest load changes, although the output-current capability, capacitive-load stability, and output swing must be checked before use. A dedicated reference buffer may offer lower offset in specialized designs.
推薦
Analog Test and Measurement Systems
OPA277PA is appropriate for analog test equipment requiring stable gain and low dc error across repetitive measurements. Its offset drift of 0.1 µV/°C supports consistent readings when equipment temperature varies, and the PDIP package simplifies breadboard, socket, and legacy test-system assembly. For multichannel systems, evaluate offset matching between devices, resistor-network drift, input protection recovery, and channel-to-channel crosstalk. These system-level effects can dominate otherwise excellent amplifier specifications.
推薦
推薦產品摘要
工程參考資料，適用於 OPA277PA — 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 |
|---|---|
| Brand | Texas Instruments |
| Package | 8-pin PDIP (P) |
| Amplifier Type | Single bipolar precision operational amplifier |
| Maximum Supply Voltage | 36 V |
| Operating Supply Voltage | 2 V to 18 V |
| Input Offset Voltage | 10 µV |
| Input Offset Voltage Drift | 0.1 µV/°C |
| Gain-Bandwidth Product | 1 MHz |
| Slew Rate | 0.8 V/µs |
| Operating Temperature Range | -40 °C to +85 °C |
主要差異化特點
- Precision dc-error characteristics (對比OPA202)
- Through-hole package supports serviceable and prototype assemblies (對比OPA277UA)
- Family-level upgrade over the OP-177 architecture (對比OP-177)
設計說明
Keep the input, feedback, and gain-setting components close to the OPA277PA pins. High-impedance input traces can collect leakage and interference, so use guarded routing where possible and keep the grounded copper plane away from sensitive input nodes. Place the positive and negative supply-decoupling capacitors close to their respective pins and connect each capacitor directly to the ground plane to minimize supply-current-loop inductance.
Do not assume that every OPA277-family ordering code is a drop-in substitute. OPA277PA uses an 8-pin PDIP package, while OPA277UA is associated with SOIC packaging and may represent a different channel configuration. Before substitution, compare the physical outline, pin numbering, input and output assignments, supply pins, exposed connections, and every dc and dynamic limit relevant to the design.
The OPA277PA has a 1 MHz gain-bandwidth product, so closed-loop bandwidth changes with noise gain and must be checked at the intended operating frequency. Avoid driving a capacitive load directly unless the manufacturer’s stability guidance permits it. If capacitive loading is unavoidable, add a small isolation resistor close to the output and verify phase margin and transient response on the completed board.
Account for quiescent current and output-current demand when designing the supply path, because neither figure is established for this orderable configuration in the available technical summary. Use the manufacturer datasheet for maximum quiescent current, output-current capability, output swing, and common-mode limits. A supply can meet its nominal voltage while still producing inaccurate operation if the amplifier cannot maintain the required output level.
合規資訊
No explicit RoHS, REACH, lead-free, halogen-free, or conflict-minerals declarations were identified for OPA277PA in the available technical information. AEC-Q100 qualification is not indicated.