OPA228U - Precision Low-Noise Op Amp | Texas Instruments
料号： OPA228U ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $3.5508 | $3.55 |
| 10 | $3.55 | $35.50 |
| 100 | $3.45 | $345.00 |
| 500 | $3.35 | $1,675.00 |
| 1,000 | $3.25 | $3,250.00 |
OPA228U 概述
An operational amplifier is an analog integrated circuit that amplifies the voltage difference between its inverting and non-inverting inputs while using negative feedback to set the closed-loop gain. The OPA228 belongs to the precision amplifier hierarchy, combining low-noise voltage amplification with accurate DC behavior. Its high precision makes it useful when small sensor signals must be amplified without adding substantial offset, drift, or common-mode error.
The main features of the OPA228U include 3 nV/√Hz noise density, a 10 V/µs slew rate, and settling time listed in the manufacturer’s data. The device is intended for high-gain closed-loop configurations, where its precision and bandwidth provide useful signal fidelity. The verified distributor data identifies the part as a single amplifier in an 8-SOIC package and lists ±18 V to ±36 V operating capability.
OPA228 devices are designed for applications requiring both AC and precision DC performance. The family combines low noise with high open-loop gain and strong common-mode rejection, helping preserve weak signals in systems where environmental offsets and interference matter. Because this is an analog precision component, supply layout, grounding, input bias-current compensation, and stable feedback components remain important in a complete design.
Typical uses include sensor-signal conditioning, precision current and voltage measurement, laboratory instrumentation, audio preamplification, and low-level analog front ends. The OPA228U can be useful where a gain of approximately 5 or higher is appropriate, while applications requiring unity-gain stability should review the family details and choose the OPAx227 rather than assume interchangeability.
Designers should check the complete manufacturer data sheet for input common-mode limits, output swing, bias current, offset voltage, supply-current behavior, and compensation requirements before finalizing a circuit. In particular, the 8-pin SOIC footprint requires careful attention to pin orientation and feedback routing.
This page combines verified manufacturer and distributor information, package data, source links, and engineering-focused selection guidance to make OPA228U evaluation more actionable than a basic distributor listing alone.
直接替换替代料： OPA228U ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： OPA228U （相同外形与封装尺寸） ——差异在于 Package, Slew Rate.
快速对比工具——选择替代料号进行并排对比：
OPA227UA
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
OPA227UA/2K5
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
OPA227U
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$2.05 / 个
查看数据手册 →OPA227UK
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
OPA227UA/2K5
✅ 直接替换 ⚠️ 规格未核验📋 参考替代料（不在目录中）
OPA228U 最大额定值与电气特性
| Product Type | Precision operational amplifier |
| Number of Circuits | 1 |
| Supply Voltage Range | ±18 V to ±36 V |
| Maximum Total Supply Voltage | 36 V |
| 噪声密度 | 3 nV/√Hz |
| Slew Rate | 10 V/µs |
| Common-Mode Rejection | 138 dB |
| Settling Time | 5 µs |
| Recommended Closed-Loop Gain | 5 or greater |
| 封装 | 8-pin SOIC |
| 安装类型 | Surface mount |
| Channel Count | 1 |
OPA228U 8-pin soic 引脚配置指南
OPA228U（8-pin soic 封装）的引脚配置。 该模拟元件具有输入、输出和电源引脚。请参阅制造商数据手册以了解失调调零、补偿和使能引脚配置。适用于信号调理和放大器电路。
暂无详细引脚数据： OPA228U.
请参阅 数据手册 以查看完整引脚配置。
典型应用
OPA228U 适用于 6 应用s: Precision Sensor Signal Conditioning, Precision Voltage Measurement, Instrumentation and Test Equipment, Audio Preamplification, Low-Level Analog Front End, Industrial Control Signal Interface.
Precision Sensor Signal Conditioning
OPA228U fits low-level sensor front ends because its verified noise density is 3 nV/√Hz and its family is designed for precision AC and DC performance. Place the amplifier in a non-inverting or inverting conditioning topology with a closed-loop gain of approximately 5 or greater, matching the OPA228 optimization. The main design consideration is that source impedance, resistor noise, bias-current error, and offset drift can dominate the final accuracy. Keep feedback resistors close to the device, use a stable reference, and verify common-mode and output-swing limits against the complete Texas Instruments datasheet.
推荐
Precision Voltage Measurement
OPA228U is appropriate for precision voltage-measurement buffers and amplifiers where the measured level is small relative to the available supply rails. Its 138 dB common-mode rejection helps reduce error when the signal shares a varying reference with the measurement system, while the 3 nV/√Hz noise specification supports low-amplitude signal chains. Use gain carefully: the OPA228 family is optimized for gains of 5 or greater, so verify settling time and stability for the selected feedback network. Precision resistors, low-leakage PCB materials, and calibrated references are as important as the op amp itself.
推荐
Instrumentation and Test Equipment
OPA228U can serve as the analog gain stage in laboratory instrumentation, process monitoring, and measurement equipment. Its combination of low noise, high common-mode rejection, and high closed-loop optimization is useful when amplifying weak differential signals before an ADC or measurement converter. A practical implementation should use a grounded or properly referenced input network, short feedback traces, and decoupling close to the supply pins. Because the verified data does not provide full offset, bias-current, and temperature specifications, the complete manufacturer datasheet should be used for calibration and error-budget calculations.
推荐
Audio Preamplification
OPA228U is suitable for low-noise audio preamplifier stages where accurate signal reproduction and low broadband noise are more important than minimum cost. The verified 3 nV/√Hz noise specification provides a useful starting point, while the 10 V/µs slew rate supports signal transitions in higher-bandwidth audio paths. The OPA228 is optimized for gains of 5 or greater, which is compatible with many preamplifier stages, but output swing and stability must be checked against the selected supply voltage. Use clean ground returns, short output routing, and stable feedback resistors.
推荐
Low-Level Analog Front End
OPA228U can be used in a low-level analog front end when a design needs both AC bandwidth and precision DC behavior. The family’s wide bandwidth and slew-rate capability make it useful ahead of filters, converters, or control loops, while its noise and rejection characteristics help preserve weak signals. Select the feedback network and compensation strategy for the intended closed-loop gain rather than copying a generic circuit. In a mixed-signal PCB, keep the analog return path continuous, bypass supply rails near the amplifier, and avoid routing high-current switching nodes beneath sensitive input traces.
推荐
Industrial Control Signal Interface
OPA228U is appropriate for industrial control interfaces that condition low-level command or feedback signals. The 138 dB common-mode rejection can help maintain signal integrity when the input shares ground noise or a slowly varying common-mode voltage with the amplifier, and the precision-oriented architecture supports accurate control-loop measurements. The OPA228U’s higher-gain optimization should be matched to the loop’s gain-bandwidth requirements. Validate noise, offset, temperature drift, supply range, and output current against the final industrial operating environment before production release.
推荐
推荐产品汇总
工程参考数据： OPA228U ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | OPA227UA | OPA227UA/2K5 | OPA227U | OPA227UK | OPA227UA/2K5 |
|---|---|---|---|---|---|---|
| Package | 8-pin SOIC | SOIC-8 | SOIC-8 | SOIC-8 | SOIC-8 | SOIC-8 |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Closed-Loop Gain Optimization | 5 or greater | Unity-gain stable | Unity-gain stable | Unity-gain stable | Unity-gain stable | Unity-gain stable |
| Application Category | Precision AC and DC amplification | Precision amplifier; verify exact specifications | Precision amplifier; verify exact specifications | Precision amplifier; verify exact specifications | Precision amplifier; verify exact specifications | Precision amplifier; verify exact specifications |
关键差异点
- OPA228U is specifically optimized for closed-loop gains of 5 or greater. （对比 OPA227UA)
- Verified noise density is 3 nV/√Hz. （对比 OPA227UA)
- OPA228U combines low noise with 138 dB common-mode rejection. （对比 OPA227UA)
- The 10 V/µs slew rate supports faster signal transitions. （对比 OPA227UA)
设计说明
Keep the OPA228U input and feedback traces short and route them away from clocks, switching inductors, and high-current return paths. The verified 3 nV/√Hz noise figure is a device specification, not a complete PCB noise budget; resistor thermal noise, input-source impedance, leakage, and ground currents can become the dominant contributors. Use a continuous analog ground region and place input filtering close to the source when cable or sensor noise is present.
Place supply bypass capacitors close to the OPA228U supply pins and provide a low-impedance return for each capacitor. Keep the feedback resistors and any compensation components close to the relevant input pins, and avoid routing the sensitive input over the package ground or thermal relief if the application requires low-noise behavior. Confirm the exact 8-SOIC pinout from the Texas Instruments datasheet before layout release.
Do not select OPA228U solely because it has low noise and a wide supply range. The OPA228 family is optimized for closed-loop gains of 5 or greater, whereas the related OPA227 family is described as unity-gain stable. Also verify input common-mode range, output swing, bias current, offset, temperature range, and load capability from the complete manufacturer datasheet before treating any family member as a substitute.
The available verified data is incomplete for offset voltage, input bias current, operating temperature, exact alternative parameters, and compliance status. Those values must not be inferred from the OPA228 family description. During schematic review, mark them as datasheet-dependent and compare the selected OPA228U ordering code against the actual production requirements.
合规信息
Compliance information was not explicitly provided in the verified web data. Do not infer RoHS, REACH, lead-free, halogen-free, conflict-minerals, or automotive qualification from the product category.