OPA687U - Wideband Low-Noise Voltage Feedback Op Amp | Texas Instruments
MPN： OPA687U ✗ 停產OPA687U 概覽
An operational amplifier is an analog integrated circuit that amplifies the voltage difference between its inverting and non-inverting inputs. A voltage-feedback amplifier uses feedback to control gain and bandwidth, making it suitable for instrumentation, signal conditioning, active filtering, communications, and high-speed measurement. OPA687U belongs to the broader operational-amplifier hierarchy, which includes instrumentation amplifiers, buffer amplifiers, transimpedance amplifiers, and precision amplifiers.
The OPA687 family is positioned for applications requiring high speed and low noise. The product description specifically identifies the device as a wideband, ultra-low-noise voltage-feedback amplifier with power-down functionality. The power-down feature is useful when a system must reduce current consumption when the signal path is inactive, although the verified data supplied for this page does not include a complete electrical parameter table.
OPA687U is appropriate for high-speed instrumentation, communications interfaces, active filters, video or test signal paths, and analog front ends requiring a wideband voltage-feedback amplifier. The exact gain-bandwidth product, input-noise density, supply-voltage range, input common-mode range, output swing, slew rate, and power-down thresholds were not included in the supplied verified snippets, so those values are not asserted here.
Designers should begin with the manufacturer datasheet for the complete electrical characteristics, recommended operating conditions, pin configuration, and application guidance. In a practical high-speed circuit, short feedback traces, careful grounding, controlled return paths, and suitable decoupling are important. Component selection should also account for the required signal bandwidth, noise performance, output drive, supply rails, operating temperature, and the effect of power-down control on system timing.
This product page combines verified distributor and manufacturer-family information with practical selection guidance. It distinguishes confirmed facts from parameters that require direct confirmation from the OPA687 datasheet, helping engineers evaluate the OPA687U without relying on unverified numerical assumptions.
直接替換替代品，適用於 OPA687U — 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。
OPA847IDR
✅ 直接替換📋 參考替代品（不在目錄中）
OPA687U 最大額定值與電氣特性
| Product Type | Voltage-feedback operational amplifier |
| Circuit Count | 1 circuit |
| Amplifier Family | OPA687 wideband ultra-low-noise operational amplifier |
| Power-Down Function | Present |
| 封裝 | 8-SOIC |
| 安裝類型 | Surface mount |
| Channel Count | 1 |
OPA687U 8-soic 腳位配置指南
OPA687U（8-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： OPA687U.
請參閱 資料表 以查看完整腳位配置。
典型應用
OPA687U 適用於 6 應用s: High-Speed Instrumentation Signal Conditioning, Communications Receive Signal Path, Active Wideband Filtering, Video and Test Signal Amplification, Low-Power-Management Analog Front End, Precision Analog Front-End Buffering.
High-Speed Instrumentation Signal Conditioning
OPA687U fits high-speed instrumentation signal conditioning because the OPA687 family is identified as a wideband, ultra-low-noise voltage-feedback operational amplifier. The device can provide gain and buffering ahead of an ADC when the signal chain requires more bandwidth than a general-purpose precision amplifier. The verified data confirms one amplifier circuit, an 8-SOIC package, and power-down capability, but does not provide the exact gain-bandwidth product or noise density. Designers should use the manufacturer datasheet to select a stable gain, confirm supply and common-mode limits, and determine whether the power-down feature can be tied into a measurement instrument's idle-state control.
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Communications Receive Signal Path
OPA687U is a plausible fit for a communications receive signal path where a wideband, low-noise voltage-feedback amplifier is needed ahead of filtering, conversion, or detection circuitry. Its power-down capability can support systems that periodically enable and disable the analog front end, although the control voltage and timing were not included in the verified data. Exact suitability depends on operating frequency, channel gain, source impedance, and output loading. Engineers should compare the OPA687 datasheet limits with the communications signal-chain requirements and validate gain stability and transient response on the final layout.
推薦
Active Wideband Filtering
OPA687U can be used in active wideband filter stages where the amplifier's wideband voltage-feedback architecture is preferable to a slower precision device. A wideband amplifier allows filter components to determine the useful signal bandwidth while preserving amplitude and phase performance within the amplifier's operating range. The OPA687U's power-down function may reduce consumption when the filter is inactive, but the verified snippets do not state shutdown timing or current. Component values should therefore be calculated from the target transfer function and checked against the manufacturer's recommended operating area and stability guidance.
推薦
Video and Test Signal Amplification
OPA687U is appropriate for video or test-signal amplification when a single-circuit wideband amplifier is required in an 8-SOIC package. The ultra-low-noise family positioning can help preserve small-signal fidelity, while the wideband characteristic supports higher-frequency test points than typical precision amplifiers. Actual video performance depends on gain, output drive, slew rate, and supply range, none of which are numerically present in the supplied verified data. Confirm those values in the OPA687 datasheet and verify output settling and channel-to-channel behavior on the target test equipment.
推薦
Low-Power-Management Analog Front End
OPA687U can fit an analog front end that benefits from a shutdown function when the monitored signal path is not continuously active. The verified manufacturer-family description explicitly includes power down, while DigiKey confirms that OPA687U is a single voltage-feedback amplifier in 8-SOIC. Because the control polarity, shutdown current, and activation time are not supplied, a system-level power controller should not be selected until the datasheet confirms logic levels and timing. This application is best suited to subsystem-level power saving rather than continuous low-power operation.
推薦
Precision Analog Front-End Buffering
OPA687U may be used as the first active stage in an analog front end when signal-source impedance, bandwidth, and noise are more critical than nanopower consumption. Its wideband, ultra-low-noise family characterization supports this use, but the source impedance and sensor output bandwidth must remain compatible with the amplifier's input and feedback network. The verified data does not include input bias current, offset voltage, or common-mode range, so those parameters require direct confirmation. Use short, guarded input routing and validate offset stability before laboratory measurement.
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推薦產品摘要
工程參考資料，適用於 OPA687U — 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 | OPA847IDR |
|---|---|---|
| Package | 8-SOIC | 8-SOIC |
| Brand | Texas Instruments | Texas Instruments |
| Power-Down Function | Present | Optional shutdown pin |
主要差異化特點
- Confirmed power-down-equipped OPA687 positioning (對比OPA847IDR)
- Single-circuit 8-SOIC implementation (對比OPA847IDR)
- Wideband ultra-low-noise family architecture (對比OPA847IDR)
設計說明
Place the input, output, feedback, and supply connections using short traces on the PCB. High-speed feedback loops should have the smallest practical enclosed area, while the input node should be kept away from output and return-current paths. Place supply bypassing close to the relevant pins and use a continuous ground plane so the amplifier's high-frequency return current does not share a narrow path with sensitive input signals.
Check the datasheet-recommended supply range and power-down thresholds before connecting the power control signal. Do not infer that the shutdown input can be tied directly to a system logic rail without confirming its input levels. If the system uses a slow control signal, verify the amplifier's activation and deactivation timing against the measurement or communication protocol requirements.
Do not substitute OPA847IDR solely because it is a wideband, low-noise amplifier in the same family of listed comparison results. Confirm the exact SOIC pin assignments, supply range, input common-mode range, output swing, shutdown polarity, gain-bandwidth product, noise, and stability behavior. Because those values are [DATA_NEEDED: OPA687U and OPA847IDR comparison data], validate any substitution on hardware before production release.
合規資訊
The supplied verified results identify the product, package, amplifier type, family description, and availability references, but do not explicitly provide compliance declarations. Compliance status must be confirmed for the exact orderable OPA687U.
