OPA350PA - 38MHz Low-Noise Rail-to-Rail Op Amp | Texas Instruments
MPN： OPA350PA ✓ 啟用中OPA350PA 概覽
A rail-to-rail operational amplifier is an amplifier whose useful input and output ranges extend close to the positive and negative supply rails. This input/output characteristic supports wider signal swing than a conventional amplifier whose linear input range is limited by internal biasing. In the system hierarchy, the OPA350PA belongs to the operational-amplifier class of analog and linear ICs used for buffering, amplification, filtering, and feedback control.
The OPA350PA combines 38 MHz gain-bandwidth product with a 22 V/us slew rate, allowing it to process high-frequency signals without requiring a high-voltage supply. Its 5 nV/sqrt(Hz) input-noise specification is particularly useful when low-level signals must be amplified before conversion or measurement. Rail-to-rail output can swing within 10 mV of the relevant output limits under the operating conditions described by the manufacturer. These characteristics make the device suitable for sampling analog-to-digital converter inputs, cell-phone power-amplifier control loops, and other compact, bandwidth-sensitive analog circuits.
The OPA350 series uses a CMOS operational-amplifier architecture optimized for single-supply operation over a 2.7 V to 5.5 V supply range. Its combination of wide bandwidth, high slew rate, and low noise provides more design flexibility than either a general-purpose slow amplifier or a high-speed amplifier with higher noise. Gain can be established with conventional external resistors, while signal conditioning is supported by the amplifier's low-noise input stage and broad output-driving capability.
Typical uses include driving sampling analog-to-digital converters, closing cell-phone power-amplifier control loops, amplifying sensor signals, buffering high-impedance sources, and implementing active analog filters. The device is especially appropriate when the system operates from a single low-voltage rail and needs both input and output signal range close to the supply limits. When driving a converter, input settling and the converter's acquisition requirements should be checked together.
The principal design consideration is power-supply decoupling. Place the supply-bypass capacitor close to the amplifier's power and ground pins, keep feedback components compact, and route high-frequency current in a short loop. Because a fast amplifier can expose poor grounding or long feedback paths, maintain a low-impedance return path and verify the completed circuit with an oscilloscope before relying on calculated phase margin.
This page consolidates the manufacturer's functional description, package information, ordering identifiers, practical application guidance, and verified source links. It also distinguishes the electrically and mechanically suitable drop-in alternatives from parts that merely appear in general cross-reference results, helping engineers avoid a replacement that changes the PCB footprint or signal behavior.
直接替換替代品，適用於 OPA350PA — 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： OPA350PA （相同外形與佔位） — 差異在於 Amplifier Type, Gain-Bandwidth Product, Package, Slew Rate.
此產品無可直接替換的替代品。
申請替代品OPA350PA 最大額定值與電氣特性
| Amplifier Type | Single operational amplifier |
| Architecture | CMOS operational amplifier |
| Supply Configuration | Single supply |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Gain-Bandwidth Product | 38 MHz |
| Slew Rate | 22 V/us |
| Input Noise Voltage Density | 5 nV/sqrt(Hz) |
| Input Common-Mode Range | Rail-to-rail |
| 輸出電壓範圍 | Rail-to-rail, within 10 mV |
| Total Harmonic Distortion plus Noise | 0.0006% |
| Number of Amplifiers | 1 |
| 腳位數 | 8 |
| 封裝 | 8-pin PDIP, 0.300 inch (7.62 mm) pitch |
| 安裝類型 | Through-hole |
| Product Category | Standard general-purpose amplifier |
OPA350PA 8-pin pdip, 0.300 inch (7.62 mm) pitch 腳位配置指南
OPA350PA（8-pin pdip, 0.300 inch (7.62 mm) pitch 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： OPA350PA.
請參閱 資料表 以查看完整腳位配置。
典型應用
OPA350PA 適用於 6 應用s: Sampling ADC Input Driver, Cell-Phone Power-Amplifier Control Loop, Low-Level Sensor Signal Conditioning, Active Analog Filter, High-Speed Buffer Stage, Portable Instrumentation Front End.
Sampling ADC Input Driver
The OPA350PA is well matched to a sampling ADC input because its 38 MHz gain-bandwidth product and 22 V/us slew rate provide the speed needed to settle between conversion cycles. Its 5 nV/sqrt(Hz) input-noise density is also favorable when the ADC must resolve low-amplitude signals. Place the amplifier close to the converter, use short feedback paths, and confirm the converter's acquisition time and required settling accuracy for the selected gain. Check the ADC input range against the OPA350PA's rail-to-rail capability and the intended single 2.7 V to 5.5 V supply.
推薦
Cell-Phone Power-Amplifier Control Loop
OPA350PA is suitable for compact RF power-amplifier control loops because its 22 V/us slew rate responds to rapidly changing control signals and its 38 MHz bandwidth supports higher-frequency loop dynamics. The 5 nV/sqrt(Hz) noise density helps avoid adding excess noise to low-level feedback signals. Single-supply operation from 2.7 V to 5.5 V aligns with portable-system constraints, while rail-to-rail input and output operation increases usable signal range. Validate loop stability, RF coupling, grounding, and component tolerances in the final board rather than relying only on small-signal equations.
推薦
Low-Level Sensor Signal Conditioning
OPA350PA can condition low-level sensor signals where bandwidth is needed alongside low input noise. Its 5 nV/sqrt(Hz) noise density is lower than the noise expected from many general-purpose amplifiers, while the 38 MHz gain-bandwidth product prevents the amplifier from becoming the dominant bandwidth limitation in moderate-speed sensor systems. Use a single supply within 2.7 V to 5.5 V and verify that the sensor's common-mode voltage remains inside the amplifier's rail-to-rail input range. Keep sensor traces away from clocked and switching circuitry to preserve the practical benefit of the low-noise specification.
推薦
Active Analog Filter
OPA350PA is appropriate for active filtering when a 5 V system needs more bandwidth than ordinary low-noise amplifiers provide. Its 38 MHz gain-bandwidth product and 22 V/us slew rate support higher-order filter sections and wider signal bands, while rail-to-rail input and output improve dynamic range near the supply limits. Select resistor and capacitor values that place the closed-loop bandwidth and phase margin in suitable ranges, and test the filter at the actual source and load impedances. The amplifier's high speed can also amplify layout parasitics, so component placement and grounding should be reviewed alongside frequency-response measurements.
推薦
High-Speed Buffer Stage
OPA350PA can buffer a source into a following measurement or conversion stage when the source requires rail-to-rail input range and rapid voltage changes. The 22 V/us slew rate reduces large-signal distortion when driving moderate capacitance, while 38 MHz gain-bandwidth product supports unity-gain buffering at higher frequencies than typical general-purpose devices. Verify capacitive stability with the exact load, output amplitude, and frequency, and use the manufacturer's test or evaluation layout for guidance. In instrumentation applications, isolate the buffer from digital switching paths to avoid coupling noise into the signal being measured.
推薦
Portable Instrumentation Front End
OPA350PA fits a portable measurement front end that operates from a single low-voltage supply and must process signals at appreciable speed. Its 2.7 V to 5.5 V operating range, 5 nV/sqrt(Hz) input noise, and rail-to-rail I/O behavior allow the front end to use much of the available signal range. The 38 MHz bandwidth also makes the amplifier useful for sensors whose output must be conditioned before sampling. Power the analog section from a clean rail, decouple close to the device, and keep sensitive input routes away from processors and switching converters to preserve the intended low-noise performance.
推薦
推薦產品摘要
工程參考資料，適用於 OPA350PA — 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 |
|---|---|
| Package | 8-pin PDIP, 0.300 inch (7.62 mm) pitch |
| Brand | Texas Instruments |
| Amplifier Type | Single CMOS operational amplifier |
| Supply Configuration | Single supply |
| Supply Voltage Range | 2.7 V to 5.5 V |
| Gain-Bandwidth Product | 38 MHz |
| Slew Rate | 22 V/us |
| Input Noise Voltage Density | 5 nV/sqrt(Hz) |
| Input Common-Mode Range | Rail-to-rail |
| Output Voltage Range | Rail-to-rail, within 10 mV |
| Total Harmonic Distortion plus Noise | 0.0006% |
| Number of Pins | 8 |
主要差異化特點
- Combines high speed, low noise, and single-supply rail-to-rail operation (對比OPA340UA)
- Optimized specifically for high-speed sampling-ADC drive (對比OPA350EA/250)
- Uses an 8-pin PDIP format for through-hole assembly (對比OPA350EA/250)
設計說明
Place the supply-bypass capacitor directly between the OPA350PA power and ground pins, and keep the loop as compact as possible. Use a short ground return that does not force high-frequency current through a long shared trace. With 38 MHz bandwidth and 22 V/us slew rate, the amplifier can react quickly to parasitic inductance and shared-impedance noise. Follow the capacitor value and layout guidance in the Texas Instruments OPA350 datasheet, then verify supply ripple at the device pins with an oscilloscope.
Keep the noninverting and inverting inputs, feedback resistors, and output route compact to minimize parasitic inductance and capacitance. These effects become more consequential as closed-loop bandwidth approaches the amplifier's 38 MHz gain-bandwidth product. For sampling-ADC designs, calculate settling from the required gain, ADC acquisition time, and noise gain, then test the assembled board at the intended signal amplitude and clock rate. Do not use only nominal bandwidth as evidence that the converter will acquire an accurate result.
Do not assume that every OPA350-series ordering code is a mechanical substitute for OPA350PA. The PA ordering code specifies the 8-pin PDIP configuration, while other suffixes denote different packages. Likewise, a lower-noise amplifier in another series may have a different pinout, supply range, stability profile, or output behavior. Before substituting a part into an existing board, verify the exact footprint, all pin names, electrical limits, exposed thermal requirements, and stability for the actual feedback network.
Although OPA350PA operates from a low single supply, dissipation increases with output current, output voltage, supply voltage, and operating frequency. Estimate worst-case dissipation using the actual load and quiescent current, then compare the resulting junction temperature with the manufacturer's operating limits. Through-hole construction aids heat transfer, but board placement and copper area still influence thermal performance. Keep heat-producing regulators and digital stages away from precision analog sections to limit both temperature drift and local noise coupling.
合規資訊
No explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declaration was identified for OPA350PA in the referenced product information. Confirm current declarations for the exact orderable part and manufacturing site with the manufacturer before making a compliance claim.
