OPA404SG - Quad 6.4MHz Precision Difet Op Amp | Texas Instruments
部品番号: OPA404SG ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $62.4 | $62.40 |
| 10 | $58.1 | $581.00 |
| 100 | $53.7 | $5,370.00 |
| 500 | $49.3 | $24,650.00 |
| 1,000 | $44.9 | $44,900.00 |
OPA404SG 概要
An operational amplifier is a high-gain differential voltage amplifier that forms the foundational building block of the analog signal chain, sitting within the broader hierarchy of linear amplifiers and amplifier ICs in power management and signal conditioning systems. Quad op amps integrate four independent amplifier channels on a single die, sharing supply pins while keeping inputs and outputs independent, which reduces board area and improves channel-to-channel matching in multi-channel analog designs.
Key features of the OPA404 include a wide 6.4 MHz bandwidth, a fast 35 V/us slew rate, low input bias current of +/-4 pA max enabled by the Difet input cascode architecture, 0.01% settling to fast accuracy, and a standard quad op amp pin configuration that allows direct upgrading of existing designs. The Difet (dielectrically isolated FET) process eliminates the junction-isolation leakage and parasitic capacitance of conventional processes, combining precision input specifications with uncompromised high-speed performance.
The input cascode design keeps the drain-source voltage of the input FETs constant, stabilizing input bias current over temperature and common-mode range while preserving bandwidth. The SG suffix denotes the military-grade temperature rating in a hermetic ceramic package, supporting extended-temperature operation where plastic packaging is unacceptable, such as defense and aerospace instrumentation.
Typical applications include high-speed data acquisition front ends, active filters in test and measurement equipment, precision integrators, photodiode transimpedance amplifiers, and multichannel buffer stages in industrial instrumentation. The quad configuration is particularly efficient in filter topologies such as state-variable designs that require four amplifiers per channel set.
Design consideration: although the 4 pA bias current permits very large feedback resistors, resistor values above approximately 10 megaohm should be evaluated against parasitic capacitance effects on stability; use short feedback traces and consider a small feedback capacitor.
This page synthesizes distributor availability, drop-in alternative analysis, and practical design guidance beyond what the manufacturer datasheet provides.
ドロップイン代替品: OPA404SG — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: OPA404SG （同一形状・フットプリント） — 相違点: Input Type, Mounting Type, Package, Supply Type.
クイック比較ツール — 並列比較する代替部品を選択:
OPA404AG
✅ ドロップイン📋 参考代替品（カタログ未掲載）
OPA404KP
✅ ドロップイン✓ 在庫あり
$23.9 / 個
データシートを見る →OPA404SG/883B
✅ ドロップイン📋 参考代替品（カタログ未掲載）
OPA404SG 最大定格＆電気的特性
| Number of Channels | 4 |
| Bandwidth (-3 dB) | 6.4 MHz |
| Slew Rate | 35 V/us |
| Input Offset Voltage (max) | +/-750 uV |
| Input Bias Current (max) | +/-4 pA |
| Settling Time | 0.01% |
| Total Supply Voltage (max) | 36 V |
| Total Supply Voltage (min) | 10 V |
| Supply Type | Dual supply (e.g. +/-5 V to +/-18 V) |
| Architecture | Difet (dielectrically isolated FET), input cascode |
| Pin Configuration | Standard quad op amp pinout |
| パッケージ | 14-CDIP (ceramic dual-in-line) |
| 実装タイプ | Through-Hole |
| Terminal Count | 14 |
| Temperature Grade | Military grade (SG suffix) |
| Input Type | FET (JFET) input |
| Manufacturer | Texas Instruments (originally Burr-Brown) |
OPA404SG ピン構成
| ピン 1 | 1OUT — Output of amplifier 1 |
| ピン 2 | 1IN- — Inverting input of amplifier 1 |
| ピン 3 | 1IN+ — Non-inverting input of amplifier 1 |
| ピン 4 | V+ — Positive power supply |
| ピン 5 | 2IN+ — Non-inverting input of amplifier 2 |
| ピン 6 | 2IN- — Inverting input of amplifier 2 |
| ピン 7 | 2OUT — Output of amplifier 2 |
| ピン 8 | 3OUT — Output of amplifier 3 |
| ピン 9 | 3IN- — Inverting input of amplifier 3 |
| ピン 10 | 3IN+ — Non-inverting input of amplifier 3 |
| ピン 11 | V- — Negative power supply |
| ピン 12 | 4IN+ — Non-inverting input of amplifier 4 |
| ピン 13 | 4IN- — Inverting input of amplifier 4 |
| ピン 14 | 4OUT — Output of amplifier 4 |
主な用途
OPA404SG の用途: 6 件s: High-Speed Data Acquisition Front End, Active Filter Design, Photodiode Transimpedance Amplification, Defense and Aerospace Instrumentation, Precision Integrator and Sample-Hold Circuits, Test and Measurement Equipment.
High-Speed Data Acquisition Front End
The OPA404SG's 6.4 MHz bandwidth and 35 V/us slew rate make it well suited to amplifying sensor signals ahead of ADCs in high-speed data acquisition systems. Four amplifiers per package allow simultaneous conditioning of multiple input channels with tight channel matching, reducing board area and component count. In a typical design, each channel is configured as a non-inverting buffer or gain stage ahead of a multiplexer or successive-approximation ADC. The 0.01% settling specification ensures the amplifier output stabilizes quickly enough for sampling, and the 4 pA max bias current minimizes error with high-impedance sensor sources. Use supply decoupling of 0.1 uF per supply pin close to the package, and keep analog ground returns separate from digital grounds to preserve the precision offset specification.
おすすめ
Active Filter Design
Quad op amp packages are natural fits for active filter topologies such as state-variable and biquad filters, which require three to four amplifiers per filter section. The OPA404SG's 6.4 MHz gain-bandwidth and 35 V/us slew rate support filters with cutoff frequencies in the hundreds of kilohertz while maintaining low distortion, far beyond what general-purpose quads like the TL074 can achieve. The Difet input with 4 pA max bias current allows large resistor values (megaohm range) in low-frequency filters without significant offset error, reducing capacitor sizes. When designing, verify the amplifier bandwidth is at least 50 to 100 times the filter cutoff frequency to prevent Q degradation, and place the filter gain stages symmetrically on the PCB to control parasitic coupling between high-impedance nodes.
おすすめ
Photodiode Transimpedance Amplification
The OPA404SG's +/-4 pA maximum input bias current, enabled by the Difet dielectrically isolated FET input cascode design, makes each channel an excellent photodiode transimpedance amplifier for optical receivers and light-metering circuits. Low bias current means dark-current errors stay in the picoamp range even with feedback resistors of 1 to 10 megaohm, translating directly to improved sensitivity at low light levels. The 6.4 MHz bandwidth supports megahertz-class optical signal paths, and 35 V/us slew rate prevents slew-induced distortion on fast optical pulses. Stability requires a small feedback capacitor chosen to cancel photodiode capacitance at the summing node; compute Cf from the noise-gain zero formula in the TI datasheet. Reserve one amplifier channel per package for a low-pass reconstruction or comparison stage.
おすすめ
Defense and Aerospace Instrumentation
The SG suffix and hermetic 14-CDIP package position the OPA404SG for military-temperature-grade analog instrumentation, avionics signal conditioning, and defense test equipment where plastic packaging is prohibited by program reliability requirements. The hermetic ceramic package eliminates moisture-related leakage paths that degrade FET-input amplifiers in humid environments, and the /883B variant adds full military screening. Each of the four channels provides 6.4 MHz bandwidth, 35 V/us slew rate, and +/-750 uV max offset for high-accuracy analog computation, filtering, and buffering. Designers should observe through-hole assembly constraints of the CDIP, allow adequate standoff for solder inspection, and verify total supply operation within the 10 V to 36 V range per the TI datasheet before release to production.
おすすめ
Precision Integrator and Sample-Hold Circuits
Integrators and sample-hold circuits demand ultra-low input bias current because any input current charges the integration or hold capacitor, causing droop. The OPA404SG's 4 pA maximum bias current yields droop rates in the microvolt-per-millisecond range with practical capacitor values, and the 35 V/us slew rate allows fast acquisition transitions. The Difet input cascode also stabilizes bias current over common-mode voltage, an advantage over ordinary JFET amplifiers whose bias current varies strongly with input level. For best results, use low-leakage capacitor dielectrics such as polypropylene or C0G/NP0 ceramic, guard the summing node with a driven shield connected to a follower-buffered ground, and select PTFE or clean FR-4 PCB surfaces to minimize board leakage currents that would otherwise dominate the 4 pA input current.
おすすめ
Test and Measurement Equipment
Bench instruments such as oscilloscope front ends, function generators, and data loggers benefit from the OPA404SG's combination of speed and precision across four channels per package. The 6.4 MHz bandwidth and 35 V/us slew rate reproduce fast measurement waveforms, while 0.01% settling supports accurate digitization and the +/-750 uV offset preserves DC measurement accuracy. The standard quad pinout allows instrument designers to upgrade legacy TL074-based signal paths to Difet performance without PCB redesign, a key point stated explicitly in the TI datasheet. The hermetic CDIP through-hole package also suits field-serviceable instruments where through-hole repair is preferred. Apply 0.1 uF ceramic decoupling on both supply pins, and keep high-impedance input traces short and guarded to preserve bias-current performance.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: OPA404SG — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | OPA404AG | OPA404KP | OPA404SG/883B |
|---|---|---|---|---|
| Package | 14-CDIP (through-hole) | 14-DIP (through-hole) | 14-DIP (through-hole) | 14-CDIP (through-hole) - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments (Burr-Brown legacy) |
| Bandwidth | 6.4 MHz | 6.4 MHz | 6.4 MHz | 6.4 MHz |
| Slew Rate | 35 V/us | 35 V/us | 35 V/us | 35 V/us |
| Input Offset Voltage (max) | +/-750 uV | +/-750 uV | +/-750 uV | +/-750 uV |
| Input Bias Current (max) | +/-4 pA | +/-4 pA | +/-4 pA | +/-4 pA |
| Total Supply Range | 10 V to 36 V | 10 V to 36 V | 10 V to 36 V | 10 V to 36 V |
| Temperature Grade | Military (SG) | Commercial (AG) | Commercial/Industrial (KP) | Military with MIL-STD-883 screening |
| Screening / Qualification | Standard hermetic CDIP | None (plastic) | None (plastic) | MIL-STD-883 |
主な差別化要因
- Difet input cascode delivers both speed and precision （vs TL074CN)
- Hermetic military-grade CDIP packaging （vs OPA404KP)
- MIL-STD-883 screened variant available （vs OPA404AG)
設計ノート
Use short, direct feedback traces around each amplifier channel; with 6.4 MHz bandwidth, long feedback loops add inductance and parasitic capacitance that cause peaking or oscillation in gains near unity. Keep high-impedance input nodes (summing junctions, photodiode nodes) as small as possible and surround them with guard rings driven at low impedance. Since the CDIP is through-hole, place decoupling capacitors on the component side directly at pins 4 (V+) and 11 (V-), typically 0.1 uF ceramic per pin plus bulk 4.7-10 uF at the supply entry.
In transimpedance and large-feedback-resistor applications, the junction capacitance of the feedback resistor and input trace capacitance create a noise-gain pole that can destabilize the loop. Estimated: with Rf = 1 megaohm and total input capacitance of 10 pF, a feedback capacitor of a few picofarads is typically needed; compute Cf from the datasheet stability criterion (Cf >= sqrt(Cin/(2*pi*Rf*GBW)) approximation). Verify phase margin on the bench with a square-wave test at the expected signal amplitude given the 35 V/us slew limit.
Do not exceed the 36 V maximum total supply (for example, +/-18 V rails); the 10 V total supply minimum also means single 5 V operation is not supported - this is a dual-supply precision part. When substituting plastic-DIP grades (OPA404AG/KP) for the hermetic SG in high-humidity environments, FET input leakage can rise over life; validate leakage under environmental stress before redesign. For defense programs, confirm whether MIL-STD-883 screening is contractually required and specify OPA404SG/883B explicitly rather than standard SG.
コンプライアンス情報
Ceramic military-grade CDIP legacy part; RoHS/REACH status not stated in the provided data. Hermetic ceramic packaging may be exempt from certain RoHS provisions - verify with TI product pages.
