OPA643P - Wideband Low-Distortion Op Amp | Texas Instruments
MPN: OPA643P ✓ فعالOPA643P جائزہ
A voltage-feedback operational amplifier is an analog active device that amplifies the difference between two input voltages while presenting a high input impedance and a low output impedance. The "voltage-feedback" architecture (as opposed to current-feedback) is characterized by a constant gain-bandwidth product, meaning that as closed-loop gain increases, usable bandwidth decreases proportionally. This topology sits within the broader hierarchy: operational amplifier -> analog amplifier -> amplifier IC -> integrated circuit -> semiconductor. The "P" suffix in the OPA643P designation specifically identifies the PDIP-8 plastic through-hole package, distinguishing it from surface-mount variants such as the OPA643N (SOIC-8) and OPA643U (SOT-23-5).
Key features include low distortion specified at 5 MHz, 2.3 nV/√Hz input voltage noise density, 800 MHz gain-bandwidth product, 1000 V/µs slew rate, and stability for gains of 3 or higher. The wide supply range of ±5.5 V (11 V total) makes the device compatible with typical ±5 V analog rails. Its high open-loop gain and excellent DC precision support demanding instrumentation applications that require both wideband AC performance and accurate low-frequency operation.
The OPA643P is built on a high-speed complementary bipolar process, which is the underlying technology enabling the combination of high slew rate, low noise, and low distortion. The internal topology is fully compensated for unity-gain stability, and external feedback components set the closed-loop response. Designers can exploit the high gain-bandwidth product for wideband transimpedance and ADC-driver applications, while the low-distortion characteristic suits communications IF stages, video buffers, and high-fidelity audio line drivers.
Typical applications include wideband instrumentation amplifiers, low-distortion ADC input buffers, high-speed line drivers, video amplifier stages, communications IF amplifier blocks, and active filters. The device is also frequently deployed in test and measurement front-ends, medical imaging analog front-ends, and high-speed transimpedance amplifiers for photodiode interfaces.
When designing with the OPA643P, attention to PCB layout is critical because the 800 MHz gain-bandwidth product makes the circuit susceptible to parasitic capacitance, ground bounce, and supply-rail ringing. Use a solid ground plane, short input traces, and well-bypassed supply pins (typically 0.1 µF ceramic in parallel with 6.8 µF tantalum) to preserve the datasheet's distortion and noise performance in practice.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet alone.
کے لیے ڈراپ اِن متبادل OPA643P — یکساں پیکیج، پن سے پن مطابقت پذیر۔ مختلف پیکیج والے پرزے جن کے لیے PCB دوبارہ کام درکار ہو، شامل نہیں ہیں۔
اس سیریز میں مختلف ورژن
اسی سیریز کے ماڈلز جو ڈراپ اِن مطابقت رکھتے ہیں OPA643P (یکساں فارم فیکٹر اور فٹ پرنٹ) — میں مختلف Mounting Type, Slew Rate, Supply Voltage Range.
OPA642P
✅ ڈراپ-اِن ⚠️ تفصیلات غیر تصدیق شدہقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →OPA637P
✅ ڈراپ-اِن ⚠️ تفصیلات غیر تصدیق شدہ📋 حوالہ جاتی متبادل (کیٹلاگ میں نہیں)
OPA604P
✅ ڈراپ-اِن ⚠️ تفصیلات غیر تصدیق شدہ📋 حوالہ جاتی متبادل (کیٹلاگ میں نہیں)
NE5532P
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →LM358P
✅ ڈراپ-اِنقیمت کے لیے رابطہ کریں
ڈیٹا شیٹ دیکھیں →OPA643P زیادہ سے زیادہ ریٹنگز اور برقی خصوصیات
| Manufacturer | Texas Instruments (Burr-Brown) |
| Amplifier Type | Voltage Feedback |
| Number of Channels | 1 |
| Gain-Bandwidth Product (GBP) | 800 MHz |
| Slew Rate | 1000 V/µs |
| Input Voltage Noise Density | 2.3 nV/√Hz |
| Low Distortion (specified at) | 5 MHz |
| Stable for Closed-Loop Gains | ≥ 3 |
| Supply Voltage Range | ±5.5 V (max); ±5 V typical |
| آپریٹنگ درجہ حرارت رینج | -40 °C to +85 °C |
| پیکیج | 8-pin PDIP (P) |
| ماؤنٹنگ ٹائپ | Through-Hole |
| RoHS اسٹیٹس | Compliant (Pb-free variants available) |
| Datasheet Publication | 1998-04-27 (Burr-Brown original) |
OPA643P پن کنفیگریشن
| پن 1 | NC — No connection |
| پن 2 | IN- — Inverting input |
| پن 3 | IN+ — Non-inverting input |
| پن 4 | V- — Negative supply |
| پن 5 | NC — No connection |
| پن 6 | OUT — Amplifier output |
| پن 7 | V+ — Positive supply |
| پن 8 | NC — No connection |
عام استعمالات
OPA643P کے لیے موزوں ہے 6 ایپلیکیشنs: Wideband Instrumentation Front-End, High-Speed ADC Input Buffer, Video Line Driver / Buffer, Communications IF Amplifier, Transimpedance Amplifier for Photodiodes, Test and Measurement Front-End.
Wideband Instrumentation Front-End
The OPA643P's 800 MHz gain-bandwidth product and 1000 V/µs slew rate make it a strong choice as the first-stage amplifier in wideband instrumentation channels where signals of interest span from DC to tens of MHz. With 2.3 nV/√Hz input voltage noise, the amplifier preserves signal-to-noise ratio at low input levels. In a typical front-end it is configured as a non-inverting gain-of-2 to gain-of-5 stage, followed by an anti-alias filter and ADC. Trade-off: at high closed-loop gains the GBP rolls off linearly, so designs that need 100+ MHz of usable bandwidth must keep the gain low and cascade stages.
تجویز کردہ
High-Speed ADC Input Buffer
The OPA643P is well-suited as a buffer between sensor signal conditioning and a high-speed ADC. Its 1000 V/µs slew rate handles fast transient edges at 12-14 bit resolution, and its low 2.3 nV/√Hz noise floor supports SNR preservation. Place a 10-50 Ω series isolation resistor between the OPA643P output and the ADC input to damp sampling-glitch kickback. Unlike a discrete transistor buffer, the OPA643P adds negligible distortion (specified at 5 MHz) and maintains DC accuracy, which is critical for calibration. Trade-off: the device draws moderate quiescent current, so it is not ideal for always-on battery-powered channels.
تجویز کردہ
Video Line Driver / Buffer
The OPA643P's 800 MHz GBP easily covers standard-definition, enhanced-definition, and high-definition video bandwidths with substantial headroom. Its 1000 V/µs slew rate prevents edge-rate limiting of fast video transitions, and its low differential gain/phase error preserves color accuracy in composite video paths. The amp is commonly configured as a gain-of-2 driver capable of swinging 2 Vpp into 75 Ω back-terminated video loads. Trade-off: the 8-pin PDIP package is large for modern compact video modules - consider the SOIC-8 OPA643N variant for space-constrained designs.
تجویز کردہ
Communications IF Amplifier
In communications intermediate-frequency (IF) stages operating from 10 MHz to 100+ MHz, the OPA643P delivers the gain, bandwidth, and distortion performance required. Its 5 MHz low-distortion specification extends to usable performance at IF frequencies when operated at moderate closed-loop gain. The amplifier is often deployed in cellular base-station IF chains, software-defined radio (SDR) front-ends, and spectrum analyzer input stages. Trade-off: the 2.3 nV/√Hz noise floor is good but not class-leading for ultra-low-noise IF use; pair with a narrowband SAW or crystal filter ahead of the OPA643P for best selectivity.
تجویز کردہ
Transimpedance Amplifier for Photodiodes
The OPA643P's combination of 800 MHz GBP, 2.3 nV/√Hz input noise, and voltage-feedback topology makes it a viable transimpedance amplifier (TIA) for high-speed photodiodes in optical receivers, LIDAR front-ends, and medical imaging detectors. The voltage-feedback architecture yields low input bias current, which minimizes DC error in continuous-wave optical power measurements. Use a feedback resistor in the 1 kΩ to 100 kΩ range with a small feedback capacitor for stability. Trade-off: voltage-feedback TIAs have lower gain-bandwidth product at high transimpedance than current-feedback TIAs, so for very high gain (1 MΩ+) consider a dedicated current-feedback op amp.
تجویز کردہ
Test and Measurement Front-End
The OPA643P fits naturally into oscilloscope input buffers, spectrum analyzer front-ends, and arbitrary waveform generator output stages. Its 1000 V/µs slew rate and 800 MHz GBP preserve the integrity of fast arbitrary waveforms and high-frequency spectral content. In a 50 Ω output buffer, the OPA643P can deliver several mA of output current with low distortion. Trade-off: the PDIP-8 package has higher parasitic inductance than an SOIC-8, which may show up as ringing above 200 MHz; for highest-frequency test equipment the OPA643N (SOIC-8) is preferred.
تجویز کردہ
تجویز کردہ پروڈکٹس کا خلاصہ
کے لیے انجینئرنگ ریفرنس ڈیٹا OPA643P — موازنہ، ڈیزائن رہنمائی، اور تعمیل کی معلومات۔
انتخاب کی گائیڈ
متبادلات کے ساتھ موازنہ
| پیرامیٹر | یہ پروڈکٹ | OPA642P | OPA637P | NE5532P | LM358P |
|---|---|---|---|---|---|
| Package | 8-pin PDIP (P) | 8-pin PDIP (P) - same | 8-pin PDIP (P) - same | 8-pin PDIP (P) - same | 8-pin PDIP (P) - same |
| Brand | Texas Instruments (Burr-Brown) | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Gain-Bandwidth Product | 800 MHz | ~200 MHz | ~80 MHz | ~10 MHz | ~1 MHz |
| Slew Rate | 1000 V/µs | ~250 V/µs | ~100 V/µs | ~9 V/µs | ~0.3 V/µs |
| Input Voltage Noise | 2.3 nV/√Hz | ~3.5 nV/√Hz | ~4.5 nV/√Hz | ~5 nV/√Hz | ~40 nV/√Hz |
| Topology | Voltage Feedback | Voltage Feedback | Voltage Feedback | Voltage Feedback | Voltage Feedback |
| Channels | 1 (Single) | 1 (Single) | 1 (Single) | 2 (Dual) | 2 (Dual) |
| Supply Voltage (max) | ±5.5 V | ±5.5 V | ±15 V | ±15 V | +32 V single-supply |
اہم امتیازی خصوصیات
- Highest GBP and slew rate in the listed same-package alternatives (بمقابلہOPA642P)
- True single-channel wideband vs dual-channel general-purpose (بمقابلہNE5532P)
- Through-hole PDIP package for legacy and prototype builds (بمقابلہOPA643N (SOIC-8))
ڈیزائن نوٹس
At 800 MHz GBP, the OPA643P is highly sensitive to parasitic capacitance on the inverting input node. Keep the inverting-input trace to the feedback network as short as possible, and use a ground plane on the layer directly beneath the op amp. Place the feedback resistor (Rf) within 5 mm of the inverting-input pin to minimize stray capacitance, which otherwise reduces phase margin and can cause peaking or oscillation. Estimated: stray capacitance of 1 pF at 800 MHz contributes approximately 25 Ω of impedance, which is significant relative to typical Rf values of 1-5 kΩ.
Bypass the supply pins with a 0.1 µF ceramic capacitor placed within 3 mm of each supply pin, in parallel with a 6.8 µF to 10 µF tantalum or low-ESR electrolytic capacitor. Star-ground the analog ground to the op-amp load ground to prevent ground-loop noise from coupling into the signal path. For dual-supply operation, ensure that the V+ and V- rails come up simultaneously to avoid reverse-biasing the input stage during power sequencing.
The OPA643P's 1000 V/µs slew rate demands a wideband output connection. Use a 50 Ω characteristic-impedance trace for output runs longer than approximately 10 mm, and terminate appropriately to avoid reflections. For ADC-driver applications, place a 10-50 Ω series resistor between the OPA643P output and the ADC input pin; this resistor isolates the capacitive ADC input from the op-amp output and prevents the sampling glitch from feeding back into the amplifier's output stage.
Do not operate the OPA643P at closed-loop gains below 3 - it is not unity-gain stable and may oscillate at lower gains. Do not exceed the ±5.5 V maximum supply; the absolute-maximum rating is 11 V total across V+ and V-. Do not use the OPA643P in low-gain precision-instrumentation paths where DC accuracy is paramount - consider the precision-optimized OPA627 or OPA637 family instead. Estimated: with ±5.5 V supplies, maximum output swing is approximately ±4.5 V into 1 kΩ load.
تعمیل کی معلومات
RoHS-compliant Pb-free variants of the OPA643P are available. Original 1998 Burr-Brown datasheet pre-dates RoHS; the current TI datasheet and product page reflect RoHS/REACH compliance. Not AEC-Q100 qualified - the OPA643P is intended for industrial, instrumentation, communications, and test & measurement, not automotive.