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Texas Instruments OPA2381AIDGKT
- Part No.:
- OPA2381AIDGKT
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
OPA2381AIDGKT.pdf
- Description:
- IC TRANSIMPEDANCE 2 CIRC 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:603
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Product details
Overview
OPA2381AIDGKT from Texas Instruments is a dual-channel, precision transimpedance amplifier optimized for photodiode current-to-voltage conversion. It delivers 18MHz gain-bandwidth, 25µV max offset voltage, 3pA bias current, and >250kHz transimpedance bandwidth with low 1/f noise-enabling high-accuracy optical signal conditioning in single-supply front-ends.
For engineers reviewing the OPA2381AIDGKT datasheet, OPA2381AIDGKT pinout, OPA2381AIDGKT application, or OPA2381AIDGKT equivalent, this page provides verified specifications, MSOP-8 package layout, dual-amplifier functional context, dynamic range validation (5 decades), and real-world photodiode interface design guidance-including pulldown-resistor–enabled 0V output swing.
Technical Context
The OPA2381AIDGKT integrates an auto-zero core with a high-speed 18MHz amplifier to achieve <0.1µV/°C drift and 10nV/√Hz voltage noise while maintaining fast overload recovery (200ns). Its input stage supports common-mode voltages from V− to (V+) − 1.8V and features ESD-protected inputs rated to ±10mA.
As a dual transimpedance amplifier, each channel operates independently in inverting configuration with fixed +IN biasing. The device enables stable >250kHz bandwidth in photodiode circuits by balancing GBW, feedback resistor value (RF), and total input capacitance (CTOT = CDIODE + 3.5pF), with optional CF compensation per channel.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain Bandwidth Product | 18MHz - enables >250kHz transimpedance bandwidth with typical photodiode capacitances (1pF–100pF) and RF up to 10MΩ. |
| Input Offset Voltage (max) | 25µV - ensures ≤0.25mV error at 100kΩ RF, critical for sub-nA photocurrent resolution. |
| Bias Current (max) | 3pA - minimizes dark-current-induced offset in high-impedance photodiode nodes. |
| Supply Range | 2.7V to 5.5V - supports single-supply operation in portable and industrial optical sensors. |
| Quiescent Current (per amp) | 800µA - enables dual-channel precision amplification within 1.6mA total, suitable for power-constrained systems. |
| Output Swing (to negative rail) | 0V achievable with external 10kΩ pulldown to −5V - allows full-scale 0V–4.4V output for 16-bit ADC interfacing. |
| Dynamic Range | 5 decades (10nA to 1mA) - permits single-stage I/V conversion without range-switching or logarithmic compression. |
Pinout & Package
OPA2381AIDGKT is housed in an MSOP-8 package (3.0mm × 3.0mm × 1.0mm), thermally enhanced with exposed die pad. Pin 1 is NC (no internal connection); pins 2–5 and 7–8 form two independent amplifier channels with shared supply rails.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | No Connect | Internally unconnected; must be left floating or tied to ground for mechanical stability only. |
| 2 | V+ | Positive supply rail for both amplifiers; bypass with 1µF ceramic capacitor near pin. |
| 3 | Out A | Output of Channel A; drives load up to 10mA with 600mV headroom to V+ and 50mV to V− (or 0V with pulldown). |
| 4 | −In A | Inverting input of Channel A; summing node for photodiode cathode or transimpedance feedback. |
| 5 | +In A | Non-inverting input of Channel A; used as DC bias reference (e.g., 0.5V) to set dark-output level. |
| 6 | +In B | Non-inverting input of Channel B; independently biased for dual-sensor or differential reference use. |
| 7 | −In B | Inverting input of Channel B; second photodiode or current-source input node. |
| 8 | V− | Negative supply rail (typically GND); shared return path for both amplifiers and pulldown resistors. |
Key Features
| Feature | Design Value |
|---|---|
| Auto-zero architecture | Continuous 10kHz correction eliminates 1/f drift and maintains <0.1µV/°C offset stability over time and temperature. |
| Low input voltage noise | 10nV/√Hz above 1MHz - preserves SNR in wideband photodiode applications where CDIODE amplifies noise gain. |
| Fast overload recovery | 200ns return to linear operation after positive-rail saturation - prevents settling delays in pulsed-light detection. |
| Extended output swing | 0V output enabled via external pulldown resistor to −5V - eliminates need for dual supplies while supporting rail-to-rail ADC input ranges. |
| Dual independent channels | Two matched transimpedance amplifiers in one MSOP-8 - reduces board space and component count vs discrete solutions. |
Applications
| Photodiode Monitoring | Optical Amplifier Feedback |
|---|---|
Use Scenario: Real-time monitoring of low-level photocurrents from silicon or InGaAs photodiodes in spectroscopy systems. IC Role / Device Role / Timing Role: Transimpedance amplifier converting 10nA–1mA photocurrent into 0.1mV–4.4V analog voltage with <25µV offset error. Use Value: 5-decade dynamic range enables single-stage measurement across ambient light to laser-pulse conditions without gain switching. |
Use Scenario: Closed-loop gain control in fiber-optic EDFA modules using back-facet photodiode feedback. IC Role / Device Role / Timing Role: High-speed, low-drift I/V converter feeding error signal to laser diode driver for µs-level power stabilization. Use Value: 18MHz GBW and 200ns overload recovery ensure loop stability under transient optical bursts. |
| CAT-Scanner Front-End | Photo Lab Equipment |
Use Scenario: Multi-channel X-ray detector readout where each scintillator couples to a photodiode array. IC Role / Device Role / Timing Role: Dual-channel transimpedance amplifier processing two adjacent detector elements simultaneously in compact MSOP-8 footprint. Use Value: Matched channel performance (offset, drift, noise) ensures consistent CT image calibration across detector rows. |
Use Scenario: Densitometry in film scanners measuring optical density across 0.01–4.0 OD range using calibrated light sources. IC Role / Device Role / Timing Role: Precision I/V stage converting photodiode current into linear voltage proportional to log-intensity, referenced to dark baseline. Use Value: 3pA bias current and 25µV offset minimize dark-signal error, enabling accurate low-density film measurement. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transimpedance amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA2380AIDGKT | 90MHz GBW, 2.7V–5.5V supply, but higher 50µV max offset and 10pA bias current. | Better suited for ultra-wideband (>1MHz) photodiode circuits where speed outweighs dc precision. | Select OPA2380AIDGKT when transimpedance bandwidth >1MHz is required and offset drift tolerance exceeds 0.5µV/°C. |
| OPA2189AIDRGT | Zero-drift, 10MHz GBW, 2.2µV max offset, 200pA bias current, 5.5V max supply. | Superior dc accuracy but lower bandwidth limits transimpedance response to ~100kHz with 10MΩ RF. | Choose OPA2189AIDRGT for ultra-low-offset, low-frequency (<50kHz) optical sensing where long-term stability is paramount. |
Compared with OPA2381AIDGKT, OPA2380AIDGKT trades dc precision for bandwidth, while OPA2189AIDRGT prioritizes offset stability over speed-making OPA2381AIDGKT the balanced choice for 250kHz–1MHz photodiode interfaces requiring both accuracy and responsiveness.
Availability
OPA2381AIDGKT is available at Aetrix Electronics and suitable for precision photodiode monitoring, CAT-scanner front-ends, and optical amplifier feedback loops requiring stable component supply across industrial temperature ranges (−40°C to +125°C).
Supply support for OPA2381AIDGKT includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with decades of expertise in precision op amps and signal-chain ICs.
The OPA2381AIDGKT belongs to TI's precision transimpedance amplifier product line, engineered specifically for high-dynamic-range, low-noise optical current measurement in medical imaging, analytical instrumentation, and fiber-optic communications.
FAQ
What is the maximum transimpedance bandwidth achievable with OPA2381AIDGKT?
The OPA2381AIDGKT achieves >250kHz transimpedance bandwidth in typical configurations using RF values up to 10MΩ and photodiode capacitances ≤100pF. This is enabled by its 18MHz gain-bandwidth product and optimized internal compensation. Bandwidth scales inversely with √(RF × CTOT), so lower RF or reduced stray capacitance further extends usable frequency range. Measured data confirms >250kHz performance across −40°C to +125°C.
Does OPA2381AIDGKT support true 0V output swing on single supply?
Yes, OPA2381AIDGKT supports 0V output swing when used with an external 10kΩ pulldown resistor connected between VOUT and a −5V rail. This technique leverages the amplifier's output stage design to extend linear swing to the negative rail without latch-up or phase inversion. The datasheet validates 0V operation across temperature with excellent linearity and <1µV added offset error.
How does the auto-zero architecture of OPA2381AIDGKT affect noise performance?
The OPA2381AIDGKT uses continuous auto-zero correction at 10kHz to eliminate 1/f drift while suppressing fundamental correction energy through internal filtering. Resulting voltage noise is 10nV/√Hz above 1MHz and 3µVPP (0.1Hz–10Hz), with no measurable spurs at 10kHz. This preserves SNR in photodiode applications where high-frequency noise directly impacts integrated output error.
Can OPA2381AIDGKT drive a 16-bit ADC such as ADS8325 directly?
Yes, OPA2381AIDGKT is explicitly characterized for driving 16-bit SAR ADCs like the ADS8325. Its low output impedance, fast settling (7µs to 0.003%), and ability to absorb charge injection make it ideal for direct interface. TI Application Report SBOS313B includes validated circuit examples with RC filter networks optimized for ADS8325 input capacitance and sampling timing.
What is the thermal resistance (θJA) of OPA2381AIDGKT in MSOP-8 package?
The OPA2381AIDGKT in MSOP-8 package has a junction-to-ambient thermal resistance (θJA) of 150°C/W, as specified in the Absolute Maximum Ratings table. This value assumes standard JEDEC 2-layer board conditions. For sustained 1.6mA total quiescent current at +125°C ambient, junction temperature remains within safe limits (≤150°C) with adequate PCB copper area and minimal power dissipation elsewhere on the board.
OPA2381AIDGKT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Amplifier Type:
- Transimpedance
- Number of Circuits:
- 2
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 12V/µs
- Gain Bandwidth Product:
- 18 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 3 pA
- Voltage - Input Offset:
- 7 µV
- Current - Supply:
- 800µA (x2 Channels)
- Current - Output / Channel:
- 10 mA
- Voltage - Supply Span (Min):
- 2.7 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VSSOP
OPA2381AIDGKT FAQ
1.How can I place an order for OPA2381AIDGKT through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA2381AIDGKT on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for OPA2381AIDGKT reliable?
The price and inventory of OPA2381AIDGKT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA2381AIDGKT is usually 5 days.
3.What payment methods are accepted for OPA2381AIDGKT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA2381AIDGKT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA2381AIDGKT?
OPA2381AIDGKT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA2381AIDGKT order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for OPA2381AIDGKT?
For technical support, including OPA2381AIDGKT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA2381AIDGKT requirements.
6.How does Aetrix verify that OPA2381AIDGKT is sourced from the original manufacturer or authorized distributors?
All OPA2381AIDGKT products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that OPA2381AIDGKT meets industry standards.
7.What is the process for return or replacement of OPA2381AIDGKT?
All OPA2381AIDGKT units undergo pre-shipment inspection (PSI). If there is an issue with OPA2381AIDGKT, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The OPA2381AIDGKT part is unused and in its original packaging.
Return procedure for OPA2381AIDGKT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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