My Inquiry
My Account
Texas Instruments OPA2381AIDGKR
- Part No.:
- OPA2381AIDGKR
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
OPA2381AIDGKR.pdf
- Description:
- IC TRANSIMPEDANCE 2 CIRC 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,311
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
OPA2381AIDGKR 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, 10nV/√Hz input voltage noise, and >250kHz transimpedance bandwidth in typical configurations-enabling high-accuracy optical signal conditioning in single-supply systems.
For engineers reviewing the OPA2381AIDGKR datasheet, OPA2381AIDGKR pinout, OPA2381AIDGKR application, or OPA2381AIDGKR equivalent, key selection considerations include its dual-channel MSOP-8 package, −40°C to +125°C operation, fast 200ns overload recovery, extended 0V output swing capability with pulldown resistor, and suitability for low-current, wide-dynamic-range I/V conversion in medical and industrial sensing.
Technical Context
The OPA2381 integrates an auto-zero core with a high-speed 18MHz amplifier to achieve ultra-low drift (0.1µV/°C max) and near-zero 1/f noise while maintaining wide bandwidth. Its architecture enables stable transimpedance operation despite photodiode capacitance up to 100pF, with feedback compensation supported by internal input capacitance (1pF differential, 2.5pF common-mode).
It operates from 2.7V to 5.5V, supports rail-to-rail output swing to 0V via external pulldown resistor to −5V, and features ESD-hardened inputs (1500V HBM). The dual-channel configuration shares no internal coupling-channel separation exceeds 100dB at 1kHz-making it suitable for independent, matched analog front-ends.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain Bandwidth | 18MHz - enables >250kHz transimpedance bandwidth with typical photodiode capacitance and feedback resistors up to 10MΩ. |
| Input Bias Current | 3pA (max) - minimizes dark-current error in photodiode monitoring, critical for sub-nA signal fidelity. |
| Offset Voltage | 25µV (max) - ensures ≤0.25% full-scale error in 10mV-output I/V stages without trimming. |
| Offset Drift | 0.1µV/°C (max) - guarantees <1µV total drift over −40°C to +125°C, supporting uncalibrated long-life instrumentation. |
| Input Voltage Noise | 10nV/√Hz (f > 1MHz) - maintains SNR integrity in high-frequency optical detection where photodiode capacitance elevates noise gain. |
| Quiescent Current | 800µA per channel - allows dual-channel precision amplification within 1.6mA total supply budget for battery-powered portable analyzers. |
| Supply Range | 2.7V to 5.5V - compatible with single Li-ion, USB, or industrial 3.3V/5V rails without level-shifting. |
Pinout & Package
OPA2381AIDGKR is housed in an MSOP-8 (DGK) package with exposed thermal pad, rated for −40°C to +125°C operation. Pin 1 is NC (no internal connection); pins 2–5 and 7–8 form two independent op-amp channels plus power terminals.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | No Connect | Internally unconnected; must be left floating or tied to ground for mechanical stability-no electrical function. |
| 2 | V+ | Positive supply rail for both amplifiers; requires local 1µF ceramic bypass to minimize PSRR degradation at high frequency. |
| 3 | Out A | Output of Channel A; capable of swinging within 50mV of V− and 600mV of V+ (10kΩ load), extendable to 0V with pulldown resistor. |
| 4 | −In A | Inverting input of Channel A; summing node for photodiode anode or transimpedance feedback network. |
| 5 | +In A | Non-inverting input of Channel A; used as fixed bias reference (e.g., 0.5V) to set dark-output baseline and reverse-bias photodiode. |
| 6 | +In B | Non-inverting input of Channel B; electrically isolated from Channel A-supports independent biasing for dual-sensor systems. |
| 7 | −In B | Inverting input of Channel B; dedicated summing node for second photodiode or current source. |
| 8 | V− | Negative supply rail (typically ground); shared return path for both amplifiers and pulldown resistor networks. |
Key Features
| Feature | Design Value |
|---|---|
| Auto-zero architecture | Continuous 10kHz zero-correction eliminates 1/f noise and drift without introducing switching artifacts above 20MHz. |
| Fast overload recovery | 200ns return to linear operation after positive-rail saturation-critical for burst-mode optical receivers and pulse-width-modulated light sources. |
| Extended output swing | 0V output achievable using external 10kΩ pulldown resistor to −5V, enabling true single-supply 0–4.096V interfacing with 16-bit ADCs. |
| High channel separation | >100dB at 1kHz-prevents crosstalk between dual photodiode channels in multi-axis optical encoders or differential absorption sensors. |
| Low input capacitance | 1pF differential + 2.5pF common-mode-minimizes noise gain peaking and stabilizes transimpedance loops with high-C photodiodes. |
Applications
| Photodiode Monitoring | Optical Amplifier Front-End |
|---|---|
Use Scenario: Real-time monitoring of low-light-level photodiode current in fiber-optic power meters and laser safety interlocks. IC Role / Device Role / Timing Role: Dual-channel transimpedance amplifier converting 10nA–1mA photocurrent into 0–4V linear voltage output with matched gain and offset. Use Value: 5-decade dynamic range enables single-stage measurement without range-switching, reducing system latency and component count. |
Use Scenario: Signal conditioning in EDFA (Erbium-Doped Fiber Amplifier) monitor ports for forward/backward pump power control. IC Role / Device Role / Timing Role: Precision I/V converter feeding analog control loop for automatic gain control (AGC) circuitry. Use Value: 0.1µV/°C drift ensures stable gain calibration over equipment lifetime without field recalibration. |
| CAT-Scanner Detector Array | Photo Lab Densitometer |
Use Scenario: Multi-channel X-ray scintillation signal readout in computed tomography detector modules. IC Role / Device Role / Timing Role: Dual-channel low-noise amplifier per detector element, driving multiplexed 16-bit ADCs with minimal added noise. Use Value: 10nV/√Hz noise density preserves SNR in low-flux imaging, directly improving contrast resolution in reconstructed slices. |
Use Scenario: High-precision optical density measurement of photographic film using calibrated LED illumination and silicon photodiodes. IC Role / Device Role / Timing Role: Transimpedance stage converting transmitted light current into stable DC voltage for ratiometric densitometry. Use Value: 25µV max offset ensures <0.01 OD accuracy across 0–4.0 density range without software correction. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transimpedance amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| OPA2380AIDGKR | 90MHz GBW, 2.7V–5.5V supply, but higher 50pA bias current and no auto-zero-higher drift (1µV/°C). | Better suited for high-speed, lower-precision photodiode amps where bandwidth dominates over dc accuracy. | Select when transimpedance bandwidth >1MHz is required and drift tolerance >1µV/°C is acceptable. |
| OPA2189IDGKR | Zero-drift, 2.2MHz GBW, 0.2µV/°C drift, 0.4pA bias current-but limited to 2.7V–36V supply and larger SOIC-8 package. | Preferred for high-voltage, ultra-low-drift applications like industrial process analyzers, not compact optical modules. | Choose for ultra-stable dc performance in non-speed-critical, wide-supply systems where MSOP-8 footprint is not mandatory. |
Compared with OPA2381AIDGKR, OPA2380AIDGKR trades dc precision for speed, while OPA2189IDGKR sacrifices bandwidth and package size for superior drift and bias current-making OPA2381AIDGKR the optimal balance for compact, dual-channel, wide-dynamic-range optical sensing.
Availability
OPA2381AIDGKR is available at Aetrix Electronics and suitable for photodiode monitoring, CAT-scanner detector arrays, and photo lab densitometers requiring stable component supply across automotive, medical, and industrial temperature ranges.
Supply support for OPA2381AIDGKR 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 solutions.
The OPA2381 belongs to TI's precision transimpedance amplifier product line, engineered specifically for low-current optical sensing applications demanding wide dynamic range, low drift, and single-supply operability in space-constrained designs.
FAQ
What is the maximum photodiode capacitance supported by OPA2381AIDGKR in a stable transimpedance configuration?
OPA2381AIDGKR supports stable transimpedance operation with photodiode capacitances up to 100pF when paired with appropriate feedback compensation (e.g., CF = 0.5–4pF depending on RF). Its 1pF differential + 2.5pF common-mode input capacitance and 18MHz GBW enable >250kHz bandwidth even with 50–100pF diodes, as verified in TI's SBOS313B Figure 6 and 7.
Can OPA2381AIDGKR achieve true 0V output swing on a single +5V supply?
Yes-OPA2381AIDGKR achieves 0V output swing on a +5V supply when a 10kΩ pulldown resistor connects the output to −5V, as documented in Figure 3 and Section "Achieving Output Swing to Ground" of the SBOS313B datasheet. This extends the linear output range to 0–4.4V, enabling direct interface with 16-bit ADCs like ADS8325.
How does the auto-zero architecture of OPA2381AIDGKR affect its noise performance at 10kHz?
OPA2381AIDGKR's auto-zero correction occurs at 10kHz, but internal filtering suppresses fundamental noise energy at that frequency. Measured input voltage noise remains flat at 10nV/√Hz above 1MHz, and residual glitches appear only >20MHz-well beyond typical transimpedance bandwidths-so no additional filtering is needed for most optical sensing applications.
Is OPA2381AIDGKR pin-compatible with OPA2381AIDRBR (DFN-8 package)?
No-OPA2381AIDGKR (MSOP-8) and OPA2381AIDRBR (DFN-8) share identical electrical specifications and operating conditions but have different pinouts and footprints. MSOP-8 uses pins 1–8 in standard order with NC at pin 1; DFN-8 places V+ at pin 2 and has no NC pin. PCB layout changes are required for substitution.
What is the recommended bypass capacitor for OPA2381AIDGKR power pins?
Texas Instruments specifies a 1µF ceramic or tantalum capacitor placed as close as possible to the V+ (pin 2) and V− (pin 8) pins of OPA2381AIDGKR, as stated in Section "Basic Operation" of SBOS313B. Electrolytic capacitors are explicitly discouraged due to higher ESR and inductance, which degrade high-frequency PSRR and stability.
OPA2381AIDGKR 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
OPA2381AIDGKR FAQ
1.How can I place an order for OPA2381AIDGKR through Aetrix?
Please submit a Request for Quotation (RFQ) for OPA2381AIDGKR 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 OPA2381AIDGKR reliable?
The price and inventory of OPA2381AIDGKR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for OPA2381AIDGKR is usually 5 days.
3.What payment methods are accepted for OPA2381AIDGKR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for OPA2381AIDGKR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for OPA2381AIDGKR?
OPA2381AIDGKR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your OPA2381AIDGKR 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 OPA2381AIDGKR?
For technical support, including OPA2381AIDGKR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your OPA2381AIDGKR requirements.
6.How does Aetrix verify that OPA2381AIDGKR is sourced from the original manufacturer or authorized distributors?
All OPA2381AIDGKR 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 OPA2381AIDGKR meets industry standards.
7.What is the process for return or replacement of OPA2381AIDGKR?
All OPA2381AIDGKR units undergo pre-shipment inspection (PSI). If there is an issue with OPA2381AIDGKR, 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 OPA2381AIDGKR part is unused and in its original packaging.
Return procedure for OPA2381AIDGKR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
OPA2381AIDGKR Tags
-
LM358DT
STMicroelectronics
-
LM358DR
Texas Instruments
-
LM2904DR
Texas Instruments
-
LM358ADR
Texas Instruments
-
LM2904DGKR
Texas Instruments
-
LM324DR
Texas Instruments
-
MCP6006T-E/OT
Microchip Technology
-
MCP6006UT-E/OT
Microchip Technology
-
LM324PWR
Texas Instruments
-
LM2902PWR
Texas Instruments
-
LM2902DR
Texas Instruments
-
LM358P
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
