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Texas Instruments INA103KU
- Part No.:
- INA103KU
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 16-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
INA103KU.pdf
- Description:
- IC INST AMP 1 CIRCUIT 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:415
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Product details
Overview
INA103KU from Texas Instruments (formerly Burr-Brown) is a low-noise, low-distortion current-feedback instrumentation amplifier optimized for high-fidelity audio and precision sensor signal conditioning. It delivers 1 nV/√Hz input voltage noise at 1 kHz, 0.0009% THD+N at G = 100, and 800 kHz –3 dB bandwidth at G = 100, enabling high-resolution amplification of microphone, thermocouple, and strain gage outputs in professional audio and industrial measurement systems.
For engineers reviewing the INA103KU datasheet, INA103KU pinout, INA103KU application, or INA103KU equivalent, this page provides verified technical context, validated pin functions, real-world application mappings, and two confirmed alternative parts with documented functional trade-offs for sensor interface and low-noise preamplifier designs.
Technical Context
The INA103KU employs a three-op-amp current-feedback architecture with laser-trimmed 3 kΩ internal feedback resistors, enabling precise gain setting (G = 1 or 100 via pin-strapping, or programmable via external RG). Its balanced differential inputs and copper lead frame in SOIC-16 package support stable operation up to ±25 V supplies and deliver >100 dB CMRR at DC–60 Hz when G = 100.
Distortion cancellation circuitry suppresses harmonic and intermodulation distortion, achieving 0.0009% THD+N at 1 kHz and G = 100. Input bias current is 2.5 µA typical, limiting optimal use to source impedances ≤10 kΩ; for higher-impedance sensors, the FET-input INA111 is recommended per datasheet guidance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Noise | 1 nV/√Hz at 1 kHz - enables near-theoretical noise floor with 200 Ω sources, critical for microphone preamps. |
| THD + Noise | 0.0009% at 1 kHz, G = 100 - supports ultra-low-distortion audio signal chains without transformer coupling. |
| –3 dB Bandwidth | 800 kHz at G = 100 - allows accurate amplification of fast transients in bridge-based sensor outputs. |
| CMRR | >100 dB at DC–60 Hz, G = 100 - rejects common-mode interference in noisy industrial environments. |
| Supply Range | ±9 V to ±25 V - accommodates wide dynamic range output swing (±21 V into 600 Ω at ±25 V). |
| Gain Accuracy | 0.07% max error at G = 100 - ensures calibrated measurement fidelity in weigh-scale and transducer applications. |
| Input Impedance | 60 MΩ || 5 pF common-mode - preserves signal integrity with high-Z sources like piezoelectric sensors. |
Pinout & Package
SOL-16 surface-mount package (SOIC-DW, 7.5 mm × 10.3 mm, 1.27 mm pitch, max height 2.65 mm), RoHS-compliant, moisture sensitivity level 3 (260 °C peak reflow, 168 hr floor life).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 16 | +Input / –Input | Differential input terminals; high-impedance, balanced nodes requiring symmetrical layout to preserve CMRR. |
| 2, 15 | +Gain Sense / –Gain Sense | Internal 3 kΩ resistor taps; shorting pin 14 to 6 sets G = 100; leaving pin 14 open sets G = 1. |
| 3, 4 | +Offset Null / –Offset Null | Laser-trimmed offset adjustment points; optional external potentiometer (10 kΩ) enables <±250 mV output offset trim. |
| 5, 6 | +Gain Drive / –R | Internal gain-setting node pair; pin 6 connects to pin 14 for G = 100; external RG between pins 2 and 15 enables custom gain. |
| 7 | Ref | Output reference terminal; must be low-impedance connection to maintain CMRR; used for output offset injection. |
| 8 | V– | Negative supply rail; bypass with 1 µF tantalum capacitor near pin for stability. |
| 9 | V+ | Positive supply rail; bypass with 1 µF tantalum capacitor near pin for stability. |
| 10, 11 | Sense / Output | Output sense terminal (pin 11) enables remote sensing to compensate for I·R drop in heavy-load applications. |
| 12, 13, 14 | +R / –Gain Drive / G | Internal feedback network nodes; pin 14 is gain-select control; pin 12 connects to internal 6 kΩ resistor for G equation. |
| 15 | +Gain Sense | See pin 2; dual-sense configuration improves gain accuracy and thermal tracking. |
Key Features
| Feature | Design Value |
|---|---|
| Current-feedback topology | Enables 800 kHz bandwidth at G = 100 and 15 V/µs slew rate - supports fast settling (<1.5 µs, 0.1%) in dynamic sensor readouts. |
| Laser-trimmed 3 kΩ resistors | Provides 0.07% gain error at G = 100 and 25 ppm/°C tempco - eliminates need for external precision resistors in fixed-gain configurations. |
| Built-in G = 1 and G = 100 modes | Reduces BOM count and layout complexity; pin-strapped operation avoids external RG placement errors affecting noise and stability. |
| Output sense (pin 11) | Allows closed-loop compensation of PCB trace resistance, maintaining gain accuracy when driving 600 Ω loads or long cables. |
| Copper lead frame | Delivers θJA = 100 °C/W in SOIC package - sustains 40 mA output current without thermal derating in compact audio stage layouts. |
Applications
| High-Quality Microphone Preamplifier | Moving-Coil Preamplifier |
|---|---|
Use Scenario: Professional audio console input stage amplifying balanced low-impedance condenser microphones with phantom power. IC Role / Device Role / Timing Role: Primary low-noise, low-distortion instrumentation amplifier providing G = 100 with 1 nV/√Hz noise floor and 0.0009% THD+N. Use Value: Replaces bulky, lossy input transformers while delivering superior SNR and transient response in studio-grade recording paths. | Use Scenario: Phono preamplifier stage for magnetic cartridge signals requiring RIAA equalization and high gain. IC Role / Device Role / Timing Role: First-stage gain block with G = 100, leveraging wide bandwidth (800 kHz) to preserve high-frequency detail before EQ filtering. Use Value: Minimizes added noise and distortion in low-level moving-coil signals, enabling clean RIAA playback without transformer saturation artifacts. |
| Differential Receiver for Bridge Sensors | Strain Gage Amplifier in Weigh-Scale Systems |
Use Scenario: Industrial PLC analog input module receiving differential signals from load cells or pressure transducers over twisted-pair wiring. IC Role / Device Role / Timing Role: Precision instrumentation amplifier rejecting common-mode noise (100+ dB CMRR) and amplifying mV-level bridge outputs. Use Value: Maintains measurement linearity (0.0006% nonlinearity) and stability across temperature (25 ppm/°C gain drift) in harsh factory environments. | Use Scenario: On-board signal conditioner in commercial weighing scales using full-bridge strain gages with 2–3 mV/V sensitivity. IC Role / Device Role / Timing Role: Fixed-G = 100 amplifier with output sense (pin 11) compensating for PCB trace resistance in 4-wire Kelvin connections. Use Value: Ensures calibrated weight accuracy by eliminating gain error from trace IR drop and sustaining >100 dB CMRR against EMI in AC-powered enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar instrumentation amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA114BP | Lower input bias current (500 pA vs 2.5 µA), higher CMRR (120 dB), but lower bandwidth (1 MHz at G = 1) and higher noise (8 nV/√Hz). | Better for high-impedance DC-coupled sensors (e.g., pH electrodes); unsuitable for audio-band low-noise preamps. | Select INA114BP when input Z > 100 kΩ and DC precision outweighs audio bandwidth needs. |
| INA111BU | FET-input architecture, 10 pA bias current, 12 MHz GBW, but higher voltage noise (12 nV/√Hz) and no built-in G = 100 option. | Optimized for high-speed, high-Z AC-coupled sensors (e.g., piezoelectric accelerometers); requires external gain resistors. | Choose INA111BU for >1 MHz small-signal bandwidth with high-Z sources, accepting higher noise than INA103KU. |
Compared with INA114BP and INA111BU, the INA103KU uniquely balances ultra-low noise (1 nV/√Hz), high bandwidth (800 kHz at G = 100), and factory-set gain modes-making it the only option among the three qualified for professional microphone preamplification without external gain components.
Availability
INA103KU is available at Aetrix Electronics and suitable for professional audio equipment, industrial weigh-scale systems, bridge transducer interfaces, and high-fidelity sensor signal conditioning requiring stable component supply and long-term lifecycle continuity.
Supply support for INA103KU 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 acquired Burr-Brown in 2000 and maintains its precision analog portfolio, emphasizing high-performance signal chain ICs for industrial, audio, and test/measurement markets.
The INA103KU belongs to TI's legacy instrumentation amplifier family designed specifically for low-noise, low-distortion amplification of weak differential signals from microphones, thermocouples, and strain gages in both commercial and industrial settings.
FAQ
What is the maximum supply voltage for the INA103KU?
The INA103KU supports a rated supply voltage of ±15 V with an absolute maximum range of ±25 V. Operation at ±25 V enables ±21 V output swing into 600 Ω, making it suitable for high-level audio stages. Exceeding ±25 V risks permanent damage per absolute maximum ratings. The INA103KU datasheet specifies performance parameters at ±15 V, but all electrical characteristics remain valid across the full ±9 V to ±25 V range.
Does the INA103KU require external resistors to achieve G = 100?
No, the INA103KU does not require external resistors to achieve G = 100. It features built-in laser-trimmed 3 kΩ feedback resistors; connecting pin 14 to pin 6 configures the device for G = 100. External RG resistors are only needed for gains other than 1 or 100, per the equation G = 1 + 6 kΩ/RG. This internal configuration reduces layout sensitivity and preserves the 0.07% gain accuracy specified for the INA103KU at G = 100.
Can the INA103KU drive a 600 Ω load effectively?
Yes, the INA103KU can drive a 600 Ω load effectively, delivering ±12 V output swing at TA = TMIN to TMAX and ±21 V at ±25 V supply with TA = 25°C. Its ±40 mA output current capability and output sense pin (pin 11) allow remote sensing to compensate for I·R losses in PCB traces or cables. For sustained full-power operation into 600 Ω, ensure proper thermal management: the SOIC package has θJA = 100 °C/W, so power dissipation must stay within safe junction temperature limits.
How does the INA103KU compare to the AD625 it upgrades?
The INA103KU upgrades the AD625 with significantly lower noise (1 nV/√Hz vs ~5 nV/√Hz), lower distortion (0.0009% THD+N vs ~0.002%), higher bandwidth (800 kHz at G = 100 vs ~200 kHz), and improved overload recovery (1 µs vs >10 µs). Unlike the AD625, the INA103KU includes internal gain-setting resistors for G = 1 and G = 100, eliminating external resistor matching requirements. These improvements make the INA103KU suitable for demanding audio and precision measurement applications where the AD625 falls short.
Is the INA103KU suitable for thermocouple amplification?
Yes, the INA103KU is suitable for thermocouple amplification due to its low input offset voltage (250 + 5000/G µV for KU grade), high CMRR (>100 dB at G = 100), and low 1/f noise - all critical for resolving µV-level thermocouple outputs amid millivolt-level common-mode interference. Its wide supply range (±9 V to ±25 V) supports cold-junction compensation circuitry, and the output sense pin enables accurate gain calibration. However, for high-impedance thermocouples (>10 kΩ), the INA114BP is preferred due to its 500 pA input bias current.
INA103KU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Amplifier Type:
- Instrumentation
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 15V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 6 MHz
- Current - Input Bias:
- 2.5 µA
- Voltage - Input Offset:
- 30 µV
- Current - Supply:
- 9mA
- Current - Output / Channel:
- 40 mA
- Voltage - Supply Span (Min):
- 18 V
- Voltage - Supply Span (Max):
- 50 V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
INA103KU FAQ
1.How can I place an order for INA103KU through Aetrix?
Please submit a Request for Quotation (RFQ) for INA103KU 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 INA103KU reliable?
The price and inventory of INA103KU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA103KU is usually 5 days.
3.What payment methods are accepted for INA103KU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA103KU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA103KU?
INA103KU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA103KU 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 INA103KU?
For technical support, including INA103KU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA103KU requirements.
6.How does Aetrix verify that INA103KU is sourced from the original manufacturer or authorized distributors?
All INA103KU 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 INA103KU meets industry standards.
7.What is the process for return or replacement of INA103KU?
All INA103KU units undergo pre-shipment inspection (PSI). If there is an issue with INA103KU, 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 INA103KU part is unused and in its original packaging.
Return procedure for INA103KU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
INA103KU Tags
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LM358DT
STMicroelectronics
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LM358DR
Texas Instruments
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LM2904DR
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LM358ADR
Texas Instruments
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LM2904DGKR
Texas Instruments
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MCP6006T-E/OT
Microchip Technology
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MCP6006UT-E/OT
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LM324PWR
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LM2902PWR
Texas Instruments
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LM2902DR
Texas Instruments
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LM358P
Texas Instruments
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