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Texas Instruments INA128U/2K5G4
- Part No.:
- INA128U/2K5G4
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
INA128U/2K5G4.pdf
- Description:
- IC INST AMP 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:3,872
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Product details
Overview
INA128U/2K5G4 from Texas Instruments is a precision, low-power instrumentation amplifier designed for high-accuracy signal conditioning of low-level differential sensor outputs in noisy industrial environments. It delivers 50 μV maximum offset voltage, 0.5 μV/°C maximum drift, 120 dB minimum CMRR at G = 100, 1.3 MHz bandwidth (G = 1), and ±40 V input overvoltage protection - enabling robust operation in pressure transmitters and ECG front-ends.
For engineers reviewing the INA128U/2K5G4 datasheet, INA128U/2K5G4 pinout, INA128U/2K5G4 application, or INA128U/2K5G4 equivalent, key selection criteria include gain-setting resistor dependency (G = 1 + 50 kΩ/RG), SOIC-8 package thermal performance (RθJA = 110 °C/W), dual-supply operation (±2.25 V to ±18 V), and CSO: FRE chip-site origin specifications for low-bias-current operation.
Technical Context
The INA128U/2K5G4 implements a three-op-amp architecture with current-feedback input stages, enabling 200 kHz bandwidth even at G = 100. Its laser-trimmed thin-film resistors ensure stable gain accuracy and high common-mode rejection across temperature.
Input overvoltage protection circuitry clamps inputs to ±40 V without damage, while the REF pin allows output level shifting relative to system ground or other reference voltages - critical for interfacing with single-supply ADCs or isolated signal chains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Offset voltage | 50 μV max (RTI) - ensures ≤0.5 mV error at G = 10 for 10 mV input signals |
| CMRR | 120 dB min at G = 100 - rejects >99.999% of 1 V common-mode interference |
| Bandwidth | 1.3 MHz at G = 1 - supports fast transient response in DAQ systems sampling up to 200 kSPS |
| Input bias current | 0.7 nA max (CSO: FRE) - enables use with high-impedance pH or thermocouple sensors |
| Supply range | ±2.25 V to ±18 V - operates from low-voltage battery rails or industrial ±15 V supplies |
| Quiescent current | 700 μA - supports always-on sensor nodes with <1 mW total power at ±5 V |
| Noise density | 8 nV/√Hz at 1 kHz - contributes <1.2 μVRMS integrated noise in 10 kHz BW |
Pinout & Package
INA128U/2K5G4 is housed in an 8-pin SOIC (D) package measuring 4.9 mm × 6 mm, optimized for surface-mount assembly and thermal dissipation (RθJA = 110 °C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 8 | RG (Gain resistor) | Connect external resistor between pins 1 and 8 to set gain per G = 1 + 50 kΩ/RG |
| 2 | VIN− | Inverting input - accepts differential sensor signals with ±40 V fault tolerance |
| 3 | VIN+ | Non-inverting input - high-Z (>10 GΩ) node for direct connection to bridge sensors |
| 4 | V− | Negative supply rail - must be decoupled locally for noise-sensitive applications |
| 5 | REF | Output reference - sets DC level of VO; requires low-impedance connection to maintain CMRR |
| 6 | VO | Differential output - swings to within 1.4 V of rails (CSO: SHE) or 0.15 V (CSO: FRE) |
| 7 | V+ | Positive supply rail - supports split or single-supply configurations up to 36 V total |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed gain network | Ensures ±0.025% gain error at G = 10 (CSO: FRE), eliminating calibration in production test |
| Input overvoltage protection | Withstands ±40 V on VIN+ or VIN− without latch-up or parametric shift - reduces need for external TVS diodes |
| Low-drift reference input | REF pin bias current <1 nA enables direct connection to precision voltage dividers without loading error |
| Wide common-mode range | Accepts inputs from (V−) + 2 V to (V+) − 2 V - accommodates sensor outputs near supply rails in 4–20 mA loop receivers |
| Stable capacitive load drive | Operates reliably with up to 1000 pF load capacitance - simplifies filtering without external isolation resistors |
Applications
| Pressure transmitter | Temperature transmitter |
|---|---|
Use Scenario: Amplifying mV-level output from silicon piezoresistive pressure sensors in HVAC and process control systems. IC Role / Device Role / Timing Role: Precision instrumentation amplifier providing gain, common-mode rejection, and rail-to-rail output swing referenced to system ground. Use Value: 120 dB CMRR suppresses 4–20 mA loop noise; ±40 V input protection eliminates external clamping components. | Use Scenario: Conditioning RTD or thermocouple signals in industrial temperature monitoring modules with 0.1°C resolution. IC Role / Device Role / Timing Role: Low-drift, low-noise IA converting microvolt-level ΔT into clean, amplified analog voltage for ADC digitization. Use Value: 0.5 μV/°C drift ensures <5 μV error over 85°C operating range; 0.7 nA input bias avoids self-heating errors in high-impedance RTD bridges. |
| Weigh scale | Electrocardiogram (ECG) |
Use Scenario: Signal conditioning for full-bridge load cells in commercial and medical weighing platforms requiring legal-for-trade accuracy. IC Role / Device Role / Timing Role: High-gain (G = 500–1000), low-noise instrumentation amplifier with programmable gain and stable DC performance. Use Value: 8 nV/√Hz noise and 0.2 μVPP (0.1–10 Hz) enable sub-gram resolution; laser-trimmed offset minimizes zero-point calibration effort. | Use Scenario: Front-end amplification of 0.5–2 mV cardiac signals in portable and bedside ECG monitors with stringent safety requirements. IC Role / Device Role / Timing Role: Isolated, high-CMRR instrumentation amplifier providing patient-connected input stage with defibrillation protection interface. Use Value: ±40 V input rating meets IEC 60601-1 defib-safe requirements; 120 dB CMRR rejects 50/60 Hz mains interference without notch filtering. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar instrumentation amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA129U/2K5 | Uses 49.4 kΩ gain equation (G = 1 + 49.4 kΩ/RG) for drop-in replacement of legacy devices; identical pinout and specs otherwise | Preferred where existing designs use 49.4 kΩ-based gain tables or require compatibility with older INA129 reference designs | Select INA129U/2K5 only when matching legacy gain resistor values or replacing INA129 in fielded equipment |
| INA828IDR | Lower input bias current (0.6 nA max), lower noise (7 nV/√Hz), same quiescent current; SOIC-8 package | Better suited for ultra-high-impedance sources (e.g., glass pH electrodes) and low-noise DAQ channels requiring <7 nV/√Hz | Choose INA828IDR when upgrading for lower bias current or noise, accepting minor layout rework for same footprint |
Compared with INA129U/2K5, INA128U/2K5 provides standardized 50 kΩ gain scaling and broader legacy design support; versus INA828IDR, it trades 1 nV/√Hz higher noise and 0.1 nA higher bias current for proven long-term stability in cost-sensitive industrial transmitters.
Availability
INA128U/2K5G4 is available at Aetrix Electronics and suitable for pressure transmitter, weigh scale, and ECG monitor designs requiring stable component supply, long-lifecycle availability, and TI-qualified manufacturing traceability.
Supply support for INA128U/2K5G4 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 delivering analog and embedded processing solutions for industrial, automotive, and personal electronics markets.
The INA12x product line was engineered for high-accuracy, low-power signal conditioning in industrial sensor interfaces - emphasizing precision DC performance, rugged input protection, and flexible gain configuration via single external resistor.
FAQ
What is the maximum gain achievable with INA128U/2K5G4?
The INA128U/2K5G4 supports gains from 1 to 10,000 using a single external resistor RG connected between pins 1 and 8, per the equation G = 1 + 50 kΩ/RG. At G = 10,000, RG = 5 Ω (4.99 Ω 1% standard value); bandwidth reduces to ~20 kHz (CSO: SHE) or ~33 kHz (CSO: FRE). The INA128U/2K5G4 maintains functional integrity across this full range under recommended operating conditions.
Does INA128U/2K5G4 require external decoupling capacitors?
Yes - the INA128U/2K5G4 requires local 0.1 μF ceramic decoupling capacitors between V+ (pin 7) and V− (pin 4) and ground, placed as close as possible to the device pins. This prevents high-frequency oscillation and ensures stable operation, especially when driving capacitive loads or operating from noisy power supplies. The INA128U/2K5G4 datasheet specifies these as mandatory for all applications.
Can INA128U/2K5G4 operate from a single 5-V supply?
Yes - the INA128U/2K5G4 supports single-supply operation from 4.5 V to 36 V. When using a 5-V supply, connect V− to ground, V+ to +5 V, and bias the REF pin to mid-supply (e.g., 2.5 V) to maximize output swing. Input common-mode range becomes 2 V to 3 V, and output swing is limited to ~0.15 V to ~4.85 V (CSO: FRE) - verified in the INA128U/2K5G4 electrical characteristics table.
What is the meaning of "CSO: FRE" in INA128U/2K5G4 specifications?
"CSO: FRE" denotes Chip Site Origin: Freescale (now NXP), one of two qualified fabrication flows for the INA128U/2K5G4. It indicates tighter input bias current (0.7 nA max vs. 5 nA for CSO: SHE) and improved output swing (to within 0.15 V of rails), but slightly reduced bandwidth at high gain. All INA128U/2K5G4 units shipped carry CSO: FRE unless otherwise specified - confirmed in TI's SBOS051G datasheet revision history.
How does the REF pin affect common-mode rejection in INA128U/2K5G4?
The REF pin sets the DC output level of the INA128U/2K5G4 and must be driven by a low-impedance source (<1 Ω) to preserve CMRR. A series resistance of just 8 Ω degrades CMRR from 120 dB to ~80 dB at G = 1. For optimal performance, connect REF directly to ground or a buffered reference; avoid routing through long traces or RC filters. This behavior is explicitly characterized in the INA128U/2K5G4 datasheet Figure 8-1 and Section 8.2.
INA128U/2K5G4 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- Instrumentation
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- 4V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 1.3 MHz
- Current - Input Bias:
- 2 nA
- Voltage - Input Offset:
- 10 µV
- Current - Supply:
- 700µA
- Current - Output / Channel:
- 15 mA
- Voltage - Supply Span (Min):
- 4.5 V
- Voltage - Supply Span (Max):
- 36 V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
INA128U/2K5G4 FAQ
1.How can I place an order for INA128U/2K5G4 through Aetrix?
Please submit a Request for Quotation (RFQ) for INA128U/2K5G4 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 INA128U/2K5G4 reliable?
The price and inventory of INA128U/2K5G4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA128U/2K5G4 is usually 5 days.
3.What payment methods are accepted for INA128U/2K5G4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA128U/2K5G4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA128U/2K5G4?
INA128U/2K5G4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA128U/2K5G4 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 INA128U/2K5G4?
For technical support, including INA128U/2K5G4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA128U/2K5G4 requirements.
6.How does Aetrix verify that INA128U/2K5G4 is sourced from the original manufacturer or authorized distributors?
All INA128U/2K5G4 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 INA128U/2K5G4 meets industry standards.
7.What is the process for return or replacement of INA128U/2K5G4?
All INA128U/2K5G4 units undergo pre-shipment inspection (PSI). If there is an issue with INA128U/2K5G4, 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 INA128U/2K5G4 part is unused and in its original packaging.
Return procedure for INA128U/2K5G4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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