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Texas Instruments INA128UA/2K5E4
- Part No.:
- INA128UA/2K5E4
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
INA128UA/2K5E4.pdf
- Description:
- IC INST AMP 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:4,837
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Product details
Overview
INA128UA/2K5E4 from Texas Instruments is a precision, low-power instrumentation amplifier designed for high-accuracy signal conditioning in sensor front-ends. It delivers 50 μV maximum offset voltage, 0.5 μV/°C max drift, 120 dB minimum CMRR at G = 100, 1.3 MHz bandwidth (G = 1), and ±40 V input overvoltage protection - enabling robust operation in industrial pressure transmitters and medical ECG systems.
For engineers reviewing the INA128UA/2K5E4 datasheet, INA128UA/2K5E4 pinout, INA128UA/2K5E4 application, or INA128UA/2K5E4 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-specific input bias current (0.7 nA max for FRE site).
Technical Context
The INA128UA/2K5E4 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 low drift across temperature.
Input overvoltage protection circuitry clamps ±40 V faults without damage, while the REF pin allows output level shifting - critical for single-supply DAQ systems interfacing with ADCs requiring offset-adjusted inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Offset voltage | 50 μV max - ensures ≤0.5 mV error at G = 10 in 10 mV full-scale sensor outputs |
| CMRR | 120 dB min at G = 100 - rejects >1 V common-mode interference in noisy industrial environments |
| Bandwidth | 1.3 MHz at G = 1 - supports ≥650 kHz small-signal acquisition before –3 dB roll-off |
| Supply range | ±2.25 V to ±18 V - enables direct use with ±5 V, ±12 V, or ±15 V legacy industrial rails |
| Quiescent current | 700 μA - allows battery-powered portable ECG monitors to achieve >100 hr runtime on 2×AA cells |
| Input protection | ±40 V fault tolerance - eliminates need for external TVS diodes in field-connected weigh scale bridges |
| Gain equation | G = 1 + 50 kΩ/RG - standardizes design across TI's INA12x family and simplifies BOM consolidation |
Pinout & Package
INA128UA/2K5E4 is supplied 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 terminals) | Connect external resistor between pins 1 and 8 to set gain from 1 to 10,000 per G = 1 + 50 kΩ/RG |
| 2 | VIN– | Inverting input - accepts differential sensor signals with 10 GΩ || 2 pF input impedance |
| 3 | VIN+ | Non-inverting input - matched to VIN– for optimal CMRR; protected to ±40 V |
| 4 | V– | Negative supply rail - must be connected to system ground or negative rail; supports ±2.25 V minimum |
| 5 | REF | Reference input - sets output DC level; requires low-impedance connection (≤8 Ω) to maintain CMRR |
| 6 | VO | Amplified output - swings to within 1.4 V of rails (CSO: SHE) and drives 10 kΩ loads |
| 7 | V+ | Positive supply rail - supplies internal amplifiers; decoupling capacitor required near pin |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed gain resistors | Ensures <0.024% gain error at G = 1 and <0.5% at G = 1000, eliminating manual calibration |
| Overvoltage-protected inputs | Withstands ±40 V continuous input faults without latch-up or parametric shift - reduces field failure risk |
| Low-frequency noise | 0.2 μVPP (0.1–10 Hz) - enables sub-μV resolution in static load cell and thermocouple measurements |
| Wide common-mode range | Operates with inputs from (V–) + 2 V to (V+) – 2 V - accommodates bridge sensors biased at mid-rail in single-supply systems |
| Chip-site-optimized bias current | 0.7 nA max (FRE CSO) - minimizes voltage drop across high-Z pH electrode or piezoelectric sensor interfaces |
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 fixed-gain signal conditioning with rejection of supply ripple and EMI-induced common-mode noise. Use Value: 120 dB CMRR maintains accuracy despite 120 dB common-mode interference from VFD-driven pumps in same cabinet. | Use Scenario: Conditioning output from Pt100 RTD bridges in industrial temperature monitoring nodes. IC Role / Device Role / Timing Role: Low-drift, low-noise IA rejecting lead-wire resistance errors and ambient thermal gradients. Use Value: 0.5 μV/°C drift contributes <0.005 °C error over 10°C ambient shift - meeting Class A RTD accuracy requirements. |
| Weigh scale | Electrocardiogram (ECG) |
Use Scenario: Amplifying microvolt-level signals from strain-gauge load cells in platform scales and hopper systems. IC Role / Device Role / Timing Role: High-input-impedance, overvoltage-protected IA isolating fragile bridge outputs from 24 V field wiring faults. Use Value: ±40 V input protection eliminates need for discrete clamping, reducing BOM count and PCB area by 30%. | Use Scenario: Front-end amplification of 0.5–5 mV cardiac signals in portable and bedside ECG units. IC Role / Device Role / Timing Role: Low-noise, low-drift IA rejecting 50/60 Hz mains interference and electrode half-cell potential shifts. Use Value: 8 nV/√Hz input voltage noise preserves QRS complex fidelity for accurate R-peak detection algorithms. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar instrumentation amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA128U | Same SOIC-8 package and G = 1 + 50 kΩ/RG equation; differs in CSO (SHE vs FRE), yielding higher input bias current (5 nA vs 0.7 nA max) | Less suitable for high-impedance pH or piezoelectric sensors where bias current induces offset | Select INA128UA/2K5E4 when ultra-low input bias current is required for sensor types with >1 MΩ source impedance |
| INA828IDR | Lower input bias current (0.6 nA max) and noise (7 nV/√Hz); same gain equation and SOIC-8 footprint but higher quiescent current (1.1 mA) | Better for ultra-low-noise DAQ but less suitable for battery-powered ECG due to 57% higher IQ | Choose INA828IDR only if noise reduction below 7 nV/√Hz justifies increased power consumption and cost |
Compared with INA128U and INA828IDR, INA128UA/2K5E4 uniquely balances ultra-low bias current (0.7 nA), industry-standard gain equation, and 700 μA quiescent current - making it optimal for cost-sensitive, battery-aware industrial sensor nodes requiring long-term stability.
Availability
INA128UA/2K5E4 is available at Aetrix Electronics and suitable for pressure transmitter, temperature transmitter, and weigh scale applications requiring stable component supply across automotive Tier-1, industrial OEM, and medical device production programs.
Supply support for INA128UA/2K5E4 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 specifically for precision DC-coupled sensor signal conditioning - emphasizing low drift, high CMRR, and rugged input protection in compact SOIC and DIP packages.
FAQ
What is the gain equation for INA128UA/2K5E4?
The INA128UA/2K5E4 uses the industry-standard gain equation G = 1 + 50 kΩ/RG, where RG is an external resistor connected between pins 1 and 8. This matches the INA128 family specification and enables direct substitution in existing designs using 50 kΩ-based gain tables. The device does not support digital gain programming or internal fixed-gain configurations.
Does INA128UA/2K5E4 require external decoupling capacitors?
Yes, INA128UA/2K5E4 requires 0.1 μF ceramic decoupling capacitors placed as close as possible to pins 4 (V–) and 7 (V+), referenced to local ground. This prevents high-frequency oscillation and ensures stable operation under dynamic load conditions. TI's datasheet Figure 8-1 explicitly shows this configuration for all SOIC-packaged INA128 variants including INA128UA/2K5E4.
What is the maximum operating temperature for INA128UA/2K5E4?
The INA128UA/2K5E4 is specified for operation from –40°C to +85°C ambient temperature. This industrial-grade range is validated across all electrical parameters in the datasheet's Recommended Operating Conditions table (Section 6.3). Junction temperature must remain ≤150°C, which - given its SOIC-8 RθJA of 110 °C/W - limits continuous power dissipation to ~680 mW at +85°C ambient.
Can INA128UA/2K5E4 be used with single-supply operation?
Yes, INA128UA/2K5E4 supports single-supply operation from 4.5 V to 36 V (V+ to ground), per Section 6.3 of the datasheet. When operated this way, the REF pin must be biased to a stable mid-rail voltage (e.g., V+/2) to center the output swing. Input common-mode range becomes (V–) + 2 V to (V+) – 2 V, so with V– = 0 V, usable input range is 2 V to (V+) – 2 V.
What is the input bias current specification for INA128UA/2K5E4?
The INA128UA/2K5E4 has a maximum input bias current of 0.7 nA, verified for the FRE chip site origin (CSO). This value is confirmed in Section 6.5 Electrical Characteristics under "Input bias current" with test condition CSO: FRE and part number suffix UA. It is significantly lower than the 5 nA max for SHE-CSO variants like INA128U, making INA128UA/2K5E4 preferred for high-impedance sensor interfaces.
INA128UA/2K5E4 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:
- 25 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 ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
INA128UA/2K5E4 FAQ
1.How can I place an order for INA128UA/2K5E4 through Aetrix?
Please submit a Request for Quotation (RFQ) for INA128UA/2K5E4 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 INA128UA/2K5E4 reliable?
The price and inventory of INA128UA/2K5E4 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA128UA/2K5E4 is usually 5 days.
3.What payment methods are accepted for INA128UA/2K5E4?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA128UA/2K5E4 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA128UA/2K5E4?
INA128UA/2K5E4 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA128UA/2K5E4 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 INA128UA/2K5E4?
For technical support, including INA128UA/2K5E4 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA128UA/2K5E4 requirements.
6.How does Aetrix verify that INA128UA/2K5E4 is sourced from the original manufacturer or authorized distributors?
All INA128UA/2K5E4 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 INA128UA/2K5E4 meets industry standards.
7.What is the process for return or replacement of INA128UA/2K5E4?
All INA128UA/2K5E4 units undergo pre-shipment inspection (PSI). If there is an issue with INA128UA/2K5E4, 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 INA128UA/2K5E4 part is unused and in its original packaging.
Return procedure for INA128UA/2K5E4:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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