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Texas Instruments INA155U/2K5
- Part No.:
- INA155U/2K5
- Manufacturer:
- Texas Instruments
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
INA155U/2K5.pdf
- Description:
- IC INST AMP 1 CIRCUIT 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,399
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Product details
Overview
INA155U/2K5 from Texas Instruments (formerly Burr-Brown) is a single-supply, rail-to-rail output CMOS instrumentation amplifier with fixed gain options of 10 V/V or 50 V/V, ±200 µV max input offset voltage, ±5 µV/°C drift, and 550 kHz bandwidth at G = 10. It operates from +2.7 V to +5.5 V and is specified over –55°C to +125°C for industrial sensor signal conditioning.
For engineers reviewing the INA155U/2K5 datasheet, INA155U/2K5 pinout, INA155U/2K5 application, or INA155U/2K5 equivalent, key selection criteria include its rail-to-rail output swing within 10 mV of rails, ultra-low input bias current (0.2 pA typ), wide common-mode input range (0.2 V to 5.2 V at VS = 2.7 V), low THD+N in audio and A/D driver roles, and SO-8 package compatibility with legacy layouts.
Technical Context
The INA155U/2K5 integrates two precision op-amps (A1 and A2) in a classic three-op-amp instrumentation topology with internal laser-trimmed thin-film resistors. Gain is set by pin-strapping pins 1 and 8 (open = G = 10, shorted = G = 50) or via external RG resistor per G = 10 + 400 kΩ/(10 kΩ + RG).
Its rail-to-rail output stage uses complementary common-source transistors, enabling full-swing operation into 10 kΩ loads while maintaining <0.1% gain error. Input stage employs CMOS inputs with 10¹³ Ω || 3 pF impedance, and internal ESD diodes clamp inputs to rails ±0.5 V - requiring current limiting for overvoltage protection.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain Options | Fixed 10 V/V (pins 1 & 8 open) or 50 V/V (pins 1 & 8 shorted); no external resistors needed for standard gains |
| Input Offset Voltage | ±200 µV max (–55°C to +125°C); enables high-accuracy bridge sensing without trimming |
| Input Bias Current | 0.2 pA typical; supports >100 MΩ source impedances (e.g., piezoelectric sensors, pH electrodes) |
| Bandwidth | 550 kHz at G = 10; sufficient for 100 kSPS sampling with <0.1% settling in ≤5 µs |
| Rail-to-Rail Output | Swings within 5–10 mV of V+ and V– at RL ≥ 10 kΩ; eliminates need for dual supplies in portable systems |
| Supply Range | +2.7 V to +5.5 V; compatible with Li-ion, 3.3 V, and 5 V logic rails |
| CMRR | 92 dB min at G = 10 (VS = 5.5 V); rejects noise from noisy industrial power rails |
Pinout & Package
INA155U/2K5 is housed in an SO-8 surface-mount package (JEDEC MS-012, drawing D), 4.9 mm × 3.9 mm × 1.75 mm, with standard lead pitch of 1.27 mm. Thermal resistance θJA = 150 °C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (RG) | Gain select terminal | Connect to pin 8 for G = 50; leave open for G = 10; external RG sets intermediate gains |
| 2 (VIN–) | Inverting input | Differential input node; requires matched bias return path for optimal CMRR |
| 3 (VIN+) | Non-inverting input | Differential input node; high-impedance CMOS input accepts microvolt-level signals |
| 4 (V–) | Negative supply | Ground reference for single-supply operation; must be low-impedance |
| 5 (Ref) | Output reference | Sets output common-mode level (e.g., VS/2); >200 Ω series resistance degrades CMRR to ~80 dB |
| 6 (VOUT) | Amplified output | Rail-to-rail output capable of driving 10 kΩ loads or capacitive A/D inputs directly |
| 7 (V+) | Positive supply | Accepts +2.7 V to +5.5 V; decoupling capacitor required near pin |
| 8 (RG) | Gain select terminal | Paired with pin 1; low-impedance connection critical for G = 50 accuracy (≤20 Ω) |
Key Features
| Feature | Design Value |
|---|---|
| Laser-trimmed thin-film resistors | Enables ±0.02% gain error at G = 10 and ±0.05% at G = 50 over temperature |
| Ultra-low input bias current | 0.2 pA typical allows direct interfacing with high-Z sources like RTDs, thermocouples, and piezo sensors |
| Single-supply rail-to-rail output | Eliminates need for negative supply in battery-powered data loggers and portable medical devices |
| Wide common-mode input range | 0.2 V to 2.5 V at VS = 2.7 V supports operation near ground in low-voltage systems |
| Fast overload recovery | 0.2 µs recovery from 50% input overload enables robust performance in transient-prone industrial environments |
Applications
| Bridge Sensor Amplifier | ECG Signal Conditioning |
|---|---|
Use Scenario: Amplifying mV-level differential output from a Wheatstone bridge strain gauge or load cell powered from +5 V. IC Role / Device Role / Timing Role: Instrumentation amplifier providing fixed G = 10 or G = 50 gain, referenced to VS/2, with rail-to-rail output driving ADC input. Use Value: ±200 µV offset ensures <0.1% error in 10-bit measurement of 20 mV full-scale bridge output. | Use Scenario: Front-end amplification of low-amplitude, high-impedance biopotential signals from ECG electrodes. IC Role / Device Role / Timing Role: Precision IA rejecting 50/60 Hz common-mode interference while preserving sub-mV differential cardiac waveform. Use Value: 92 dB CMRR at G = 10 suppresses line noise; 0.2 pA bias current prevents electrode polarization errors. |
| Single-Supply A/D Driver | PCMCIA Data Acquisition |
Use Scenario: Driving the capacitive input of a 12-bit SAR ADC (e.g., ADS7818) operating from +5 V. IC Role / Device Role / Timing Role: High-speed buffer with 6.5 V/µs slew rate and 5 µs 0.1% settling time at G = 10. Use Value: Direct interface eliminates external op-amp buffer, reducing board area and power in compact DAQ modules. | Use Scenario: Signal conditioning in PCMCIA cards for portable test equipment requiring low power and small footprint. IC Role / Device Role / Timing Role: Low-quiescent-current (1.7 mA) IA delivering rail-to-rail output into 3.3 V logic-compatible ADCs. Use Value: SO-8 package fits tight PCMCIA card spacing; +2.7 V minimum supply enables operation from USB bus power. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar instrumentation amplifier applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA126UA/2K5 | Lower quiescent current (1.3 mA), lower bandwidth (150 kHz), JFET input (IB = 25 pA), G = 5–10,000 via RG | Better for ultra-low-power, low-frequency sensor nodes; less suitable for fast A/D driving | Select when power budget <1.5 mA and bandwidth <200 kHz suffices; avoid for G = 10/50 fixed-gain simplicity |
| AD8221ARMZ-REEL | Higher precision (±25 µV VOS), wider bandwidth (825 kHz at G = 10), higher cost, MSOP-8 only | Preferred for medical-grade ECG or precision weigh scales where offset drift dominates error budget | Choose when ±5 µV/°C drift is insufficient and total error must stay <50 µV over –40°C to +85°C |
Compared with INA155U/2K5, INA126UA/2K5 trades bandwidth and ease of gain setting for lower power, while AD8221ARMZ-REEL delivers superior DC precision and speed at higher cost and reduced package flexibility - making INA155U/2K5 optimal for cost-sensitive, medium-speed industrial sensor interfaces requiring fixed-gain simplicity and SO-8 compatibility.
Availability
INA155U/2K5 is available at Aetrix Electronics and suitable for industrial sensor amplifiers, medical ECG front-ends, and PCMCIA data acquisition systems requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for INA155U/2K5 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 components for industrial, medical, and test equipment markets.
The INA155 belongs to TI's instrumentation amplifier product line, designed specifically for low-voltage, single-supply applications demanding rail-to-rail output, ultra-low input bias current, and fixed-gain simplicity in harsh environmental conditions.
FAQ
What is the maximum operating temperature range for the INA155U/2K5?
The INA155U/2K5 is fully specified over –55°C to +125°C and rated for operation from –65°C to +150°C. Its SO-8 package has θJA = 150 °C/W, and thermal performance is validated across this full range per the official datasheet specifications.
Can the INA155U/2K5 operate from a +3.3 V supply?
Yes, the INA155U/2K5 operates from +2.7 V to +5.5 V, making +3.3 V fully supported. At VS = 3.3 V, the common-mode input range is approximately 0.2 V to 3.0 V, and rail-to-rail output swing remains within 10 mV of rails under 10 kΩ load - confirmed in the datasheet's Typical Performance Curves.
How is gain selected on the INA155U/2K5?
Gain is selected by configuring pins 1 (RG) and 8 (RG): leaving both pins open sets G = 10 V/V; shorting them together sets G = 50 V/V. For gains between 10 and 50, an external resistor RG is placed between pins 1 and 8 using G = 10 + 400 kΩ/(10 kΩ + RG).
Does the INA155U/2K5 require external offset trimming?
No - the INA155U/2K5 is laser-trimmed for ±200 µV max input offset voltage over temperature, eliminating the need for external trimming in most applications. Optional offset adjustment can be achieved by applying a correction voltage to the Ref pin, but this is rarely required in practice.
Is the INA155U/2K5 RoHS compliant and lead-free?
Yes, the INA155U/2K5 is RoHS compliant and lead-free, with NIPDAU finish and Green (low-halogen) packaging per TI's Package Option Addendum. It meets JEDEC MSL Level-2-260°C-1 year and is qualified for industrial temperature operation.
INA155U/2K5 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Amplifier Type:
- Instrumentation
- Number of Circuits:
- 1
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 6.5V/µs
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 550 kHz
- Current - Input Bias:
- 1 pA
- Voltage - Input Offset:
- 200 µV
- Current - Supply:
- 1.7mA
- Current - Output / Channel:
- 50 mA
- Voltage - Supply Span (Min):
- 2.7 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- -55°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
INA155U/2K5 FAQ
1.How can I place an order for INA155U/2K5 through Aetrix?
Please submit a Request for Quotation (RFQ) for INA155U/2K5 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 INA155U/2K5 reliable?
The price and inventory of INA155U/2K5 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for INA155U/2K5 is usually 5 days.
3.What payment methods are accepted for INA155U/2K5?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for INA155U/2K5 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for INA155U/2K5?
INA155U/2K5 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your INA155U/2K5 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 INA155U/2K5?
For technical support, including INA155U/2K5 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your INA155U/2K5 requirements.
6.How does Aetrix verify that INA155U/2K5 is sourced from the original manufacturer or authorized distributors?
All INA155U/2K5 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 INA155U/2K5 meets industry standards.
7.What is the process for return or replacement of INA155U/2K5?
All INA155U/2K5 units undergo pre-shipment inspection (PSI). If there is an issue with INA155U/2K5, 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 INA155U/2K5 part is unused and in its original packaging.
Return procedure for INA155U/2K5:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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