INA129P - Precision Low-Power 8-Pin Instrumentation Amp | TI
MPN: INA129P ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
INA129P Overview
An instrumentation amplifier is a specialized analog amplifier that measures a small differential voltage while rejecting common-mode interference. Its internal three-op-amp architecture supports high input impedance and adjustable gain, making it useful when a sensor produces a low-level signal and the surrounding wiring introduces substantial common-mode voltage. The INA129P is therefore positioned between a general-purpose operational amplifier and a more specialized precision measurement amplifier.
Key features include 50 uV maximum offset voltage, 0.5 uV/°C maximum offset drift, 5 nA maximum input bias current, and input protection to ±40 V. The single external gain-setting resistor provides gain adjustment from 1 through 10,000 according to the manufacturer family information, while current-feedback input circuitry maintains useful bandwidth at higher gain. The stated 200 kHz bandwidth at gain 100 makes the device suitable for sensor and instrumentation signal paths rather than only static measurement.
The INA129P uses a low-power instrumentation-amplifier architecture intended for precision measurement systems. Its common-mode rejection helps suppress voltage common to both inputs, and the low offset and drift reduce measurement error in bridge, current, and industrial sensor applications. The ±18 V supply capability provides flexibility for dual-supply analog systems, while the 8-pin PDIP format supports through-hole assembly and prototyping.
Typical uses include bridge and load-cell signal conditioning, industrial process measurement, biomedical instrumentation, current sensing, and precision test equipment. The ±40 V input protection specification is useful when the amplifier is positioned near sensor wiring, although system-level protection and operating conditions still require engineering review.
The principal design consideration is ensuring that the external gain resistor, supply bypassing, input protection, and common-mode range are matched to the sensor. For a new design, verify the exact INA129P pinout and electrical limits against the current Texas Instruments datasheet before layout release.
This page consolidates verified distributor snippets, manufacturer family information, package details, and application guidance, while distinguishing documented specifications from information that requires design-team verification.
Drop-in alternatives for INA129P — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with INA129P (same form factor and footprint) — differing in Product Type, Package, Gain Range, Mounting Type, Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
INA129PA
✅ Drop-In📋 Reference alternative (not in catalog)
INA129U/2K5
✅ Drop-In✓ In Stock
$2.99 / Unit
View Datasheet →INA128PA
✅ Drop-In✓ In Stock
Contact for price
View Datasheet →AD620BNZ
✅ Drop-In📋 Reference alternative (not in catalog)
AD620ANZ
✅ Drop-In✓ In Stock
$6.2 / Unit
View Datasheet →INA129P Maximum Ratings & Electrical Characteristics
| Product Type | Precision low-power instrumentation amplifier |
| Amplifier Circuit Count | 1 |
| Package | 8-pin plastic DIP (PDIP) |
| Mounting Type | Through-hole |
| Maximum Offset Voltage | 50 uV |
| Maximum Offset Drift | 0.5 uV/°C |
| Maximum Input Bias Current | 5 nA |
| Minimum Common-Mode Rejection | 120 dB |
| Input Protection | ±40 V |
| Supply Voltage Range | ±18 V |
| Bandwidth at Gain 100 | 200 kHz |
| Architecture | Three-op-amp instrumentation-amplifier design |
| Gain Adjustment | Single external resistor |
| Gain Range | 1 to 10,000 |
| Temperature Range | -40°C to +85°C |
| Low-Power Feature | Low-power instrumentation-amplifier design |
| Current Feedback | Yes |
INA129P 8-pin plastic dip (pdip) Pin Configuration Guide
Pin configuration for INA129P (8-pin plastic dip (pdip) package). This analog component features input, output, and power supply pins. Refer to the manufacturer datasheet for offset null, compensation, and enable pin configurations. Ideal for signal conditioning and amplifier circuits.
No detailed pinout data available for INA129P.
Refer to the datasheet for full pin configuration.
Typical Applications
INA129P is suitable for 6 applications: Load-Cell and Bridge Sensor Signal Conditioning, Industrial Process Measurement, Current-Sense Amplification, Precision Test and Measurement Instrumentation, Medical and Biomedical Instrumentation, Legacy Through-Hole Sensor Interface.
Load-Cell and Bridge Sensor Signal Conditioning
The INA129P fits bridge-based measurements because its low maximum offset of 50 uV and low offset drift of 0.5 uV/°C help preserve small differential sensor signals. Its minimum common-mode rejection of 120 dB reduces errors when both bridge outputs move together, while the single external gain resistor supports selectable amplification. Use the amplifier near the bridge input and verify bridge excitation, common-mode range, input impedance, and output swing in the complete circuit. The 200 kHz bandwidth at gain 100 provides useful bandwidth for many industrial load-cell and force-sensor systems, but stability and filtering must be checked at the selected gain.
Recommended
Industrial Process Measurement
The INA129P is suitable for low-level process signals that must be measured in the presence of substantial common-mode voltage. Its 120 dB minimum CMR and 5 nA maximum input bias current help reduce errors from long sensor wires and nearby industrial switching equipment. The device's ±18 V supply capability supports dual-supply instrumentation systems, while its three-op-amp architecture simplifies differential measurement around a shared reference. Place the input path close to the sensor, use appropriate filtering, and confirm that the process signal remains inside the amplifier's common-mode and output ranges.
Recommended
Current-Sense Amplification
The INA129P can amplify small differential voltages produced by current-sensing resistors when common-mode rejection and low offset are important. The 50 uV maximum offset and 0.5 uV/°C maximum drift are useful when the measured current changes slowly and the system must retain accuracy across temperature. Its current-feedback input circuitry helps preserve bandwidth at higher gain, including the documented 200 kHz figure at gain 100. The power-loss and accuracy budget should include resistor tolerance, Kelvin routing, amplifier supply noise, saturation recovery, and the sensor's maximum current excursion.
Recommended
Precision Test and Measurement Instrumentation
The INA129P is appropriate for laboratory and industrial test equipment that measures small differential voltages with limited input current. Its low bias current can reduce loading on high-impedance sources, while the high common-mode rejection helps separate the wanted differential signal from fixture or cable-induced common-mode voltage. The PDIP package is convenient for through-hole prototypes and serviceable instrumentation. For precision results, define the gain resistor tolerance, account for input offset and drift, use shielded or guarded wiring where appropriate, and characterize noise and bandwidth at the actual operating gain rather than relying only on headline specifications.
Recommended
Medical and Biomedical Instrumentation
The INA129P can be evaluated for biomedical front ends that acquire small differential sensor voltages, subject to application-specific safety and qualification review. Its low offset and drift reduce baseline measurement error, and its high common-mode rejection can help when the sensor is referenced above ground. The ±40 V input-protection claim should not be treated as a complete medical protection scheme; designers must add the required isolation, clamps, leakage analysis, current limiting, and applicable regulatory controls. Confirm the final amplifier selection against the current datasheet and the complete patient-protection circuit.
Recommended
Legacy Through-Hole Sensor Interface
The INA129P is a practical choice for repairing or extending legacy through-hole instrumentation because it is specified in an 8-pin plastic DIP package. Its one-amplifier instrumentation topology and external gain control support replacement of a traditional three-op-amp measurement front end without introducing a new surface-mount footprint. Before installation, compare the replacement's pin functions, supply polarity, input and output ranges, and gain equation with the original circuit. The package is suitable for prototyping, but DIP footprint compatibility alone does not guarantee electrical equivalence or performance in every original design.
Recommended
Recommended Products Summary
Engineering reference data for INA129P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | INA129PA | INA128P | AD620BNZ | AD620AN |
|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices | Analog Devices |
| Package | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 | PDIP-8 |
| Product Type | Precision low-power instrumentation amplifier | Instrumentation amplifier | Instrumentation amplifier | Instrumentation amplifier | Instrumentation amplifier |
Key Differentiators
- Low offset and drift for precision measurement (vs AD620BNZ)
- High common-mode rejection (vs AD620AN)
- Documented input protection (vs INA128P)
- Through-hole instrumentation-amplifier format (vs AD620AN)
Design Notes
Place the INA129P close to the sensor input connector and route the differential pair together to minimize sensitivity to common-mode electric fields and ground potential differences. Keep the gain-setting resistor close to the device where the datasheet layout permits, and provide solid ground returns for both input and output stages. Because the device uses a precision instrumentation-amplifier topology, a long unprotected input trace can degrade common-mode rejection even when the nominal CMR specification is 120 dB minimum.
Design the supply network for the selected dual-supply voltage while preserving adequate input and output common-mode range. The verified data identifies operation up to ±18 V and input protection to ±40 V, but those figures do not remove the need for supply decoupling, current limiting, and fault analysis. Confirm whether the instrumentation uses dual supplies or a restricted single-supply arrangement, and calculate the amplifier's dissipation from the actual supply voltage, output voltage, and load before selecting copper and package thermal margins.
Do not treat the advertised input-protection rating as a complete input overvoltage solution. Verify the absolute-maximum limits, common-mode range, output swing, and external resistor values from the current Texas Instruments datasheet. Also check the source impedance: the documented 5 nA maximum input bias current can create an error when working with very high sensor impedance. For bridge or current-sense circuits, use a defined reference ground and account for resistor tolerance, offset, drift, and filtering in the system error budget.
Compliance Information
The supplied verified snippets identify the INA129P as a Texas Instruments precision low-power instrumentation amplifier in an 8-pin plastic DIP package, but do not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements. Compliance fields remain unknown rather than inferred.
