INA2128U - Dual Precision Instrumentation Amplifier | TI
MPN: INA2128U ✓ نشطINA2128U نظرة عامة
An instrumentation amplifier is a specialized analog amplifier designed to measure small differential voltages accurately in the presence of large common-mode voltages. Its typical signal-chain hierarchy is differential input -> instrumentation amplifier -> precision analog measurement or control system. The INA2128U supports input-referenced and ground-referenced sensing, where unwanted signals common to both inputs are rejected while the differential component is amplified.
The principal benefits of the INA2128U are its dual-channel configuration, selectable gain from 1 to 10,000, and bandwidth of 200 kHz at a gain of 100. Current-feedback input circuitry helps preserve usable bandwidth as gain increases. The low-power architecture is suitable for compact analog measurement systems, portable instrumentation, and industrial equipment where two precision analog channels must fit into a small board area.
Internally, each channel follows a three-op-amp instrumentation-amplifier topology. Differential input currents are directed toward internal feedback paths, while a single external resistor establishes the gain relationship. Because the circuit supports both single-ended and differential input arrangements, engineers can adapt it to sensor bridges, shunt measurements, and bipolar input signals. The dual organization also allows synchronized acquisition of two related signals without requiring two separate packages.
Typical uses include medical instrumentation, industrial sensor interfaces, battery-powered measurement equipment, current-shunt monitoring, and precision data-acquisition systems. Differential inputs are particularly useful when a sensor produces a small voltage riding on a larger common-mode voltage. Pairing the two channels can also support gain-and-offset measurement, comparator-style monitoring, or sampled systems requiring closely matched amplifier paths.
A practical design must account for the external gain resistor, input and output settling, reference-ground connection, supply decoupling, and common-mode range. Place the gain-setting resistor close to the device and use the manufacturer's recommended layout and decoupling guidance. Maintain the input and output common-mode voltages within the operating limits, and verify system settling at the highest gain required by the measurement bandwidth.
This product page organizes the manufacturer's functional description, package information, comparison considerations, and application guidance into one engineering-focused resource. It also identifies where pin-level and qualification details must be checked in the manufacturer datasheet before a new board is released to production.
بدائل مباشرة لـ INA2128U — نفس الحزمة، متوافق دبوس بدبوس. تُستثنى القطع ذات الحزم المختلفة التي تتطلب تعديل PCB.
لا تتوفر بدائل متوافقة تمامًا لهذا المنتج.
اطلب بدائلINA2128U الحدود القصوى والخصائص الكهربائية
| Amplifier Type | Dual instrumentation amplifier |
| Architecture | Three-op-amp instrumentation-amplifier design |
| Number of Channels | 2 channels |
| Gain Range | 1 to 10,000 |
| Gain Setting Method | 1 external resistor |
| Bandwidth at Gain 100 | 200 kHz |
| Input Circuitry | Current-feedback |
| Input Configuration | Single-ended and differential |
| Power Supply | ±18 V maximum total supply |
| Low Offset Voltage | 25 uV maximum |
| Low Offset Voltage | 2 uV typical |
| العلبة | 16-pin SOIC |
| نوع التركيب | Surface mount |
| حالة RoHS | Compliant |
| MSL | Level 3, 260 C, 168 hours |
دليل تكوين أطراف INA2128U 16-pin soic
تكوين الأطراف لـ INA2128U (حزمة 16-pin soic). يتميز هذا المكوّن التناظري بأطراف الإدخال والإخراج وإمداد الطاقة. راجع ورقة بيانات الشركة المصنعة لتكوينات طرف إلغاء الإزاحة والتعويض والتمكين. مثالي لدوائر تكييف الإشارة والمضخمات.
لا تتوفر بيانات مفصلة لمخطط التوصيلات لـ INA2128U.
راجع ورقة البيانات للحصول على تكوين الأطراف الكامل.
التطبيقات النموذجية
INA2128U مناسب لـ 6 التطبيقs: Medical Instrumentation, Industrial Sensor Interfaces, Battery-Powered Measurement, Current-Shunt Monitoring, Precision Data Acquisition, Bridge and Load-Cell Front Ends.
Medical Instrumentation
The INA2128U fits dual-channel medical instrumentation because each amplifier can acquire a low-level differential signal while rejecting voltage shared by both inputs. Its gain can be set from 1 to 10,000 with one external resistor, allowing the same device family to cover sensor ranges with different amplitudes. The 16-pin SOIC package also helps consolidate two acquisition paths onto a compact analog board. When designing the circuit, check the datasheet's input common-mode range, output swing, offset limits, and noise characteristics over the full selected gain range. Shielding, guarding, leakage management, and isolation requirements remain system-level considerations and must be addressed separately from the amplifier's electrical specifications.
Industrial Sensor Interfaces
The INA2128U is suitable for industrial sensor interfaces that produce a small differential output on top of a larger common-mode voltage. Instrumentation-amplifier operation reduces the common-mode component before the signal reaches downstream conversion or control circuitry, while the externally selectable gain supports sensitivity adjustment without changing the signal path. Two channels can measure related quantities, such as a sensor output and a buffered reference. Place the external gain resistors close to the device, maintain short input routes, and keep sensitive nodes away from switching nodes and high-current returns. The 200 kHz bandwidth quoted at a gain of 100 provides a concrete starting point, but the final signal bandwidth must remain compatible with the chosen gain and settling requirements.
Battery-Powered Measurement
The INA2128U can support compact, battery-powered measurement systems that require two low-level analog channels without using two separate amplifier packages. Its dual-channel organization, broad gain range, and low-power general-purpose architecture suit portable diagnostic and monitoring equipment. The exact battery-life benefit depends on supply voltage, duty cycle, operating gain, and the device's quiescent current under the chosen conditions. Designers should minimize switching activity in the surrounding signal chain, use the lowest supply that satisfies the input and output requirements, and disable unused channels where the system configuration permits. Validate startup and shutdown behavior because portable equipment often cycles power while sensor inputs remain active.
Current-Shunt Monitoring
The INA2128U is appropriate for precision current-shunt monitoring because a shunt produces a differential voltage whose useful signal is much smaller than the voltage common to both measurement terminals. The instrumentation-amplifier configuration rejects that common-mode component, while a user-selected external resistor establishes the required current-to-voltage gain. Two channels allow simultaneous monitoring of a power rail and another shunt measurement. Keep the shunt and amplifier input routing compact because parasitic resistance and unequal traces can unbalance the differential signal. Confirm that the measured shunt voltage remains inside the amplifier's input common-mode range and that the amplified output does not exceed the available output swing.
Precision Data Acquisition
The INA2128U provides two precision analog front-end channels for data-acquisition systems that must measure small differential signals before conversion. Its single-resistor gain setting allows each channel to be adapted to a different sensor range, and the 16-pin SOIC package limits board-space requirements. At a gain of 100, the manufacturer specifies 200 kHz bandwidth, making the device suitable for many sensor-bandwidth applications. The analog designer should account for gain-dependent bandwidth, offset, settling time, and output-swing limits. Place decoupling and gain components close to the package, provide a quiet ground reference, and avoid routing input and output signals in parallel to minimize parasitic feedback through board coupling.
Bridge and Load-Cell Front Ends
The INA2128U can serve as the analog front end for resistive bridges and load cells where the wanted signal is differential and small relative to the bridge excitation. The dual-channel configuration can monitor two bridge-related signals while providing the same selectable-gain architecture on each side. High gain increases sensitivity but also narrows bandwidth and makes layout more sensitive to leakage and parasitic capacitance. Use guarding techniques, clean connectors, and symmetric input routing where practical. Verify that excitation-induced common-mode voltage stays within the input common-mode range and that the output remains inside the amplifier's linear operating region at the maximum expected load and temperature.
بيانات مرجعية هندسية لـ INA2128U — المقارنة وإرشادات التصميم ومعلومات الامتثال.
دليل الاختيار
A single-channel INA128U may be preferable when only one signal is measured or separate packages improve placement and thermal isolation. A fixed-gain INA2133 can simplify a design when the required gain is known and resistor-free adjustment is unnecessary, but it is not a pin-for-pin substitute without verification. For any alternative, compare the complete pinout, input and output ranges, supply limits, gain accuracy, offset, drift, bandwidth, settling, quiescent current, and package. Treat similarly packaged amplifiers as candidates rather than drop-in replacements until both electrical and pin compatibility have been demonstrated.
المقارنة مع البدائل
| المعامل | هذا المنتج |
|---|---|
| Package | 16-pin SOIC |
| Brand | Texas Instruments |
| Amplifier Type | Dual instrumentation amplifier |
| Number of Channels | 2 channels |
| Architecture | Three-op-amp design |
| Gain Range | 1 to 10,000 |
| Bandwidth at Gain 100 | 200 kHz |
| Input Circuitry | Current-feedback |
| Input Configuration | Single-ended and differential |
| Maximum Total Supply | ±18 V |
| Offset Voltage | 2 uV typical, 25 uV maximum |
| RoHS Status | Compliant |
أبرز الفروقات
- Two precision channels in one package (مقابلSingle-channel INA128U)
- Externally selectable gain across a wide range (مقابلINA2133UE4)
- Current-feedback input architecture (مقابلINA128U)
ملاحظات التصميم
Place the INA2128U gain-setting resistors directly beside the associated device pins and route each input as a short, tightly coupled pair. Long or asymmetric input traces can create unequal parasitic capacitance and resistance, reducing common-mode rejection and settling performance. Keep the two channels physically separated where their signals are independent, and avoid routing sensitive inputs beneath or parallel to digital clocks, DC-DC converter switches, and high-current return paths.
Follow the Texas Instruments datasheet when placing supply bypass capacitors and selecting the supply configuration. The INA2128U supports operation from dual supplies up to ±18 V, but input and output voltages must remain within their respective operating ranges. Check startup and shutdown sequencing, use a low-noise supply for precision measurements, and verify that rail transients do not move either input or output beyond the allowed common-mode and swing limits.
Do not select the gain from a nominal formula without checking settling at the operating bandwidth. The INA2128U reaches 200 kHz at a gain of 100, but higher gains reduce available bandwidth and can increase sensitivity to gain error and component parasitics. Also verify resistor tolerance and temperature coefficient when gain accuracy matters. Use the manufacturer test conditions to determine whether the measurement requires offset correction, calibration, or a lower bandwidth.
معلومات الامتثال
RoHS compliance and MSL Level 3, 260 C, 168 hours are identified for the INA2128U. No additional compliance status is stated.