INA157UA - 4MHz Difference Amplifier | Texas Instruments
부품 번호: INA157UA ✓ 활성INA157UA 개요
A difference amplifier is a specialized instrumentation amplifier building block that measures the voltage difference between two inputs rather than amplifying either input relative to ground. In the broader semiconductor hierarchy, the INA157UA belongs to the amplifier IC family, specifically the difference-amplifier and instrumentation-signal-chain categories used for current sensing, bridge sensing, and measurement systems.
Key features include a 4 MHz bandwidth, low maximum offset voltage of ±500 µV, low offset drift of ±2 µV/°C, and low maximum gain error of ±0.05%. The integrated resistor network eliminates the component-matching and resistor-ratio errors normally associated with discrete difference amplifiers. The INA157UA is available in the 8-pin SOIC surface-mount package.
The internal architecture combines a precision operational amplifier with a precision, laser-trimmed resistor network. Its differential input arrangement supports accurate measurement of small voltage differences in the presence of substantially larger common-mode voltages. The 4 MHz bandwidth makes the device suitable for signal chains that require faster response than a conventional precision instrumentation amplifier while retaining integrated gain accuracy.
Typical applications include low-side and high-side current sensing, bridge and strain-gauge signal conditioning, industrial process measurement, and differential sensor interfaces. In these systems, the INA157UA converts a small differential sensor voltage into a single-ended output while suppressing common-mode noise. It is particularly useful where an eight-pin surface-mount footprint and integrated resistor network simplify board design.
When designing with the INA157UA, verify the input and output voltage limits, supply headroom, common-mode range, and operating-temperature grade against the manufacturer datasheet. Input and output layout should minimize parasitic capacitance and feedback-loop area, while a clean analog ground return is important for precision measurement. Bypass placement and trace routing should follow the datasheet recommendations rather than generic high-frequency layouts.
This page combines verified manufacturer and distributor information, same-package substitution analysis, practical design guidance, and specification-by-specification comparison. It is intended to help engineers identify the INA157UA, evaluate genuine drop-in alternatives, and implement the device correctly in precision analog signal chains.
드롭인 대체품: INA157UA — 동일 패키지, 핀 호환. PCB 재작업이 필요한 다른 패키지 부품은 제외됩니다.
이 시리즈의 변형
다음과 드롭인 호환되는 동일 시리즈 모델: INA157UA (동일 폼 팩터 및 풋프린트) — 차이점: Bandwidth, Operating Temperature Range, Package, AEC-Q100 Qualification, Internal Resistor Network.
INA157U
✅ 드롭인가격 문의
데이터시트 보기 →INA154UAG4
✅ 드롭인📋 참조 대체품 (카탈로그에 없음)
INA157UA 최대 정격 & 전기적 특성
| Device Type | High-speed, precision difference amplifier |
| Number of Amplifier Channels | 1 channel |
| Bandwidth | 4 MHz |
| Offset Voltage | ±500 µV maximum |
| Offset Voltage Drift | ±2 µV/°C maximum |
| Gain Error | ±0.05% maximum |
| Differential Gain | 1 V/V |
| Internal Resistor Network | Precision, laser-trimmed |
| 패키지 | 8-pin SOIC (D) |
| 실장 유형 | Surface mount |
| 동작 온도 범위 | -55 °C to +125 °C |
| RoHS 상태 | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | not_applicable |
INA157UA 핀 구성
| 핀 1 | RG — Gain resistor connection |
| 핀 2 | IN- — Inverting differential input |
| 핀 3 | IN+ — Non-inverting differential input |
| 핀 4 | V- — Negative power supply connection |
| 핀 5 | RG — Gain resistor connection |
| 핀 6 | OUT — Amplifier output |
| 핀 7 | NC — Not connected |
| 핀 8 | V+ — Positive power supply connection |
일반적인 애플리케이션
INA157UA 적합 용도: 6 애플리케이션s: Low-Side Current Sensing, Bridge Sensor Signal Conditioning, Strain-Gauge Measurement, Industrial Process Measurement, High-Speed Differential Sensing, Sensor Interface and Signal Conditioning.
Low-Side Current Sensing
The INA157UA fits low-side current sensing because its 4 MHz bandwidth captures shunt-voltage transients more effectively than a slow precision amplifier. Place the shunt between the load and ground, route the two differential inputs directly to the shunt pads, and use the integrated laser-trimmed resistor network to produce a single-ended measurement. This eliminates the matched external divider normally required by a discrete difference amplifier and supports accurate sensing of the INA157UA's stated ±500 µV maximum offset and ±0.05% maximum gain error. Before implementation, verify that the load-supply common-mode voltage remains inside the datasheet input range and that the measured output stays within the output-swing limits.
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Bridge Sensor Signal Conditioning
The INA157UA is appropriate for bridge sensor front ends that generate a small differential voltage superimposed on a larger common-mode level. Its 4 MHz bandwidth and integrated precision resistor network provide a compact way to condition bridge excitation outputs while rejecting common-mode error. Place the differential inputs symmetrically near the bridge connections, keep the feedback and output routing short, and provide a clean analog ground to the device. The laser-trimmed network avoids the resistor-ratio mismatch associated with discrete implementations and supports the stated ±0.05% maximum gain error. Supply voltage, bridge excitation range, and input common-mode limits must be confirmed directly from the manufacturer datasheet before selecting external resistors or filtering.
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Strain-Gauge Measurement
The INA157UA can serve as the first difference-amplifier stage in a strain-gauge measurement system, where small millivolt-level differential signals must be distinguished from a substantial excitation common-mode voltage. Its 4 MHz bandwidth supports higher-bandwidth strain instrumentation than a conventional low-frequency instrumentation amplifier, while the integrated precision network reduces external resistor-matching errors. Position the amplifier close to the strain bridge, route input pairs together, and use a low-impedance reference and ground plane. The stated ±500 µV maximum offset and ±2 µV/°C maximum drift establish useful initial error targets, although the complete input range and offset-correction requirements should be checked in the manufacturer datasheet.
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Industrial Process Measurement
The INA157UA suits industrial process-measurement front ends where a sensor produces a differential voltage and the controller requires a grounded, single-ended signal. The device combines one precision amplifier channel with a laser-trimmed internal network in an 8-pin SOIC package, reducing analog board area without requiring an external precision resistor array. Its 4 MHz bandwidth is useful for process signals with moderate dynamic content, and the measured gain error is specified as no more than ±0.05%. In deployed equipment, isolate noisy switching nodes from the input pair, use a dedicated analog-ground return, and place supply bypassing close to the amplifier. Verify industrial temperature requirements against the exact INA157UA ordering information.
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High-Speed Differential Sensing
The INA157UA is appropriate for high-speed differential sensing when the system must preserve a 4 MHz signal bandwidth while rejecting common-mode components. The part accepts two differential inputs and provides a precision single-ended output through an integrated laser-trimmed network. This allows a compact analog front end to be placed close to the sensing element, reducing susceptibility to external pickup. Layout quality remains important: route the input pair as a matched pair, minimize connector and test-point discontinuities, and use a quiet ground reference. Because the supplied verified data does not state settling time, slew rate, or common-mode rejection, those limits must be obtained from the manufacturer datasheet before setting the system bandwidth.
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Sensor Interface and Signal Conditioning
The INA157UA can simplify a generic sensor-interface stage by converting a differential sensor output to a single-ended voltage while attenuating common-mode noise. Its 4 MHz bandwidth gives designers headroom beyond slow precision-amplifier implementations, and the laser-trimmed network removes the need to match discrete resistors. The device is particularly useful where space is constrained because the complete function occupies an 8-pin SOIC package. Keep the sensor and amplifier on the same side of analog partition boundaries, provide local supply bypassing, and avoid routing the differential pair beside switching-current paths. The stated ±500 µV maximum offset and ±2 µV/°C maximum drift are useful for initial error budgets, but the final accuracy also depends on the sensor, reference, and system calibration.
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추천 제품 요약
엔지니어링 참조 데이터: INA157UA — 비교, 설계 지침 및 규정 준수 정보.
선택 가이드
대체품과의 비교
| 파라미터 | 이 제품 | INA157U | INA154UAG4 |
|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 8-pin SOIC (D) | 8-pin SOIC (D) - same | 8-pin SOIC (D) - same |
| Device Type | High-speed, precision difference amplifier | High-speed, precision difference amplifier | Precision difference amplifier |
| Bandwidth | 4 MHz | 4 MHz | 3.1 MHz |
| Number of Channels | 1 channel | 1 channel | 1 channel |
주요 차별점
- Higher verified bandwidth than the INA154UAG4 (vs INA154UAG4)
- Extended-temperature ordering option (vs INA157U)
- Integrated precision resistor network (vs INA154UAG4)
설계 노트
Route the INA157UA differential input pair as a tightly coupled pair with matched routing lengths and minimal area between the source and the amplifier. Place the device close to the sensor or shunt so that the input signal is converted before board traces can pick up noise. Keep the input nodes away from switching nodes, inductors, and high-current return paths. Although the specified bandwidth is 4 MHz, using short traces and a quiet ground reference prevents parasitic feedback from degrading common-mode rejection.
Place supply bypassing directly at the INA157UA supply pins and maintain a low-impedance connection to the analog ground reference. The supplied verified data does not include the permitted supply-voltage range, output swing, or recommended capacitor values, so those values must be taken from the manufacturer datasheet rather than estimated. Verify startup sequencing, positive and negative rail limits, and output-headroom margin before applying power. Do not infer capacitor or stability guidance solely from the generic instruction to bypass the device.
Do not treat matching package names as proof that any INA-family amplifier is electrically interchangeable. The INA154UAG4 has a verified 3.1 MHz bandwidth compared with the INA157UA's 4 MHz, while the INA157U is associated with a reduced -40 °C to +85 °C family range rather than the INA157UA's -55 °C to +125 °C rating. Before substitution, compare pin names, supply voltage, input common-mode range, output swing, offset, gain error, and absolute maximum ratings. Also verify that the alternative's resistor-network connections and intended gain configuration match the original board.
Use a continuous analog ground region beneath and around the INA157UA, with separate return paths for noisy digital or switching currents. If additional filtering is required, place passive components close to the relevant amplifier pins and include their capacitance in stability and bandwidth analysis. The integrated laser-trimmed resistor network improves gain accuracy, but it does not compensate for unstable reference grounding, excessive common-mode voltage, or output saturation. Confirm settling behavior and maximum output conditions from the manufacturer datasheet before operating near the stated 4 MHz bandwidth.
규정 준수 정보
The supplied verified sources do not explicitly provide RoHS, REACH, lead-free, halogen-free, or conflict-minerals declarations for INA157UA. The device is an amplifier IC and is not identified as an AEC-Q100-qualified automotive part.
