LT1457S8 - Dual Precision JFET Op Amp | Analog Devices
MPN: LT1457S8 ✓ Hoạt độngLT1457S8 Tóm tắt
A JFET-input operational amplifier is a voltage-amplifier IC whose field-effect input stage uses junction FETs. Within the semiconductor hierarchy, the LT1457S8 is an op amp, analog amplifier IC, and signal-conditioning component. Its low-bias-current input stage is useful when measuring signals from high-impedance sources, while its large-capacitive-load optimization helps maintain stability in practical analog circuits.
The principal features include a dual amplifier configuration, precision DC input offset of 220 µV, very low bias and offset currents at elevated temperature, 130 dB channel separation, and support for input and output voltages up to ±20 V according to distributor data. These characteristics make the LT1457 suitable for precision buffers, instrumentation stages, sensors, and low-frequency signal-conditioning applications.
The JFET input stage provides high input impedance without introducing the bias current associated with bipolar transistor inputs. However, users should distinguish that benefit from the LT1457's comparatively low operating speed. Analog Devices identifies the LT1057 as approximately three times faster, while noting that it has lower capacitive-load handling capability. The LT1113 is identified as having 4.5 nV/√Hz voltage noise, emphasizing that different precision JFET amplifiers optimize for different noise, speed, and load-drive combinations.
Typical applications include precision instrumentation, low-leakage sensor interfaces, audio and measurement buffers, active filtering, and gain stages driving substantial external capacitance. Because exact noise, gain-bandwidth, slew-rate, supply-current, and temperature-range figures were not supplied in the verified excerpts, designers should confirm those values in the manufacturer datasheet before final sizing.
When using the LT1457S8, place the amplifier close to the source and load being conditioned, verify stability with the actual source and load impedances, and check the positive and negative supply rails against the ±20 V maximum cited by the distributor. This page combines verified manufacturer characteristics, distributor package data, ordering information, and application guidance while clearly identifying parameters that still require datasheet confirmation.
Bộ thay thế dễ dàng lắp đặt cho LT1457S8 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
LT1457S8#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LT1457S8 Tỷ lệ tối đa & tính chất điện
| Amplifier Type | Dual precision JFET-input operational amplifier |
| Number of Circuits | 2 circuits |
| Input Offset Voltage | 220 µV in plastic and surface-mount packages |
| Input Bias Current | 50 pA at 70°C |
| Input Offset Current | 20 pA at 70°C |
| Channel Separation | 130 dB |
| Maximum Supply Voltage | ±20 V |
| Capacitive Load Capability | Optimized for large capacitive loads |
| Input Stage Technology | JFET |
| Package Type | 8-pin SOIC |
| Package Height | 1.5 mm maximum |
| Package Width | 3.99 mm maximum |
| Package Length | 5 mm maximum |
| Kiểu lắp đặt | Surface mount |
Hướng dẫn cấu hình chân LT1457S8 5 mm maximum
Cấu hình chân cho LT1457S8 (5 mm maximum gói). Thành phần số hiệu này có chân đầu vào, đầu ra và nguồn cung cấp. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết cấu hình chân bù, bù trừ và chân kích hoạt. Hoàn hảo cho điều kiện tín hiệu và mạch khuếch đại.
Không có dữ liệu chân cụ thể sẵn có cho LT1457S8.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
LT1457S8 phù hợp cho 6 Áp dụngs: Precision Instrumentation Signal Conditioning, High-Impedance Sensor Buffering, Low-Frequency Active Filters, Audio and Low-Noise Buffer Stages, Capacitive Sensor Readout, Industrial Control and Data Acquisition.
Precision Instrumentation Signal Conditioning
The LT1457S8 is well suited to precision instrumentation because its JFET input stage limits input bias current to 50 pA at 70°C and input offset current to 20 pA at 70°C. This reduces loading errors when the source impedance is high, while the verified 220 µV offset voltage supports DC accuracy. Each channel can buffer a sensor, amplifier a differential signal, or drive a subsequent measurement stage. The main design consideration is capacitive-load stability: the Analog Devices LT1457 manufacturer datasheet identifies large-capacitive-load handling as a core advantage, so output routing should be kept compact and tested with the intended load. Supply voltages must remain within the distributor-cited maximum of ±20 V.
Được đề xuất
High-Impedance Sensor Buffering
The LT1457S8 can buffer high-impedance sensors without imposing the larger input currents associated with conventional bipolar-input op amps. The verified 50 pA input bias current at 70°C and 20 pA input offset current at 70°C are particularly useful for electrochemical sensors, photodetectors, and high-resistance probes. The 220 µV input offset specification provides a defined starting point for DC error analysis, although the complete input-voltage, common-mode, and temperature curves remain necessary for a final error budget. Use a nearby input-bias network and guard routing where leakage from board contamination could dominate, and confirm stable operation with the sensor cable and any added protection capacitance.
Được đề xuất
Low-Frequency Active Filters
The LT1457S8 is suitable for precision active filters where low input bias current, modest offset voltage, and good channel separation are valuable. Its dual-channel architecture can implement matched two-pole signal-processing sections or separate filter channels for measurement systems. The verified 130 dB channel separation provides a strong basis for reducing signal-path crosstalk between the two amplifiers. Designers should not infer a specific filter bandwidth from this value alone: the manufacturer datasheet values for gain-bandwidth product, slew rate, and open-loop response were not included in the supplied data and must be checked. Place filter components close to the device and validate transient performance when driving long cables or external reactive loads.
Được đề xuất
Audio and Low-Noise Buffer Stages
The LT1457S8 can serve as a precision buffer or gain stage in low-frequency audio and measurement circuitry when input leakage and DC offset are more important than maximum bandwidth. The verified 220 µV offset voltage provides a documented precision baseline, while the JFET input stage exhibits low bias current. The Analog Devices manufacturer datasheet does not expose the LT1457 voltage-noise density in the supplied excerpts, so it should not be compared directly with the stated 4.5 nV/√Hz LT1113 figure without further data. Confirm the actual noise spectrum, output drive capability, and load impedance before positioning the amplifier in a demanding audio output stage.
Được đề xuất
Capacitive Sensor Readout
The LT1457S8's large-capacitive-load optimization makes it useful in capacitive sensor readout circuits where the sensing node, cable, or input network presents a substantial capacitive load to the amplifier. The manufacturer positions this characteristic as the key reason to prefer the LT1457 over the approximately three-times-faster LT1057. In practice, use short traces, a defined return path, and careful grounding so that added board and cable capacitance does not degrade settling behavior. The verified ±20 V maximum voltage constrains the allowable supply amplitude, while stability under the final load, cable length, and environmental conditions must be confirmed experimentally because those details are not included in the supplied excerpts.
Được đề xuất
Industrial Control and Data Acquisition
The LT1457S8 can condition low-level industrial signals where low bias current helps preserve sensor information and 130 dB channel separation supports isolated measurement channels within one dual package. It is especially relevant when the source presents high impedance or the downstream stage includes significant capacitance. The 8-pin SOIC construction supports compact surface-mount assemblies, while the distributor-cited package dimensions of 5 mm length, 3.99 mm width, and 1.5 mm maximum height guide layout planning. Industrial protection networks, transient events, and temperature ranges were not verified in the supplied data, so the circuit must use suitable external protection and the manufacturer limits must be checked before deployment.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LT1457S8 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | LT1457S8#PBF |
|---|---|---|
| Package | 8-pin SOIC | 8-pin SOIC - same |
| Brand | Analog Devices | Analog Devices |
| Amplifier Configuration | Dual | Dual |
| Input Stage | JFET | JFET |
| Input Offset Voltage | 220 µV | 220 µV |
| Input Bias Current | 50 pA at 70°C | 50 pA at 70°C |
| Input Offset Current | 20 pA at 70°C | 20 pA at 70°C |
| Channel Separation | 130 dB | 130 dB |
| Maximum Voltage | ±20 V | ±20 V |
Bảo phân biệt quan trọng
- Large-capacitive-load optimization (vsLT1057)
- Low-bias-current precision input stage (vsLT1457S8#PBF)
- High channel separation in a dual package (vsLT1457S8#PBF)
Ghi chú thiết kế
Do not treat the LT1057 or LT1113 as automatic drop-in replacements merely because they are related dual JFET-input amplifiers. The Analog Devices manufacturer datasheet says the LT1057 is approximately three times faster but has significantly lower capacitive-load handling capability, while the LT1113 is distinguished by 4.5 nV/√Hz voltage noise. These are different optimization points. For a board-level substitution, verify the 8-pin SOIC pinout, supply limits, offset, bias current, stability, and intended load before approving the change.
Keep the LT1457S8 close to the high-impedance source and keep input traces short, guarded where practical, and separated from noisy switching paths. Because the verified input bias current is 50 pA at 70°C, PCB contamination, connector leakage, and flux residue can become more important than the nominal device error in high-impedance designs. A clean board and suitable guarding strategy help prevent unintended current from flowing through the source impedance and creating an input-offset error.
Validate stability with the complete output network rather than an unloaded bench amplifier. The LT1457 is optimized for large capacitive loads, but real capacitance also depends on cable length, connector construction, input filtering, and device parasitics. Use short output routing, a solid ground return, and the manufacturer's recommended compensation or isolation methods where necessary. Verify settling with a capacitive load close to the worst-case condition rather than relying only on small-signal simulation.
The distributor data identifies ±20 V as the maximum voltage for this device. Confirm whether that rating refers to total supply span or individual rail limits by consulting the official datasheet before applying it to a dual supply. Keep the total supply voltage within the manufacturer limit, account for input common-mode range at each output level, and avoid allowing transient rail excursions to exceed the device limits even if the laboratory supply itself is correctly adjusted.
Thông tin tuân thủ
The verified excerpts did not explicitly state the target's RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. The related LT1457S8#PBF ordering code appears in the source data, but no compliance claim was inferred from its suffix.