LT1885IS - Quad Precision Op Amp | Analog Devices
MPN： LT1885IS ✓ 啟用中LT1885IS 概覽
An operational amplifier, or op amp, is a high-gain differential amplifier used to amplify, buffer, filter, or control voltages. The LT1885 belongs to the precision operational-amplifier hierarchy, where input offset, input bias current, output swing, noise, and stability determine suitability for measurement systems. Its four amplifiers share one package while providing independent signal paths, reducing component count in multi-channel designs.
The LT1885 family is designed for precision applications that benefit from rail-to-rail output operation. Rail-to-rail output allows the amplifier output to approach the available supply rails more closely than a conventional output stage, which can improve dynamic range in low-voltage systems. Picoamp-class input performance is particularly useful when measuring high-impedance sources because the amplifier contributes less input bias current to the measured node.
According to the Analog Devices product information, the LT1884 and LT1885 op amps provide high-accuracy input performance while maintaining rail-to-rail output swing and faster response than other precision amplifiers. Input offset voltage is trimmed to less than 50 µV, supporting accurate conditioning of small differential signals. The LT1885IS contains four amplifiers, while the related LT1884 family is associated with dual-channel configurations.
Typical uses include precision sensor interfaces, low-current measurement stages, current-to-voltage conversion, signal buffering, and multi-axis measurement systems. The four-channel organization is especially useful when four sensors require similar conditioning electronics or when symmetric analog channels are needed in an industrial, medical-instrumentation, or test-and-measurement system.
Designers should verify supply voltage, input common-mode range, output swing under load, noise, gain-bandwidth product, and stability requirements against the manufacturer datasheet for the selected ordering code. Decoupling capacitors should be placed close to the supply pins, and sensitive high-impedance nodes should be protected from leakage, contamination, and electrostatic discharge.
This product page organizes the LT1885IS family information with practical design considerations, qualified same-family alternatives, package details, and application guidance to support component selection and PCB planning.
直接替換替代品，適用於 LT1885IS — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LT1885IS （相同外形與佔位） — 差異在於 Amplifier Type, Input Bias Current Class, Input Offset Voltage, Mounting Type, Package.
LT1885CS
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LT1885MS
✅ 直接替換 ⚠️ 規格未經驗證📋 參考替代品（不在目錄中）
LT1885IS 最大額定值與電氣特性
| Number of Amplifiers | 4 circuits |
| Amplifier Type | Precision operational amplifier |
| Output Topology | Rail-to-rail output |
| Input Bias Current Class | Picoamp-class input |
| Input Offset Voltage | <50 µV |
| 封裝 | 14-pin SO small-outline integrated circuit |
| 安裝類型 | Surface-mount |
LT1885IS 14-pin so small-outline integrated circuit 腳位配置指南
LT1885IS（14-pin so small-outline integrated circuit 封裝）的腳位配置。 此類比元件具有輸入、輸出與電源腳位。偏移歸零、補償與致能腳位配置請參閱製造商資料表。適用於訊號調理與放大器電路。
無詳細腳位定義資料： LT1885IS.
請參閱 資料表 以查看完整腳位配置。
典型應用
LT1885IS 適用於 6 應用s: Precision Sensor Signal Conditioning, Multiaxis Inertial Measurement, Current-to-Voltage Conversion, Industrial Process Measurement, Medical Instrument Front Ends, Precision Test and Measurement.
Precision Sensor Signal Conditioning
The LT1885IS is well suited to four-channel sensor conditioning because it combines picoamp-class input characteristics with input offset voltage trimmed below 50 µV. Its low input bias current helps reduce measurement error when connected to high-impedance sources such as strain gauges, chemical sensors, or photodiode networks. The rail-to-rail output stage can also improve usable signal range in low-voltage acquisition systems. Place each channel close to its source, guard sensitive inputs against contamination and leakage, and verify the common-mode range against the sensor operating voltage before finalizing the interface.
推薦
Multiaxis Inertial Measurement
Four independent amplifier channels make the LT1885IS a practical choice for conditioning the outputs of a multiaxis accelerometer, gyroscope, or magnetic sensor assembly. Picoamp-class input behavior reduces disturbance of high-impedance sensor nodes, while offset below 50 µV supports accurate low-level signal amplification. Rail-to-rail output helps retain signal swing in compact systems operating from restricted voltage rails. Keep each amplifier's high-impedance input path short, use a quiet reference and supply arrangement, and verify whether the sensor requires differential, single-ended, or filtered amplification.
推薦
Current-to-Voltage Conversion
The LT1885IS can implement precision transimpedance stages for photodiodes, optical receivers, and current-output sensors. Picoamp-class input current is important when the feedback resistor creates a high effective input impedance, while the trimmed offset voltage below 50 µV helps reduce output-referred error. Four channels allow several detector or sensor outputs to be converted concurrently. Pay particular attention to input capacitance and stability, use the manufacturer-recommended feedback network, and keep the photodiode node away from high-speed digital and switching traces.
推薦
Industrial Process Measurement
The LT1885IS supports industrial process-measurement front ends that combine low-level sensing with compact four-channel instrumentation. Picoamp-class input behavior is advantageous for resistive bridges and high-impedance probes, and the four-circuit package can condition multiple sensor channels with consistent architecture. Rail-to-rail output supports low-voltage system signal ranges. Confirm the industrial temperature requirement for the chosen ordering code, provide input protection appropriate for the measured source, and isolate analog paths from motor, relay, and switching-converter currents.
推薦
Medical Instrument Front Ends
The LT1885IS is suitable for low-level medical-instrument signal paths where four precision channels and low input bias current can simplify analog conditioning. The family is identified as having picoamp input characteristics, input offset voltage trimmed below 50 µV, and rail-to-rail output. These properties can benefit current-based sensors, bridge-derived measurements, and small biopotential or diagnostic signals. Validate patient protection, isolation, leakage, noise, and applicable medical requirements separately; the amplifier grade alone does not establish compliance for a finished medical instrument.
推薦
Precision Test and Measurement
Four precision amplifier channels in one package are useful in programmable instruments, source-measurement front ends, and general-purpose test platforms. Picoamp-class input performance can reduce loading on high-impedance probes, while offset below 50 µV supports accurate small-signal measurements. Rail-to-rail output provides flexibility when the instrument operates near its supply rails. Engineers should still verify input noise, gain-bandwidth product, settling behavior, and common-mode limits against the actual measurement bandwidth and required accuracy.
推薦
推薦產品摘要
工程參考資料，適用於 LT1885IS — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LT1885CS | LT1885MS |
|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Package | 14-pin SO small-outline integrated circuit | 14-pin SO small-outline integrated circuit | 14-pin SO small-outline integrated circuit |
| Number of Amplifiers | 4 circuits | 4 circuits | 4 circuits |
| Output Topology | Rail-to-rail output | Rail-to-rail output | Rail-to-rail output |
| Input Bias Current Class | Picoamp-class input | Picoamp-class input | Picoamp-class input |
| Input Offset Voltage | <50 µV | <50 µV | <50 µV |
| Upper Operating Temperature | Approximately +85 °C | Approximately +70 °C | Approximately +125 °C |
| Lower Operating Temperature | Approximately -40 °C | Approximately 0 °C | Approximately -40 °C |
主要差異化特點
- Four precision amplifier channels in one package (對比LT1885CS)
- Industrial temperature coverage (對比LT1885CS)
- Extended-temperature option remains pin compatible (對比LT1885MS)
設計說明
Route each sensitive LT1885IS input directly to its source and keep the surrounding area free of long leakage-prone traces. High-impedance nodes can collect contamination and PCB-surface leakage, so use a suitable guard where practical. Maintain separation between neighboring channels when they carry high-gain signals, and place the required bypass capacitors close to the supply pins to limit supply ripple inside the amplifier package.
Do not select the LT1885IS solely from its picoamp input class and sub-50 µV offset rating. Verify the supply range, input common-mode limits, output swing under the intended load, gain-bandwidth product, slew rate, noise, and stability for the actual operating condition. A precision amplifier can still produce large errors when the signal exceeds its common-mode range or when the feedback network creates excessive noise gain.
For transimpedance and high-impedance sensor applications, assess the total input capacitance, including sensor, PCB, guard structures, and amplifier input capacitance. Use the manufacturer's recommended feedback resistor and compensation approach, and keep the input node physically small. If the required bandwidth approaches the amplifier's capability, evaluate settling behavior and stability across temperature rather than relying only on typical response data.
Decouple the LT1885IS supply pins with the capacitance and placement specified in the manufacturer datasheet. Because the device contains four amplifier channels, simultaneous full-bandwidth operation can increase supply current and board-level heat dissipation. Provide adequate copper area and verify worst-case output swing, load current, ambient temperature, and power consumption across the four channels rather than estimating from one channel.
合規資訊
The LT1885 family is listed as production by Analog Devices. Explicit RoHS, REACH, lead-free, halogen-free, and conflict-minerals declarations are not stated for this ordering code in the referenced manufacturer information.
