LT1805CS - 85MHz Quad Rail-to-Rail Op Amp | Analog Devices
Артикул: LT1805CS ✓ АктивенLT1805CS Обзор
An operational amplifier is an analog integrated circuit that amplifies the voltage difference between its inverting and non-inverting inputs. The LT1805 belongs to the operational-amplifier hierarchy, where rail-to-rail input and output capability allows operation close to the supply rails. This makes the device useful in signal chains requiring high speed, wide common-mode range, and flexible output swing.
Principal features include an 85 MHz gain-bandwidth product, a 100 V/µs slew rate, a 120 MHz −3 dB frequency at unity gain, and 4.2 nV/√Hz broadband input voltage noise. The quad configuration integrates four amplifiers into one 14-pin SOIC, allowing multiple gain stages or differential channels to share a compact footprint while preserving consistent device characteristics.
The LT1805 family is designed for low-power, high-speed analog signal processing. Rail-to-rail input operation extends the usable input range toward the positive and negative supply rails, while rail-to-rail output provides improved output swing for downstream circuits. Its high slew rate supports rapid signal transitions, although stability, load capability, and output-current limits must be evaluated against the intended operating conditions.
Typical applications include low-level signal conditioning, instrumentation front ends, active filtering, data-acquisition channels, sensor amplification, and high-speed buffer stages. The quad organization is particularly useful when a system requires several amplifiers, such as instrumentation amplifiers, multichannel sensor interfaces, or gain stages distributed across an analog board.
Design with the LT1805CS by confirming supply voltage, input and output common-mode limits, capacitive-load stability, and noise performance for every signal range. Place bypass capacitors close to the supply pins, keep sensitive input traces short, and account for the PCB’s ground return when evaluating noise. The manufacturer datasheet should guide the final compensation, grounding, and application-circuit choices.
This product page combines the family-level operating characteristics, package information, application guidance, and sourcing workflow for the LT1805CS. It also distinguishes the exact orderable variants from broader LT1805 options so engineers can identify whether a proposed replacement preserves the required amplifier count, package, and electrical behavior.
Аналоги без доработки для LT1805CS — тот же корпус, pin-to-pin совместимость. Компоненты в других корпусах, требующие переработки PCB, исключены.
LT1805CS#PBF
✅ Прямая замена📋 Справочный аналог (нет в каталоге)
LT1805CS Максимальные параметры и электрические характеристики
| Amplifier Type | General-purpose operational amplifier |
| Number of Amplifiers | 4 amplifiers |
| Gain Bandwidth Product | 85 MHz |
| Unity-Gain −3 dB Frequency | 120 MHz |
| Slew Rate | 100 V/µs |
| Ток покоя | 1 mA maximum |
| Input Common-Mode Range | Rail-to-rail |
| Output Swing | Rail-to-rail |
| Broadband Input Voltage Noise | 4.2 nV/√Hz |
| Корпус | 14-pin SOIC |
| Тип монтажа | Surface mount |
| Product Lifecycle | Production |
Руководство по цоколевке LT1805CS в корпусе 14-pin soic
Цоколевка для LT1805CS (корпус 14-pin soic). Этот аналоговый компонент имеет выводы входа, выхода и питания. Обратитесь к техническому описанию производителя для конфигураций выводов балансировки нуля, коррекции и разрешения. Идеально подходит для схем обработки сигналов и усилителей.
Нет подробных данных о распиновке для LT1805CS.
Обратитесь к даташиту для полной конфигурации выводов.
Типичное применение
LT1805CS подходит для 6 применениеs: Multichannel Sensor Signal Conditioning, Precision Instrumentation Amplifier, Active Audio Signal Conditioning, Data Acquisition Analog Front End, High-Speed Buffering and Line Driving, Industrial Control Signal Conditioning.
Multichannel Sensor Signal Conditioning
The LT1805CS fits multichannel sensor front ends that require four amplifiers but operate below the device’s 85 MHz gain-bandwidth limit. Its rail-to-rail input capability supports signal ranges near the supply rails, while 4.2 nV/√Hz broadband input noise helps preserve weak sensor signals. Place the quad device near the sensor inputs, use short grounded input routes, and select resistor values that keep noise gain and signal bandwidth within the closed-loop response required by the sensor.
Рекомендуется
Precision Instrumentation Amplifier
The LT1805CS can form the core of a four-amplifier instrumentation stage when the required signal bandwidth is substantially below 85 MHz. Rail-to-rail input and output operation allows the stage to operate near the available supply range, and the 100 V/µs slew rate supports rapid signal changes. Check input common-mode limits for every sensor range and evaluate noise gain carefully, because the four amplifier channels must preserve matching and stability across the complete input range.
Рекомендуется
Active Audio Signal Conditioning
The LT1805CS is appropriate for active audio filtering or preamplifier stages requiring greater bandwidth than low-speed audio amplifiers while remaining within its 85 MHz gain-bandwidth capability. Rail-to-rail output operation helps preserve signal swing, and the 4.2 nV/√Hz input noise specification is useful for low-level audio paths. The actual noise contribution depends on source resistance, closed-loop gain, bandwidth, and the selected feedback network, so the complete signal path should be evaluated rather than the device alone.
Рекомендуется
Data Acquisition Analog Front End
The LT1805CS can provide differential amplification, gain, and buffering within a high-speed data-acquisition front end. Its 120 MHz −3 dB unity-gain frequency and 100 V/µs slew rate offer headroom for signals above audio-band frequencies, while four amplifiers allow several conversion channels to share one package. Establish the required settling accuracy, bandwidth, output-current capability, and driving distance before selection, and verify stable operation with the actual converter and sampling network.
Рекомендуется
High-Speed Buffering and Line Driving
The LT1805CS is suitable for intermediate buffer stages in fast analog systems because its 100 V/µs slew rate supports rapid voltage transitions and its rail-to-rail output improves available output swing. Four channels can buffer multiple control, sensing, or drive nodes while retaining a common device type. Buffer stability depends on load capacitance, gain, output-current demand, and trace length, so test the intended load and keep feedback routes short and physically separated from sensitive inputs.
Рекомендуется
Industrial Control Signal Conditioning
The LT1805CS supports industrial control modules that condition sensor or command signals with a compact four-channel amplifier arrangement. Its low 1 mA maximum quiescent current can help manage power demand, while 85 MHz bandwidth and rail-to-rail operation provide flexibility for low-voltage control systems. The design must still satisfy the relevant industrial temperature range, isolation strategy, surge exposure, grounding arrangement, and functional-safety requirements; these system conditions are separate from the amplifier’s core electrical ratings.
Рекомендуется
Сводка рекомендуемых товаров
Справочные инженерные данные для LT1805CS — сравнение, рекомендации по проектированию и информация о соответствии.
Руководство по выбору
Сравнение с аналогами
| Параметр | Этот товар | LT1805CS#PBF |
|---|---|---|
| Package | 14-pin SOIC | 14-pin SOIC |
| Brand | Analog Devices | Analog Devices |
| Number of Amplifiers | 4 | 4 |
| Gain Bandwidth Product | 85 MHz | 85 MHz |
| Slew Rate | 100 V/µs | 100 V/µs |
| Input Common-Mode Range | Rail-to-rail | Rail-to-rail |
| Output Swing | Rail-to-rail | Rail-to-rail |
| Broadband Input Voltage Noise | 4.2 nV/√Hz | 4.2 nV/√Hz |
| Quiescent Current | 1 mA maximum | 1 mA maximum |
Ключевые отличия
- Four high-speed amplifiers in one package (против LT1805CS#PBF)
- High bandwidth for a low-power quad amplifier (против LT1805CS#PBF)
- Rail-to-rail signal-range capability (против LT1805CS#PBF)
Заметки по проектированию
Place the supply bypass capacitors immediately beside the LT1805CS power and ground pins, and use a low-impedance ground plane for the high-frequency return path. Keep amplifier inputs away from supply-current edges and switching-node copper. Because the device offers an 85 MHz gain-bandwidth product and 100 V/µs slew rate, long unprotected traces and inductive branches can create ringing even when the nominal application bandwidth is much lower.
Keep feedback components and their associated traces compact, and use the lowest practical feedback resistance to limit amplifier-generated noise and susceptibility to parasitic capacitance. Do not assume unity-gain stability for every load condition; evaluate capacitive loading and gain against the manufacturer guidance. For instrumentation and sensor channels, preserve symmetry between differential inputs so the quad device’s common-mode conversion does not degrade the measurement.
Rail-to-rail input does not mean every input and output combination is unrestricted. Confirm the valid common-mode and output ranges for the selected supply voltage, including behavior near the rails. Also verify that the 4.2 nV/√Hz noise figure is appropriate for the source impedance and target bandwidth, and do not substitute a different LT180x amplifier merely because it also uses a 14-pin SO package.
Budget the device’s supply consumption around the 1 mA maximum quiescent-current specification, then add output-current demand, switching activity, and bypass-capacitor losses. The dissipated power increases with supply voltage and output current. Because this is a linear operational amplifier rather than a switching regulator, verify thermal headroom in the enclosure and provide PCB copper for heat spreading when continuous loading is expected.
Информация о соответствии
The LT1805CS#PBF order code identifies a lead-free configuration, but no explicit RoHS, REACH, halogen-free, or conflict-minerals declaration was identified for the LT1805CS family. AEC-Q100 is not applicable to this general-purpose operational amplifier.