LT1491CS - Quad 44V Micropower R-R Op Amp | Analog Devices
MPN: LT1491CS ✗ סוף ייצורLT1491CS סקירה
An operational amplifier is an analog signal-processing IC that amplifies the voltage difference between its non-inverting and inverting inputs. The LT1491CS belongs to the micropower operational-amplifier hierarchy, where low quiescent current, rail-to-rail signal handling, and wide supply-voltage tolerance are the defining attributes. These characteristics place it within precision analog and general-purpose amplifier ICs used when low power and flexible supply operation are more important than high bandwidth.
The four integrated amplifiers provide rail-to-rail input and output behavior, allowing signals to approach the supply rails without requiring separate input and output biasing. Maximum quiescent current is specified at 50 µA per amplifier, while the Analog Devices product overview describes 40 µA per amplifier under its stated operating conditions. Reverse-supply protection prevents current flow when supply polarity is reversed, adding robustness in battery-powered and field-wired equipment.
The LT1491CS supports a wide total supply range from 2 V to 44 V. This allows one amplifier family to cover single-supply systems near 3 V, conventional 5 V logic rails, split ±15 V analog systems, and higher industrial supply combinations. The 14-pin SOIC package provides four amplifiers in a standard surface-mount footprint, reducing board area compared with four separate single-amplifier packages.
Typical uses include low-power sensor signal conditioning, battery-operated instrumentation, portable measurement equipment, industrial process controls, and buffered analog inputs. The rail-to-rail inputs are useful when operating from low-voltage supplies because the usable input range can extend toward either supply rail. The output stage is also rail-to-rail, helping preserve dynamic range in compact, low-voltage systems where headroom is limited.
Designers should verify input common-mode range, output swing, offset, bandwidth, noise, settling behavior, and stability for the intended supply and load before treating the amplifier as a universal substitute. Decoupling capacitors should be placed close to the supply pins, and unused amplifier inputs should be biased appropriately. Because the manufacturer marks LT1491 as not recommended for new designs, new production designs should generally evaluate an active current-generation alternative unless the legacy device is specifically required.
This product page combines the verified Analog Devices product information, distributor availability information, lifecycle status, package details, and same-family replacement candidates with practical selection guidance. It distinguishes confirmed manufacturer facts from unavailable electrical values and avoids presenting unverified specifications or cross-brand substitutions as drop-in replacements.
חלופות תחליף ישיר עבור LT1491CS — אותו מארז, תואם פין-לפין. חלקים במארז שונה הדורשים עיבוד מחדש של ה-PCB אינם נכללים.
LT1491IS#PBF
✅ Drop-In📋 חלופה להתייחסות (לא בקטלוג)
LT1491ACS#PBF
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
LT1491HCS#PBF
✅ Drop-In ⚠️ מפרטים לא מאומתים📋 חלופה להתייחסות (לא בקטלוג)
LT1491CS דירוגים מרביים ומאפיינים חשמליים
| Number of Amplifiers | 4 amplifiers |
| Product Type | Micropower operational amplifier |
| Total Supply Voltage Range | 2 V to 44 V |
| זרם מנוחה | 40 µA per amplifier |
| Maximum Quiescent Current | 50 µA per amplifier |
| Input Common-Mode Range | Rail-to-rail input |
| Output Swing | Rail-to-rail output |
| Reverse Supply Protection | Supported; no current for reverse supply up to 18 V |
| Specified Supply Configurations | 3 V, 5 V, and ±15 V |
| מארז | 14-pin SOIC |
| סוג הרכבה | Surface mount |
| Product Classification | Standard general-purpose amplifier |
| Manufacturer Lifecycle Recommendation | Not recommended for new designs |
| Price Starting From | $5.15 |
תצורת פינים של LT1491CS
| פין 1 | OUTA — Amplifier A output |
| פין 2 | -INA — Amplifier A inverting input |
| פין 3 | +INA — Amplifier A non-inverting input |
| פין 4 | V- — Negative supply or ground |
| פין 5 | +INB — Amplifier B non-inverting input |
| פין 6 | -INB — Amplifier B inverting input |
| פין 7 | OUTB — Amplifier B output |
| פין 8 | OUTC — Amplifier C output |
| פין 9 | -INC — Amplifier C inverting input |
| פין 10 | +INC — Amplifier C non-inverting input |
| פין 11 | V+ — Positive supply |
| פין 12 | +IND — Amplifier D non-inverting input |
| פין 13 | -IND — Amplifier D inverting input |
| פין 14 | OUTD — Amplifier D output |
יישומים טיפוסיים
LT1491CS מתאים עבור 6 יישוםs: Battery-Powered Sensor Signal Conditioning, Portable Instrumentation, Industrial Process Measurement, Low-Voltage Data Acquisition, Audio and Low-Level Analog Buffers, Power-Supply Monitoring and Control.
Battery-Powered Sensor Signal Conditioning
The LT1491CS fits battery-powered sensor interfaces because each amplifier draws approximately 40 µA of quiescent current, allowing four channels to operate from one package. Its rail-to-rail input capability is useful when the conditioned sensor signal approaches the limits of a low-voltage supply, and rail-to-rail output operation preserves available signal range. The device accepts total supplies from 2 V to 44 V, although designers should verify the actual sensor excitation level, input bias current, output load, and the specific operating-temperature grade before production release.
מומלץ
Portable Instrumentation
The LT1491CS is useful in portable instrumentation where four measurement channels must fit on a compact circuit board without continuously loading the battery. Its quad organization replaces four separate low-power amplifier packages, while the 40 µA per-amplifier quiescent current limits standby demand. The broad 2 V to 44 V total supply range supports legacy instrument architectures ranging from low-voltage battery rails to split analog supplies. Engineers must still account for offset, input bias current, noise, output drive, and accuracy over the required measurement range.
מומלץ
Industrial Process Measurement
The LT1491CS can support low-power industrial process-measurement front ends that acquire several low-level sensor signals. Four rail-to-rail amplifier channels provide flexible conditioning for current loops, resistive sensors, and buffered inputs, while the ability to operate from a 2 V to 44 V total supply accommodates legacy industrial signal chains. The low 40 µA per-amplifier quiescent current is valuable where many measurement channels must share limited power. Protection, isolation, surge immunity, calibration accuracy, and the required industrial temperature range must be evaluated separately from amplifier specifications.
מומלץ
Low-Voltage Data Acquisition
The LT1491CS fits legacy low-voltage data-acquisition systems requiring four conditioned analog channels in a single SOIC package. Rail-to-rail inputs help preserve sensor information when the available supply headroom is small, and the 2 V minimum total supply supports compact systems operating near 3 V. Its 40 µA per-amplifier quiescent current also limits the overhead introduced by four amplifier channels. For high-resolution converters, however, the designer must verify amplifier noise, settling time, offset, and settling behavior against the acquisition bandwidth.
מומלץ
Audio and Low-Level Analog Buffers
The LT1491CS can buffer low-level audio or communications signals when low quiescent current is more important than wideband performance. Rail-to-rail input and output operation reduce signal-range restrictions in compact single-supply equipment, while the quad package provides four buffered channels for stereo or multi-channel paths. The manufacturer data confirms the micropower and rail-to-rail characteristics, but noise, bandwidth, slew rate, channel separation, and output-load capability were not supplied and must be checked before using this legacy amplifier in a new audio design.
מומלץ
Power-Supply Monitoring and Control
The LT1491CS can implement low-power monitoring functions such as rail sensing, threshold comparison, and control-loop amplification where four channels are useful. Its 2 V to 44 V total supply range permits operation from low-voltage control rails as well as higher industrial rails, and reverse-supply protection adds tolerance to reverse polarity up to 18 V. Because the four amplifiers share one package and supply, common-mode limits, output behavior, and thermal conditions apply to every channel. The design should also include proper input clamping and verify behavior during supply transitions.
מומלץ
סיכום מוצרים מומלצים
נתוני עזר הנדסיים עבור LT1491CS — השוואה, הנחיות תכנון ומידע על תאימות.
מדריך בחירה
השוואה עם חלופות
| פרמטר | מוצר זה | LT1491IS#PBF | LT1491ACS#PBF | LT1491HCS#PBF |
|---|---|---|---|---|
| Package | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC | 14-pin SOIC |
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Number of Amplifiers | 4 | 4 | 4 | 4 |
| Total Supply Voltage Range | 2 V to 44 V | 2 V to 44 V | 2 V to 44 V | 2 V to 44 V |
| Quiescent Current per Amplifier | 40 µA typical; 50 µA maximum | 40 µA typical; 50 µA maximum | 40 µA typical; 50 µA maximum | 40 µA typical; 50 µA maximum |
| Input Common-Mode Range | Rail-to-rail input | Rail-to-rail input | Rail-to-rail input | Rail-to-rail input |
| Output Swing | Rail-to-rail output | Rail-to-rail output | Rail-to-rail output | Rail-to-rail output |
| Reverse Supply Protection | Yes; no reverse current up to 18 V | Yes; no reverse current up to 18 V | Yes; no reverse current up to 18 V | Yes; no reverse current up to 18 V |
| Specified Supply Configurations | 3 V, 5 V, and ±15 V | 3 V, 5 V, and ±15 V | 3 V, 5 V, and ±15 V | 3 V, 5 V, and ±15 V |
מבדילים עיקריים
- Four micropower amplifier channels in one standard package (לעומתLT1491IS#PBF)
- Broad total supply-voltage coverage (לעומתLT1491ACS#PBF)
- Rail-to-rail input and output in a micropower quad amplifier (לעומתLT1491HCS#PBF)
הערות תכנון
Place the supply bypass capacitor directly between the V+ and V- pins and connect it to a low-impedance ground plane. The four amplifiers share the package supply, so supply transients can affect every channel simultaneously. Account for 40 µA typical or 50 µA maximum quiescent current per amplifier, equivalent to 160 µA typical or 200 µA maximum for the complete device, before adding load-current and transient losses.
Keep input and output routing short, especially for high-impedance sensor nodes. Place input-biasing networks near the associated amplifier pins and avoid sharing narrow high-impedance traces with output-return paths. Although the LT1491CS uses a standard 14-pin SOIC footprint, pin assignment and common-mode behavior must be checked for the selected grade. Always verify the exact pinout against the current manufacturer datasheet before releasing artwork.
Do not interpret reverse-supply protection as permission to exceed the absolute maximum supply rating. The verified family information states that reverse supply up to 18 V draws no current, while normal operation remains limited to a 2 V to 44 V total supply range. Also ensure unused amplifier inputs are tied to a defined common-mode potential rather than left floating. Finally, confirm gain-bandwidth, offset, noise, slew rate, and output-swing requirements from the datasheet before using this NRND device in a new design.
מידע על תאימות
The supplied verified data identifies the lead-free LT1491CS#PBF ordering code but does not provide explicit RoHS, REACH, AEC-Q100, halogen-free, or conflict-minerals statements. Compliance is therefore recorded as unknown rather than inferred.