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Analog Devices Inc. LT1491ACDHC#PBF
- Part No.:
- LT1491ACDHC#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 16-WFDFN Exposed Pad
- Datasheet:
-
LT1491ACDHC#PBF.pdf
- Description:
- IC OPAMP GP 4 CIRCUIT 16DFN
- Quantity:
- Payment:
- Shipping:
Inventory:125
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Product details
Overview
LT1491ACDHC#PBF from Analog Devices (formerly Linear Technology) is a quad micropower rail-to-rail input/output operational amplifier optimized for battery- and solar-powered systems. It features 500 μV max input offset voltage, 40 μA per amplifier quiescent current, 2 V to 44 V total supply range, ±20 mA output drive, and Over-The-Top® input operation extending 44 V above V–-enabling direct sensing in high-side current monitoring applications.
For engineers reviewing the LT1491ACDHC#PBF datasheet, LT1491ACDHC#PBF pinout, LT1491ACDHC#PBF application, or LT1491ACDHC#PBF equivalent, key selection criteria include micropower operation under 2 V supplies, reverse-battery protection up to 18 V, rail-to-rail I/O swing with 10 mV min output saturation, and compatibility with capacitive loads up to 10,000 pF using optional 0.22 μF/150 Ω compensation.
Technical Context
The LT1491ACDHC#PBF employs dual-input-stage architecture (NPN + PNP) enabling true Over-The-Top® operation: inputs remain functional and high-impedance even when biased 44 V above V–, independent of V+. Built-in 1 kΩ series resistors and clamping diodes protect inputs against faults down to 15 V below V– without phase reversal.
It delivers 200 kHz gain-bandwidth product and 0.035 V/μs slew rate at ±15 V, with unity-gain stability and internal compensation for ≥200 pF loads. Optional external 0.22 μF capacitor + 150 Ω resistor enables stable driving of up to 10,000 pF-critical for sensor interfaces with long cables or ADC input filtering.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 44 V total - supports single-cell Li-ion (2.7 V), 12 V automotive, and ±15 V industrial rails without level-shifting. |
| Quiescent Current | 40 μA per amplifier - enables multi-year battery life in always-on sensor nodes and portable instrumentation. |
| Input Offset Voltage | 500 μV max (0°C to 70°C) - ensures ≤0.5 mV error in 10-bit precision current-sense amplifiers at 3 V supply. |
| Output Drive | ±20 mA - directly drives 200 Ω loads (e.g., 4–20 mA transmitter output stages) without external buffers. |
| Input Common-Mode Range | Extends 44 V above V– - allows high-side current sensing in 48 V telecom or EV battery packs with no external resistive divider. |
| Capacitive Load Drive | Up to 10,000 pF with 0.22 μF + 150 Ω compensation - supports long traces to remote sensors or EMI-filtered ADC inputs. |
| Reverse Supply Protection | 18 V - survives accidental battery reversal in field-deployed equipment without fuse or external diode. |
Pinout & Package
LT1491ACDHC#PBF is housed in a 16-lead (5 mm × 3 mm) plastic DFN package with exposed metal pad connected to V–. The package supports high thermal performance (θJA = 160°C/W) and compact PCB layout for space-constrained IoT edge nodes.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 2, 3, 4 | OUT A, –IN A, +IN A, V+ | Amplifier A output, inverting input, non-inverting input, and positive supply - standard op-amp configuration for first channel. |
| 5, 6, 7, 8 | +IN B, –IN B, OUT B, NC | Amplifier B non-inverting input, inverting input, output, and no-connect - NC pin isolates B-channel output from adjacent routing. |
| 9, 10, 11, 12 | OUT C, –IN C, +IN C, V– | Amplifier C output, inverting input, non-inverting input, and negative supply - V– shared across all four amplifiers. |
| 13, 14, 15, 16 | +IN D, –IN D, OUT D, NC | Amplifier D non-inverting input, inverting input, output, and no-connect - dual NC pins enable ground plane continuity under package. |
Key Features
| Feature | Design Value |
|---|---|
| Over-The-Top® Input Stage | Enables high-side sensing at 48 V bus while operating from 3.3 V logic supply - eliminates need for isolated power or level translators. |
| Rail-to-Rail Output Swing | Swings within 10 mV of V– and 25 mV of V+ at 5 mA load - maximizes dynamic range in low-voltage ADC front-ends. |
| Micropower + High Output Current | 40 μA quiescent current with ±20 mA drive - resolves traditional trade-off between battery life and actuator/sensor interface capability. |
| Reverse Battery Protection | Draws <1 nA at –18 V supply - prevents system damage and data loss during field maintenance or battery replacement. |
| No Phase Reversal | Output remains monotonic for inputs 15 V below V– or 44 V above V– - ensures safe operation in fault-tolerant motor control feedback paths. |
Applications
| Battery Monitoring | High-Side Current Sensing |
|---|---|
Use Scenario: Real-time state-of-charge estimation in 12 V lead-acid or 48 V LiFePO₄ battery banks for UPS and telecom backup systems. IC Role / Device Role / Timing Role: Quad op-amp configured as differential amplifier (A/B channels), reference buffer (C), and comparator hysteresis generator (D). Use Value: 500 μV offset enables ±1% current measurement accuracy over temperature; 44 V Over-The-Top® input avoids external attenuators on high-voltage strings. | Use Scenario: Precision current measurement in 4–20 mA loop transmitters for industrial process control valves and pressure sensors. IC Role / Device Role / Timing Role: Amplifier A drives 250 Ω load; B/C form Kelvin-sense differential pair; D provides programmable zero-adjust reference. Use Value: ±20 mA output drive eliminates external transistor stage; rail-to-rail swing ensures full 4–20 mA compliance at 3.3 V supply. |
| Solar Charge Controller Feedback | Micropower Active Filter |
Use Scenario: MPPT voltage/current sampling and battery voltage regulation in off-grid solar inverters with 24–48 V PV arrays. IC Role / Device Role / Timing Role: Amplifier A/B condition shunt voltage; C buffers reference; D implements analog PID integrator with 10,000 pF compensation. Use Value: 2 V minimum supply allows operation during low-light conditions; reverse protection prevents damage during panel disconnect events. | Use Scenario: Anti-aliasing and sensor signal conditioning in wireless vibration monitors powered by coin-cell batteries. IC Role / Device Role / Timing Role: Quad topology implements 2-pole Sallen-Key low-pass filter (A/B), 2-pole high-pass (C/D), all sharing common bias network. Use Value: 40 μA per amplifier enables 10-year battery life; 200 kHz GBW supports 10 kHz filter cutoff with <0.1° phase error. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar quad micropower op-amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV2474IDR | Lower supply range (2.7–6 V), 600 μV offset, no Over-The-Top® input - requires level-shifting for >6 V sensing. | Best suited for 3.3 V embedded systems only; cannot replace LT1491ACDHC#PBF in 12–48 V industrial monitoring. | Select when cost-sensitive designs operate strictly below 6 V and do not require high-side sensing. |
| OPA4340UA | Single-supply only (2.7–5 V), 125 μV offset, rail-to-rail I/O - lacks reverse-battery protection and >44 V common-mode capability. | Ideal for precision medical sensors at 3.3 V but unsuitable for automotive or telecom battery monitoring. | Choose for ultra-low-offset needs in low-voltage portable devices where Over-The-Top® and reverse protection are unnecessary. |
Compared with TLV2474IDR and OPA4340UA, the LT1491ACDHC#PBF uniquely combines 2–44 V operation, Over-The-Top® input, reverse-battery survival, and 40 μA quiescent current - making it the only option for robust, wide-range micropower sensing without auxiliary circuitry.
Availability
LT1491ACDHC#PBF is available at Aetrix Electronics and suitable for battery monitoring, high-side current sensing, and solar charge controller applications requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant packaging.
Supply support for LT1491ACDHC#PBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Analog Devices acquired Linear Technology in 2017 and maintains its legacy of precision analog ICs for demanding industrial, automotive, and instrumentation markets.
The LT1491A product line was designed specifically for micropower, high-voltage-sensing applications where rail-to-rail operation, Over-The-Top® input, and reverse-battery resilience are mandatory - targeting battery management, energy harvesting, and harsh-environment sensor interfaces.
FAQ
What is the maximum capacitive load the LT1491ACDHC#PBF can drive without external compensation?
The LT1491ACDHC#PBF is internally compensated to drive ≥200 pF capacitively without oscillation under all load conditions. For loads exceeding 200 pF - such as long PCB traces or EMI filters - a 0.22 μF capacitor in series with a 150 Ω resistor from output to ground extends stable operation up to 10,000 pF. This configuration is validated in the LT1491ACDHC#PBF datasheet Figure 21.
Does the LT1491ACDHC#PBF support true Over-The-Top® operation on a 3 V single supply?
Yes. The LT1491ACDHC#PBF's Over-The-Top® input stage operates with inputs up to 44 V above V– regardless of V+, enabling direct connection to 12 V or 24 V buses while powered from a 3 V microcontroller rail. Input bias current remains <3 μA and offset voltage stays within 700 μV when inputs exceed V+ by 0.3 V, as confirmed in the Simplified Schematic and Applications Information sections.
What is the reverse supply voltage rating of the LT1491ACDHC#PBF, and how does it behave during reverse polarity events?
The LT1491ACDHC#PBF withstands reverse supply voltages up to –18 V, drawing less than 1 nA supply current during the event. This behavior is intrinsic to its internal protection architecture and requires no external components. The device resumes normal operation immediately upon restoration of correct polarity - verified in Absolute Maximum Ratings and Applications Information sections of the datasheet.
Can the LT1491ACDHC#PBF be used in a 4–20 mA transmitter output stage without an external transistor?
Yes. With ±20 mA output drive capability and rail-to-rail swing (within 10 mV of V– and 25 mV of V+ at 5 mA), the LT1491ACDHC#PBF directly sources/sinks full 4–20 mA into a 250 Ω load at 3.3 V or 5 V supply. Its 500 μV max offset ensures ≤0.2% full-scale error in current-loop calibration - eliminating the need for discrete pass transistors in space-constrained designs.
Is the LT1491ACDHC#PBF pin-compatible with other packages in the LT1491A family, such as SO-14 or PDIP-14?
No. The LT1491ACDHC#PBF uses a 16-pin DFN (5 mm × 3 mm) footprint with two no-connect (NC) pins and V– shared across all amplifiers, whereas SO-14 and PDIP-14 variants use 14-pin layouts with dedicated V+ and V– pins per pair and no NC pins. Pin mapping differs fundamentally - e.g., pin 8 is NC in DFN but OUT B in SO-14 - requiring PCB redesign for package interchange.
LT1491ACDHC#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- LT®
- Package/Case:
- 16-WFDFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Amplifier Type:
- General Purpose
- Number of Circuits:
- 4
- Output Type:
- Rail-to-Rail
- Slew Rate:
- 0.06V/µs
- Gain Bandwidth Product:
- 200 kHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 1 nA
- Voltage - Input Offset:
- 285 µV
- Current - Supply:
- 50µA (x4 Channels)
- Current - Output / Channel:
- 25 mA
- Voltage - Supply Span (Min):
- 2 V
- Voltage - Supply Span (Max):
- 44 V
- Operating Temperature:
- 0°C ~ 70°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-DFN (5x3)
LT1491ACDHC#PBF FAQ
1.How can I place an order for LT1491ACDHC#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1491ACDHC#PBF on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for LT1491ACDHC#PBF reliable?
The price and inventory of LT1491ACDHC#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1491ACDHC#PBF is usually 5 days.
3.What payment methods are accepted for LT1491ACDHC#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1491ACDHC#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1491ACDHC#PBF?
LT1491ACDHC#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1491ACDHC#PBF order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for LT1491ACDHC#PBF?
For technical support, including LT1491ACDHC#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1491ACDHC#PBF requirements.
6.How does Aetrix verify that LT1491ACDHC#PBF is sourced from the original manufacturer or authorized distributors?
All LT1491ACDHC#PBF products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that LT1491ACDHC#PBF meets industry standards.
7.What is the process for return or replacement of LT1491ACDHC#PBF?
All LT1491ACDHC#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1491ACDHC#PBF, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The LT1491ACDHC#PBF part is unused and in its original packaging.
Return procedure for LT1491ACDHC#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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