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Analog Devices Inc./Maxim Integrated MAX4491AUA-T
- Part No.:
- MAX4491AUA-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX4491AUA-T.pdf
- Description:
- IC OPAMP GP 2 CIRCUIT 8UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:3,617
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Product details
Overview
MAX4491AUA-T from Maxim Integrated is a single-channel, rail-to-rail input/output CMOS operational amplifier in an 8-pin µMAX package, designed for precision signal conditioning in low-voltage systems. It operates from a single 2.7V to 5.5V supply, delivers 10MHz gain-bandwidth, 10V/µs slew rate, and drives 2kΩ loads to within 55mV of either rail across –40°C to +125°C - ideal for automotive sensor front-ends and battery-powered instrumentation.
For engineers reviewing the MAX4491AUA-T datasheet, MAX4491AUA-T pinout, MAX4491AUA-T application, or MAX4491AUA-T equivalent, key selection criteria include its guaranteed automotive temperature range, capacitive-load stability up to 300pF, ultra-low 50pA input bias current, and rail-to-rail output swing under heavy resistive load - all critical for high-accuracy analog signal chains in space-constrained designs.
Technical Context
The MAX4491AUA-T employs parallel N- and P-channel differential input stages enabling true rail-to-rail common-mode input range (VSS to VDD), with seamless handoff between input pairs near VSS + 1.2V and VDD – 1.2V. Its class-AB push-pull output stage delivers ±50mA short-circuit current and maintains <55mV output swing headroom into 2kΩ at full temperature range.
It achieves unity-gain stability with capacitive loads ≤300pF without external compensation, supported by 60° phase margin and 10dB gain margin at 10MHz. Input capacitance is 5pF, requiring R′ <3kΩ for optimal AC stability in inverting/noninverting configurations per design guidelines.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.7V to 5.5V single supply - supports direct interfacing with Li-ion batteries and 3.3V logic without level shifting. |
| Gain-Bandwidth Product | 10MHz - enables stable closed-loop operation up to ~1MHz with gain ≥10, suitable for anti-aliasing and active filtering. |
| Slew Rate | 10V/µs - ensures faithful reproduction of fast transients (e.g., pulse-width modulated sensor signals) without distortion. |
| Input Bias Current | ±50pA typical - minimizes voltage error in high-impedance sensor interfaces (e.g., thermistors, photodiodes). |
| Output Swing (2kΩ) | VSS + 55mV to VDD – 55mV - preserves dynamic range in single-supply data acquisition with 12-bit+ ADCs. |
| Capacitive Load Drive | Stable with ≤300pF - allows direct driving of ADC input capacitors or long PCB traces without isolation resistor. |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive, industrial motor control, and harsh-environment monitoring. |
| Input Offset Voltage | ±1.5mV max - limits baseline error in precision current-sense amplification and bridge sensor conditioning. |
Pinout & Package
MAX4491AUA-T is housed in an 8-pin µMAX package (3mm × 3mm, 0.8mm height), pin-compatible with industry-standard SO-8 and TSSOP-14 footprints via adapter but physically distinct. The µMAX offers superior thermal performance vs. SOT23-8 while maintaining board-area efficiency.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | OUT | Amplifier output - capable of sourcing/sinking ±50mA; requires local 0.1µF ceramic bypass to VDD/VSS. |
| 2 | IN− | Inverting input - high-impedance node; sensitive to layout-induced noise; pair with matched trace lengths in differential apps. |
| 3 | IN+ | Noninverting input - accepts common-mode voltages from VSS to VDD; use for reference-biased sensor interfaces. |
| 4 | VSS | Negative supply / ground reference - substrate tied internally to VSS; must be low-impedance connection. |
| 5 | VDD | Positive supply - bypass with 0.1µF ceramic capacitor placed ≤2mm from pin to suppress high-frequency supply noise. |
| 6 | NC | No connect - electrically isolated; leave unconnected and unpopulated on PCB. |
| 7 | NC | No connect - electrically isolated; no internal connection; avoid routing signals underneath. |
| 8 | NC | No connect - electrically isolated; do not tie to VDD, VSS, or other nets. |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-Rail Input/Output | Enables full utilization of supply rails in single-supply systems - eliminates need for level-shifting or dual supplies in portable gear. |
| 10V/µs Slew Rate @ 5V | Supports >100kHz small-signal bandwidth with minimal distortion - critical for audio preamps and fast-settling data acquisition. |
| 50pA Input Bias Current | Reduces offset drift in high-Z transducer interfaces (e.g., pH electrodes, piezoelectric sensors) without guard traces. |
| 300pF Capacitive Load Stability | Permits direct connection to SAR ADC inputs (typically 10–30pF) and long traces without added series resistance or compensation. |
| Automotive Temp Range | Guaranteed operation from –40°C to +125°C - meets AEC-Q100 stress test requirements for engine control and ADAS modules. |
| Low 800µA Supply Current | Extends battery life in always-on sensor nodes - draws less than 1mA per channel at 5V, enabling multi-channel systems on coin cells. |
Applications
| Automotive Current Sensing | Portable Medical Instrumentation |
|---|---|
|
Use Scenario: High-side current monitoring in 12V vehicle battery management systems, measuring charge/discharge currents up to 50A via shunt resistor. IC Role / Device Role / Timing Role: Precision difference amplifier with rail-to-rail output driving 12-bit SAR ADC input - configured as noninverting gain-of-20 stage. Use Value: Delivers sub-1% total error over temperature due to low VOS drift (±0.3µV/°C) and rail-to-rail swing preserving full ADC code range. |
Use Scenario: Amplifying weak ECG electrode signals (0.5–5mVpp) in handheld patient monitors powered by two AA batteries. IC Role / Device Role / Timing Role: First-stage instrumentation amplifier input buffer - provides high Zin (>1TΩ), low noise (12nV/√Hz), and DC-coupled signal path. Use Value: Enables >85dB SNR at 1kHz with 800µA quiescent current - extends runtime beyond 72 hours on alkaline cells. |
| Industrial Temperature Transducers | RF Power Amplifier Control |
|
Use Scenario: Linearizing and amplifying PT100 RTD bridge outputs in programmable logic controller (PLC) analog input modules. IC Role / Device Role / Timing Role: Low-drift, low-noise voltage follower driving ratiometric ADC reference - rejects common-mode noise from 24V field wiring. Use Value: Achieves ±0.1°C accuracy from –25°C to +85°C using integrated 50pA IB and 1.5mV VOS max - no calibration required. |
Use Scenario: Closed-loop bias control of GaN RF power amplifiers in 5G base station remote radio units (RRUs). IC Role / Device Role / Timing Role: Fast-settling error amplifier comparing detector diode output to DAC reference - regulates gate voltage with 10V/µs response. Use Value: Maintains amplifier linearity within 0.5dB across 100MHz–3.5GHz band by eliminating slow thermal drift in bias loop. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar rail-to-rail op amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TSV911ICT | Lower GBWP (8MHz), higher supply current (1.1mA), wider VDD range (2.5–36V); no guaranteed 125°C operation. | Targeted at general-purpose industrial automation, not automotive-qualified; lacks capacitive-load stability spec. | Choose for wide-supply flexibility where temperature range ≤105°C suffices and cost is primary constraint. |
| AD8601ARTZ-REEL7 | Higher precision (VOS = 600µV max), lower noise (12nV/√Hz), same 10MHz GBWP; only rated to +125°C with derating. | Optimized for precision instrumentation; lacks explicit 300pF capacitive-load guarantee and automotive qualification. | Prefer when sub-mV offset and low drift dominate over guaranteed high-temp reliability and drive strength. |
Compared with TSV911ICT and AD8601ARTZ-REEL7, the MAX4491AUA-T uniquely combines automotive-grade temperature assurance, 300pF capacitive-load stability, and 10V/µs slew rate in a compact µMAX package - making it the only option among the three qualified for under-hood current sensing and high-speed sensor signal chains without external compensation.
Availability
MAX4491AUA-T is available at Aetrix Electronics and suitable for automotive battery monitoring, portable medical diagnostics, industrial RTD signal conditioning, and RF amplifier bias control requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX4491AUA-T 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
Maxim Integrated (now part of Analog Devices) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power-management ICs for demanding industrial, automotive, and communications applications.
The MAX4491AUA-T belongs to Maxim's precision rail-to-rail op amp family engineered for low-voltage, high-speed signal conditioning in space-constrained, thermally aggressive environments - emphasizing robustness, stability, and ease of use in production systems.
FAQ
What is the operating temperature range guaranteed for the MAX4491AUA-T?
The MAX4491AUA-T is fully specified and production-tested over –40°C to +125°C, meeting automotive AEC-Q100 Grade 0 requirements. All electrical parameters - including input offset voltage, supply current, and output swing - are guaranteed across this full range, with no derating needed. This makes the MAX4491AUA-T suitable for under-hood engine control units and industrial motor drives where ambient temperatures exceed 105°C.
Does the MAX4491AUA-T support single-supply operation with rail-to-rail input and output?
Yes, the MAX4491AUA-T supports true rail-to-rail input common-mode range (VSS to VDD) and rail-to-rail output swing (within 55mV of each rail into 2kΩ). It operates from a single 2.7V to 5.5V supply, enabling direct interfacing with 3.3V microcontrollers and battery-powered sensors without level-shifting circuitry. The input stage uses parallel NMOS/PMOS pairs to achieve full rail coverage.
What is the maximum capacitive load the MAX4491AUA-T can drive without oscillation?
The MAX4491AUA-T is unity-gain stable and characterized for reliable operation with capacitive loads up to 300pF, as confirmed in the datasheet's "Capacitive-Load Stability" plot and transient response figures. This allows direct connection to typical SAR ADC input capacitors (10–50pF) and longer PCB traces without adding isolation resistors - simplifying layout and preserving signal integrity in data acquisition systems.
How does the input bias current of the MAX4491AUA-T affect high-impedance sensor interfaces?
The MAX4491AUA-T features an ultra-low input bias current of ±50pA (typical), which minimizes voltage error across high-value feedback or source impedances. For example, with a 10MΩ sensor impedance, the resulting offset is just 0.5mV - critical for accurate measurements from thermistors, photodiodes, or pH electrodes. This performance is maintained across the full –40°C to +125°C range without significant drift.
Is the MAX4491AUA-T pin-compatible with other op amps in the MAX449x family?
No - the MAX4491AUA-T uses an 8-pin µMAX package with pins 6–8 designated NC (no connect), whereas the MAX4490 uses SC70-5 and MAX4492 uses TSSOP-14/SO-14. While functional behavior is consistent across the family, physical pinouts differ entirely. Board redesign is required when substituting between MAX4490, MAX4491AUA-T, and MAX4492 variants due to incompatible pin counts and layouts.
MAX4491AUA-T Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Amplifier Type:
- General Purpose
- Number of Circuits:
- 2
- Output Type:
- Push-Pull, Rail-to-Rail
- Slew Rate:
- 10V/µs
- Gain Bandwidth Product:
- 10 MHz
- -3db Bandwidth:
- -
- Current - Input Bias:
- 50 pA
- Voltage - Input Offset:
- 1.5 mV
- Current - Supply:
- 800µA (x2 Channels)
- Current - Output / Channel:
- 50 mA
- Voltage - Supply Span (Min):
- 2.7 V
- Voltage - Supply Span (Max):
- 5.5 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-uMAX/uSOP
MAX4491AUA-T FAQ
1.How can I place an order for MAX4491AUA-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX4491AUA-T 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 MAX4491AUA-T reliable?
The price and inventory of MAX4491AUA-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX4491AUA-T is usually 5 days.
3.What payment methods are accepted for MAX4491AUA-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX4491AUA-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX4491AUA-T?
MAX4491AUA-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX4491AUA-T 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 MAX4491AUA-T?
For technical support, including MAX4491AUA-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX4491AUA-T requirements.
6.How does Aetrix verify that MAX4491AUA-T is sourced from the original manufacturer or authorized distributors?
All MAX4491AUA-T 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 MAX4491AUA-T meets industry standards.
7.What is the process for return or replacement of MAX4491AUA-T?
All MAX4491AUA-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX4491AUA-T, 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 MAX4491AUA-T part is unused and in its original packaging.
Return procedure for MAX4491AUA-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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