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Analog Devices Inc./Maxim Integrated MAX4491AUA
- Part No.:
- MAX4491AUA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX4491AUA.pdf
- Description:
- IC OPAMP GP 2 CIRCUIT 8UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:4,688
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Product details
Overview
MAX4491AUA from Maxim Integrated is a dual, low-cost CMOS operational amplifier featuring rail-to-rail input and output operation across 2.7V to 5.5V single supply or ±1.35V to ±2.75V dual supplies, 10MHz gain-bandwidth product, 10V/µs slew rate, and 50pA input bias current. It drives 2kΩ loads to within 55mV of either rail and remains unity-gain stable with up to 300pF capacitive load - ideal for high-side/low-side current sensing in automotive-grade power management systems.
For engineers reviewing the MAX4491AUA datasheet, MAX4491AUA pinout, MAX4491AUA application, or MAX4491AUA equivalent, key selection criteria include its AEC-Q100 qualified -40°C to +125°C operation, µMAX-8 package footprint, dual-channel rail-to-rail I/O performance, and verified capacitive-load stability - critical for battery-powered instrumentation and sensor signal conditioning where precision, low voltage headroom, and thermal robustness are mandatory.
Technical Context
The MAX4491AUA implements parallel N- and P-channel differential input stages enabling rail-to-rail common-mode input range (VSS to VDD), with each stage active over complementary voltage regions. Its class-AB push-pull output stage delivers ±50mA short-circuit current and sustains 55mV output swing into 2kΩ at full temperature range.
It achieves unity-gain stability with 300pF capacitive loads without external compensation, supported by 60° phase margin and 10dB gain margin at 10MHz. Input capacitance is 5pF, requiring gain-setting resistor networks below 3kΩ for optimal AC stability in inverting/noninverting configurations.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2.7V to 5.5V single supply - enables direct interface with Li-ion battery and 3.3V/5V logic domains. |
| Gain-Bandwidth Product | 10MHz - supports closed-loop bandwidths up to ~1MHz at gain = 10 for audio and sensor signal conditioning. |
| Slew Rate | 10V/µs - ensures faithful reproduction of fast transients in current-sense feedback loops and RF PA control. |
| 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 - provides maximum dynamic range in low-voltage systems with tight rail margins. |
| Capacitive Load Drive | Stable with ≤300pF - eliminates need for isolation resistors in ADC driver or filter buffer applications. |
| Operating Temperature | -40°C to +125°C - qualified for under-hood automotive, industrial motor control, and harsh-environment embedded use. |
Pinout & Package
MAX4491AUA 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, and optimized for space-constrained PCB layouts in portable and automotive modules.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | INA− | Inverting input for Amplifier A - connects to feedback network in standard op-amp configurations. |
| 2 | VSS | Negative supply / ground reference - substrate tied internally to VSS; must be low-impedance for noise immunity. |
| 3 | INA+ | Noninverting input for Amplifier A - accepts sensor signals, reference voltages, or buffered inputs. |
| 4 | OUTA | Amplifier A output - drives downstream circuitry; capable of sourcing/sinking ±50mA short-circuit current. |
| 5 | OUTB | Amplifier B output - independent output channel; shares same supply rails and thermal characteristics as OUTA. |
| 6 | INB− | Inverting input for Amplifier B - used for differential amplification, active filtering, or second-stage gain. |
| 7 | INB+ | Noninverting input for Amplifier B - enables dual-channel signal processing without cross-talk degradation. |
| 8 | VDD | Positive supply input - requires local 0.1µF ceramic bypass capacitor placed within 2mm of pin for EMI suppression. |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-Rail Input/Output | Enables full-supply utilization in single-supply systems - e.g., 0–5V input range with 0–5V output swing into 2kΩ. |
| 10V/µs Slew Rate | Supports >100kHz full-power bandwidth at 10Vpp output - essential for fast-settling current-sense amplifiers. |
| Unity-Gain Stability (≤300pF) | Eliminates need for external compensation in ADC driver, filter, or cable-drive applications - reduces BOM count. |
| 50pA Input Bias Current | Reduces offset error in high-Z source applications (e.g., pH electrodes, piezoelectric sensors) by <100µV at 2MΩ source impedance. |
| AEC-Q100 Qualified | Validated for automotive electronics per Grade 1 (-40°C to +125°C) - meets reliability requirements for engine control and ADAS subsystems. |
Applications
| High-Side Current Sensing | Low-Power Audio Signal Conditioning |
|---|---|
|
Use Scenario: Monitoring motor phase current in 12V automotive ECUs using shunt resistor between load and battery positive. IC Role / Device Role / Timing Role: Dual op-amp configured as difference amplifier (A) and gain stage (B) to reject common-mode voltage up to 12V while amplifying mV-level shunt drops. Use Value: Rail-to-rail input accepts 0–12V common-mode; rail-to-rail output delivers full-scale signal to 12-bit SAR ADC without level-shifting. |
Use Scenario: Pre-amplifying microphone output in battery-powered voice recorder with 3.3V supply and 100kΩ load. IC Role / Device Role / Timing Role: First-stage noninverting amplifier (A) with gain = 100, second-stage low-pass filter (B) suppressing RF interference. Use Value: 10MHz GBW ensures flat frequency response to 20kHz; 50pA IB prevents DC drift in AC-coupled topology. |
| Battery Voltage Monitoring | RF Power Amplifier Control Loop |
|
Use Scenario: Measuring Li-ion cell voltage during charge/discharge cycles in portable medical devices operating from 2.7V–4.2V supply. IC Role / Device Role / Timing Role: Precision buffer (A) followed by comparator interface (B) - maintains accuracy across entire battery voltage range. Use Value: Input offset voltage ≤10mV max ensures <0.25% measurement error; 2.7V min supply allows operation down to near-end-of-life cell voltage. |
Use Scenario: Closed-loop bias control for GaN RF PA in 5G small-cell base stations, requiring fast response to thermal drift. IC Role / Device Role / Timing Role: Error amplifier (A) comparing sensed drain current to reference; integrator (B) generating stable gate bias voltage. Use Value: 10V/µs slew rate enables <1µs settling time after step changes; unity-gain stability avoids oscillation with PA output capacitance. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual rail-to-rail op amp applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV2462IDR | Lower slew rate (1.6V/µs), wider supply (2.7–6V), higher input bias current (10nA), SO-8 only. | Not qualified for automotive temp range; suitable for industrial/commercial portable gear with relaxed speed needs. | Choose when cost sensitivity outweighs speed and temperature requirements - lower unit price but reduced dynamic performance. |
| AD8602ARZ | Higher precision (30µV VOS), lower noise (12nV/√Hz), same 10MHz GBW, but only stable to 100pF capacitive load. | Preferred for precision sensor front-ends where offset and noise dominate; unsuitable for direct ADC driving with >100pF trace capacitance. | Choose when DC accuracy and low noise are critical and capacitive loading is controlled - requires external compensation for >100pF loads. |
Compared with TLV2462IDR and AD8602ARZ, the MAX4491AUA uniquely balances high-speed rail-to-rail operation, automotive temperature qualification, and proven 300pF capacitive-load stability - making it the optimal choice for real-time current sensing and fast-settling control loops where both speed and ruggedness are required.
Availability
MAX4491AUA is available at Aetrix Electronics and suitable for automotive powertrain monitoring, industrial motor control, and portable medical instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX4491AUA 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) designs high-performance analog and mixed-signal ICs for automotive, industrial, communications, and computing applications - emphasizing integration, reliability, and power efficiency.
The MAX4490/MAX4491/MAX4492 family targets cost-sensitive, high-speed signal conditioning in space-constrained environments - delivering rail-to-rail I/O, low quiescent current, and automotive-grade operation without sacrificing bandwidth or drive capability.
FAQ
What is the operating temperature range guaranteed for MAX4491AUA?
The MAX4491AUA is specified and production-tested over -40°C to +125°C, meeting AEC-Q100 Grade 1 requirements for automotive applications. All electrical parameters - including input offset voltage, supply current, and output swing - are guaranteed across this full range, with typical performance characterized at +25°C. This makes MAX4491AUA suitable for under-hood engine control units and industrial motor drives exposed to extreme thermal cycling.
Does MAX4491AUA support single-supply operation, and what is the minimum supply voltage?
Yes, MAX4491AUA supports true single-supply operation from 2.7V to 5.5V, with rail-to-rail input and output functionality fully functional at the 2.7V minimum. At this voltage, it maintains 10MHz gain-bandwidth product, 10V/µs slew rate, and output swing within 55mV of both rails into 2kΩ - enabling reliable operation in Li-ion powered systems where supply voltage decays from 4.2V to 2.7V during discharge.
Can MAX4491AUA drive a 100kΩ load to within 1.5mV of the supply rails?
Yes, MAX4491AUA's class-AB output stage guarantees output-voltage swing of VSS + 1.5mV to VDD – 1.5mV when driving a 100kΩ load referenced to VDD/2, as confirmed in the Electrical Characteristics table. This ultra-low headroom is enabled by complementary PMOS/NMOS output transistors and is maintained across the full -40°C to +125°C temperature range - critical for precision reference buffering and high-resolution DAC output stages.
Is MAX4491AUA pin-compatible with other packages in the MAX449x family?
No, MAX4491AUA uses the 8-pin µMAX package, which is physically and electrically distinct from the SC70-5 (MAX4490), SOT23-5 (MAX4490AUK-T), and TSSOP-14/SO-14 (MAX4492) variants. While all share identical electrical specifications and pin functions per channel, the µMAX-8 layout (with dual amplifiers occupying pins 1–4 and 5–8) is not mechanically interchangeable - board redesign is required when migrating from or to other packages in the family.
What is the maximum capacitive load MAX4491AUA can drive without external compensation?
MAX4491AUA is unity-gain stable with capacitive loads up to 300pF, as validated in the Capacitive-Load Stability graph and Typical Operating Characteristics. This allows direct connection to ADC input capacitors, long PCB traces, or filter networks without adding series isolation resistors or feedback compensation capacitors - simplifying design and preserving signal integrity in data acquisition and sensor interface circuits.
MAX4491AUA Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tube
- 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 FAQ
1.How can I place an order for MAX4491AUA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX4491AUA 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 reliable?
The price and inventory of MAX4491AUA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX4491AUA is usually 5 days.
3.What payment methods are accepted for MAX4491AUA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX4491AUA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX4491AUA?
MAX4491AUA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX4491AUA 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?
For technical support, including MAX4491AUA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX4491AUA requirements.
6.How does Aetrix verify that MAX4491AUA is sourced from the original manufacturer or authorized distributors?
All MAX4491AUA 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 meets industry standards.
7.What is the process for return or replacement of MAX4491AUA?
All MAX4491AUA units undergo pre-shipment inspection (PSI). If there is an issue with MAX4491AUA, 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 part is unused and in its original packaging.
Return procedure for MAX4491AUA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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