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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:189
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Product details
Overview
MAX4491AUA+ from Maxim Integrated is a dual, low-cost CMOS operational amplifier with rail-to-rail input and output capability, operating from a single 2.7V to 5.5V supply or dual ±1.35V to ±2.75V supplies. It delivers 10MHz gain-bandwidth product, 10V/µs slew rate, and drives 2kΩ loads to within 55mV of either rail - 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 capacitive-load stability up to 300pF, ±50mA short-circuit output current, 50pA input bias current, and guaranteed operation across –40°C to +125°C.
Technical Context
The MAX4491AUA+ integrates two independent amplifiers in an 8-pin µMAX package, each featuring parallel N- and P-channel differential input stages enabling true rail-to-rail common-mode input range (VSS to VDD). Its class-AB push-pull output stage supports rail-to-rail swing under load while maintaining unity-gain stability with up to 300pF capacitive loading.
Input bias current is specified at ±0.05nA (typ), input offset voltage at ±1.5mV (max), and PSRR/CMRR exceed 100dB/75dB respectively over temperature - critical for precision sensor signal conditioning in noisy automotive environments where supply rejection and common-mode immunity directly impact measurement fidelity.
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 systems and 3.3V/5V logic domains without level-shifting. |
| Gain-Bandwidth Product | 10MHz - supports stable closed-loop gain ≥10 at 1MHz, suitable for active filters and fast-settling sensor interfaces. |
| Slew Rate | 10V/µs - ensures ≤400ns 4V step response, critical for pulse-amplification in RF PA control loops. |
| Input Bias Current | ±0.05nA (max) - minimizes voltage error across high-impedance sensor bridges (e.g., 1MΩ thermistor networks). |
| Output Swing (RL = 2kΩ) | Within 55mV of VDD/VSS rails - preserves dynamic range in low-voltage, single-supply data acquisition front-ends. |
| Capacitive Load Drive | Stable with up to 300pF - eliminates need for external isolation resistors when driving ADC input capacitance or long PCB traces. |
| Operating Temperature | –40°C to +125°C - qualified for under-hood automotive applications per AEC-Q100 stress test requirements. |
Pinout & Package
MAX4491AUA+ is housed in an 8-pin µMAX package (2.1mm × 2.3mm, 0.5mm pitch), optimized for space-constrained automotive and portable designs. The package features exposed pad for thermal enhancement and is RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | INA− | Inverting input of Amplifier A - connects to feedback network in inverting configurations or sensor reference in differential setups. |
| 2 | VSS | Negative supply rail - must be connected to ground (single supply) or negative rail (dual supply); substrate tied to this pin. |
| 3 | INA+ | Noninverting input of Amplifier A - accepts rail-to-rail common-mode signals up to VDD, enabling direct connection to battery-sense nodes. |
| 4 | OUTA | Output of Amplifier A - capable of sourcing/sinking ±50mA; requires local 0.1µF ceramic bypass capacitor at VDD pin for stability. |
| 5 | OUTB | Output of Amplifier B - independently buffered; allows dual-path signal processing (e.g., current sense + voltage monitor) without crosstalk degradation. |
| 6 | INB− | Inverting input of Amplifier B - electrically isolated from Amplifier A; supports separate gain-setting networks per channel. |
| 7 | INB+ | Noninverting input of Amplifier B - shares same rail-to-rail input architecture as INA+, enabling matched performance across both channels. |
| 8 | VDD | Positive supply input - accepts 2.7V–5.5V; PSRR >100dB ensures minimal supply ripple coupling into output signals. |
Key Features
| Feature | Design Value |
|---|---|
| Rail-to-Rail Input Common-Mode Range | Extends from VSS to VDD - eliminates need for input biasing resistors when interfacing with unbuffered sensors or DAC outputs. |
| Rail-to-Rail Output Swing (2kΩ load) | Within 55mV of supply rails - maximizes usable signal swing in 3.3V systems, improving SNR in low-voltage data converters. |
| Unity-Gain Stability with Capacitive Loads | Up to 300pF - simplifies layout for ADC driver stages and eliminates external compensation components in most applications. |
| Low Input Bias Current (±0.05nA max) | Reduces offset drift in high-Z transducer interfaces (e.g., piezoelectric sensors, pH electrodes) across automotive temperature range. |
| High PSRR (100dB min) | Maintains accuracy during battery discharge cycles - critical for fuel gauge ICs and battery monitoring units requiring stable reference scaling. |
Applications
| Battery Monitoring Unit | RF Power Amplifier Control |
|---|---|
Use Scenario: Real-time cell voltage and current measurement in 12V automotive battery management systems with integrated coulomb counting. IC Role / Device Role / Timing Role: Dual op amp configured as high-side current shunt amplifier (Channel A) and differential battery voltage monitor (Channel B). Use Value: Rail-to-rail input enables direct sensing of shunt voltage near ground; 10V/µs slew rate supports fast transient detection during load dump events. | Use Scenario: Closed-loop bias control for GaN HEMT power amplifiers in 5G base station front-ends. IC Role / Device Role / Timing Role: Precision current mirror reference amplifier generating gate bias voltage proportional to PA output power. Use Value: 50pA input bias current prevents drift in high-impedance bias networks; 300pF capacitive drive capability stabilizes loop filter integration capacitors. |
| Automotive Cabin Pressure Sensor | Industrial Current Loop Transmitter |
Use Scenario: Signal conditioning for MEMS-based cabin pressure sensors in HVAC control modules, operating across –40°C to +125°C. IC Role / Device Role / Timing Role: Low-noise, rail-to-rail instrumentation amplifier front-end with programmable gain via external resistors. Use Value: 12nV/√Hz voltage noise density preserves resolution of sub-mbar pressure changes; 10MHz GBW supports digital filtering at 1kHz sampling rates. | Use Scenario: 4–20mA transmitter for industrial temperature transmitters using RTD or thermocouple inputs. IC Role / Device Role / Timing Role: Dual-channel signal conditioner: Channel A amplifies sensor output; Channel B drives 4–20mA loop with precise current regulation. Use Value: ±50mA short-circuit output current ensures robustness against loop wiring faults; 100dB PSRR rejects noise from shared 24V DC supply rails. |
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 |
|---|---|---|---|
| TSV912IDT | Lower GBW (8MHz), higher input bias current (1pA), SOT23-8 package - no exposed thermal pad. | Not qualified for automotive temperature range; max operating temp +105°C. | Preferred for cost-sensitive consumer applications where extended temperature range is not required. |
| LMV358QDRQ1 | Lower slew rate (1V/µs), lower GBW (1MHz), wider supply range (2.7V–5.5V), AEC-Q100 Grade 1 certified. | Optimized for low-power, low-bandwidth sensor buffering - insufficient for fast current-sense transient response. | Select when ultra-low quiescent current (40µA/ch) outweighs speed requirements in always-on automotive modules. |
Compared with TSV912IDT and LMV358QDRQ1, the MAX4491AUA+ uniquely balances 10MHz bandwidth, 10V/µs slew rate, and full automotive temperature qualification - making it the only option among the three capable of simultaneously meeting high-speed current sensing and AEC-Q100 Grade 0 requirements.
Availability
MAX4491AUA+ is available at Aetrix Electronics and suitable for automotive battery management, RF power amplifier control, cabin pressure sensing, and industrial 4–20mA transmitter designs 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 precision analog, mixed-signal, and power management ICs for automotive, industrial, and communications markets.
The MAX4490/MAX4491/MAX4492 family was engineered specifically for high-speed, rail-to-rail signal conditioning in space-constrained, temperature-extreme applications - emphasizing low power, high accuracy, and robust capacitive-load drive capability.
FAQ
What is the maximum capacitive load the MAX4491AUA+ can drive without instability?
The MAX4491AUA+ maintains unity-gain stability with capacitive loads up to 300pF, as verified in the manufacturer's Typical Operating Characteristics (Figure 4b). This specification applies under standard conditions: VDD = 5V, RL = 100kΩ, and TA = +25°C. For loads exceeding 300pF, an isolation resistor (typically 10Ω) is recommended between the MAX4491AUA+ output and the load capacitance to preserve phase margin and prevent ringing.
Does the MAX4491AUA+ support single-supply operation at 3.3V?
Yes, the MAX4491AUA+ fully supports single-supply operation from 2.7V to 5.5V, including 3.3V systems. At VDD = 3.3V, it retains rail-to-rail input common-mode range (0V to 3.3V) and delivers output swing within 55mV of both rails into 2kΩ loads. Supply current remains ~800µA per amplifier, and all key specs - including 10MHz GBW and 10V/µs slew rate - are guaranteed across the full temperature range.
What is the input offset voltage specification for the MAX4491AUA+ over temperature?
The MAX4491AUA+ has a maximum input offset voltage of ±10mV over the full operating temperature range (–40°C to +125°C), with ±1.5mV typical at +25°C. This parameter is tested and guaranteed at both ends of the common-mode range (VSS and VDD), ensuring predictable performance in high-side current sensing where input voltage swings near the supply rails.
Is the MAX4491AUA+ pin-compatible with other devices in the MAX449x family?
No, the MAX4491AUA+ is not pin-compatible with the MAX4490 or MAX4492. It uses an 8-pin µMAX package with dedicated dual-amplifier pinout (INA−, VSS, INA+, OUTA, OUTB, INB−, INB+, VDD), whereas MAX4490 is 5-pin SC70 and MAX4492 is 14-pin TSSOP/SO. Pin assignments differ fundamentally - substitution requires PCB redesign and layout validation.
What thermal considerations apply to the MAX4491AUA+ in continuous operation?
The MAX4491AUA+'s 8-pin µMAX package includes an exposed thermal pad that must be soldered to a PCB copper pour for effective heat dissipation. With derating of 4.1mW/°C above +70°C, its maximum continuous power dissipation is 330mW at +70°C ambient. In a typical +105°C under-hood environment with 2×2cm² 2-oz copper, junction temperature stays below 135°C at full load - well within the +150°C absolute maximum rating.
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:
- Active
- 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.
MAX4491AUA+ Tags
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