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Analog Devices Inc./Maxim Integrated MAX4081FAUA-T
- Part No.:
- MAX4081FAUA-T
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX4081FAUA-T.pdf
- Description:
- IC CURRENT SENSE 1 CIRCUIT 8UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:4,838
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Product details
Overview
The MAX4081FAUA-T from Maxim Integrated is a bidirectional, high-side current-sense amplifier with 5V/V gain, operating from 4.5V to 76V supply and supporting ±500mV full-scale sense voltage. It features ±0.1% gain accuracy, 100µV input offset voltage, and delivers output referenced to an external VREF (via REF1A/REF1B), enabling precise charge/discharge monitoring in battery systems. It is used in automotive 12V/24V battery management and telecom 48V backplane current measurement.
For engineers reviewing the MAX4081FAUA-T datasheet, MAX4081FAUA-T pinout, MAX4081FAUA-T application, or MAX4081FAUA-T equivalent, key selection criteria include its bidirectional sensing capability, 76V common-mode range independent of VCC, µMAX-8 package footprint, and need for external reference configuration - all critical for high-voltage, polarity-aware power monitoring designs.
Technical Context
The MAX4081FAUA-T implements a precision current mirror-based architecture that maintains constant input terminal voltages across RSENSE during bidirectional current flow, enabling accurate VSENSE = (VRS+ − VRS−) measurement regardless of polarity. Its output stage level-shifts relative to VREF (average of REF1A/REF1B), producing VOUT = VREF ± (VSENSE × 5V/V) - supporting symmetric ±2.5V swing around VREF when VSENSE = ±500mV.
Unlike unidirectional variants, the MAX4081FAUA-T requires dual reference inputs (REF1A and REF1B) to define zero-current output level; connecting REF1B to GND sets VREF = VREF1A/2, while tying both to a stable source sets VREF = average voltage. This architecture avoids separate polarity outputs and eliminates need for external level-shifting circuitry.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 5V/V - scales ±500mV sense voltage to ±2.5V output swing around VREF, matching standard ADC input ranges. |
| Full-Scale Sense Voltage | ±500mV - supports accurate bidirectional current measurement up to ±1A with 500mΩ sense resistor. |
| Input Offset Voltage | ±0.1mV (typ) - contributes <0.02% error at full-scale, critical for low-current battery monitoring accuracy. |
| Common-Mode Range | 4.5V to 76V - enables direct high-side sensing on 12V/24V/48V/72V rails without level-shifting or ground disruption. |
| Supply Current | 103µA (typ) - allows continuous operation in always-on battery monitoring circuits with minimal quiescent drain. |
| Bandwidth | 150kHz - sufficient for motor control loop feedback and fast-charging transient detection. |
| Operating Temperature | −40°C to +125°C - qualified for under-hood automotive and industrial power-system environments. |
Pinout & Package
The MAX4081FAUA-T is housed in an 8-pin µMAX® package (pin-compatible with SO-8 but 30% smaller footprint), with exposed pad for thermal enhancement. Pin 1 is RS+, pin 4 is GND, pin 5 is OUT, pin 8 is RS−, and pins 6–7 are dedicated reference inputs (REF1B and REF1A).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (RS+) | High-side sense input | Connects to positive side of external current-sense resistor; withstands up to 76V common-mode voltage. |
| 2 (VCC) | Supply input | Independent 4.5V–76V supply rail; decoupling capacitor required between VCC and GND. |
| 3,6,7 (N.C.) | No internal connection | Pins 3 and 6 are unconnected; pin 7 is REF1A - critical for setting VREF level in bidirectional mode. |
| 4 (GND) | Analog ground reference | Return path for internal circuitry; must be connected to system ground with low-impedance trace. |
| 5 (OUT) | Voltage output | Delivers VREF ± (5 × VSENSE); output swings above/below VREF to indicate charge/discharge polarity. |
| 8 (RS−) | Low-side sense input | Connects to negative side of sense resistor; differential input with RS+ defines VSENSE. |
| - (REF1B) | Reference input | Pin 6 - tied to REF1A or GND to configure VREF = (REF1A + REF1B)/2; determines zero-current output point. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional current sensing | Single OUT pin continuously indicates charge (VOUT > VREF) and discharge (VOUT < VREF) without polarity switching or extra logic. |
| External reference configuration | REF1A/REF1B inputs allow flexible VREF setup - either as mid-supply reference or scaled-down version - optimizing dynamic range for asymmetric load conditions. |
| 76V independent common-mode and supply range | Enables direct sensing on high-voltage rails (e.g., 48V telecom, 72V EV subsystems) while powering from lower auxiliary supplies (e.g., 5V or 12V). |
| ±0.1% gain accuracy over temperature | Ensures consistent current-to-voltage conversion across −40°C to +125°C, eliminating calibration drift in automotive and industrial deployments. |
| 100µV input offset voltage (max) | Minimizes baseline error in low-current applications such as standby leakage monitoring or photodiode bias current sensing. |
Applications
| Automotive Battery Management | 48V Telecom Backplane Monitoring |
|---|---|
Use Scenario: Real-time monitoring of charge/discharge current in 12V/24V starter batteries and 48V mild-hybrid vehicle subsystems. IC Role / Device Role / Timing Role: High-side current-sense amplifier providing polarity-aware analog output to microcontroller ADC for state-of-charge estimation. Use Value: Enables accurate coulomb counting with single device and no PCB-level polarity switching, reducing BOM count and layout complexity. | Use Scenario: Continuous current measurement on 48V DC distribution backplanes in telecom base stations and data center PSUs. IC Role / Device Role / Timing Role: High-voltage, high-accuracy current monitor interfacing with isolated ADC or power management IC for fault detection and load balancing. Use Value: 76V common-mode range allows direct placement on hot-swap power rails without attenuators or isolation, improving measurement fidelity and response time. |
| Bidirectional Motor Control Feedback | Smart Power Supply Current Sensing |
Use Scenario: Closed-loop current feedback in H-bridge motor drivers for robotics and industrial actuators requiring regenerative braking detection. IC Role / Device Role / Timing Role: Bidirectional sense amplifier delivering real-time ILOAD polarity and magnitude to PWM controller or FPGA for torque and direction control. Use Value: Eliminates need for dual unidirectional amplifiers or external comparators, simplifying feedback path and reducing latency in current-loop bandwidth. | Use Scenario: Precision output current monitoring in programmable lab power supplies and battery chargers with active load regulation. IC Role / Device Role / Timing Role: High-accuracy, high-common-mode current sensor feeding analog control loop and digital supervision circuitry. Use Value: ±0.1% gain accuracy and low offset ensure tight current regulation (<±0.5%) across full operating temperature range, meeting Class II lab equipment specs. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional high-side current sensing applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| INA226AIDGST | 2.7V–5.5V supply only; I²C digital output; 16-bit resolution; no external reference needed. | Requires microcontroller with I²C interface; unsuitable for analog-only or high-voltage (>5.5V) supply domains. | Select when digital output, integrated ADC, and low supply voltage are prioritized over analog simplicity and 76V common-mode capability. |
| MAX4081TAUA+ | 20V/V gain; ±125mV full-scale sense voltage; same µMAX-8 package and pinout. | Better suited for higher-current, lower-resistance sensing (e.g., 500mΩ → ±2.5A), but reduced voltage resolution per mA. | Select when higher full-scale current range is needed and ±125mV VSENSE provides adequate signal-to-noise ratio for target accuracy. |
Compared with INA226AIDGST and MAX4081TAUA+, the MAX4081FAUA-T offers optimal balance of analog simplicity, 76V common-mode tolerance, and ±500mV full-scale sensitivity - making it ideal for cost-sensitive, high-voltage, polarity-critical analog monitoring where I²C overhead or gain mismatch is unacceptable.
Availability
MAX4081FAUA-T is available at Aetrix Electronics and suitable for automotive battery management, 48V telecom backplane monitoring, and bidirectional motor control applications requiring stable component supply and long-term industrial availability.
Supply support for MAX4081FAUA-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) designs precision analog, mixed-signal, and power-management ICs for demanding industrial, automotive, and communications applications.
The MAX4080/MAX4081 product line was engineered specifically for high-voltage, high-accuracy current sensing in safety-critical power systems - emphasizing wide common-mode range, bidirectional capability, and automotive-grade reliability.
FAQ
What is the function of REF1A and REF1B on the MAX4081FAUA-T?
REF1A and REF1B set the zero-current reference voltage (VREF) for the MAX4081FAUA-T's bidirectional output. VREF equals their average; connecting REF1B to GND yields VREF = REF1A/2, while tying both to a stable source sets VREF = (REF1A + REF1B)/2. This defines the midpoint of the output swing, ensuring VOUT = VREF when VSENSE = 0V. The MAX4081FAUA-T relies on this configuration to distinguish charge from discharge states.
Can the MAX4081FAUA-T operate with a supply voltage lower than its common-mode input voltage?
Yes - the MAX4081FAUA-T supports independent supply (VCC) and common-mode (VRS+) ranges, both rated 4.5V to 76V. This means it can monitor a 48V bus while powered from a 5V auxiliary rail, eliminating need for level-shifting or isolated supplies. The MAX4081FAUA-T maintains full accuracy and functionality as long as both VCC and VRS+ remain within their respective 4.5V–76V limits.
What is the maximum sense resistor value compatible with the MAX4081FAUA-T for ±1A full-scale current?
For ±1A full-scale current and ±500mV full-scale sense voltage, the maximum recommended sense resistor is 500mΩ. This ensures VSENSE stays within the MAX4081FAUA-T's specified ±500mV range at full scale. Using larger resistors risks exceeding the input voltage limit or increasing IR drop and power loss; 500mΩ also balances accuracy (minimizing offset impact) and efficiency. The MAX4081FAUA-T's 100µV offset contributes <0.02% error at this scale.
Does the MAX4081FAUA-T require external passive components for basic operation?
Yes - the MAX4081FAUA-T requires at minimum: (1) a 0.1µF ceramic capacitor between VCC and GND for supply bypassing; (2) an external current-sense resistor (RSENSE) placed between RS+ and RS−; and (3) a stable reference voltage source connected to REF1A/REF1B to establish VREF. No additional op-amps, level shifters, or polarity logic are needed due to its integrated bidirectional architecture. These components define the MAX4081FAUA-T's sensing range and accuracy.
How does the MAX4081FAUA-T handle overcurrent or saturation conditions?
The MAX4081FAUA-T exhibits no phase reversal when overdriven and recovers from saturation in 50µs (typ). Its output is internally clamped to not exceed 18V, protecting downstream circuitry. During overcurrent, VOUT saturates near VCC (for charge) or GND (for discharge), and returns linearly once VSENSE re-enters range. This behavior is characterized and guaranteed across −40°C to +125°C, ensuring predictable fault response in the MAX4081FAUA-T's target applications.
MAX4081FAUA-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:
- Current Sense
- Number of Circuits:
- 1
- Output Type:
- -
- Slew Rate:
- -
- Gain Bandwidth Product:
- -
- -3db Bandwidth:
- 150 kHz
- Current - Input Bias:
- 5 µA
- Voltage - Input Offset:
- 100 µV
- Current - Supply:
- 103µA
- Current - Output / Channel:
- -
- Voltage - Supply Span (Min):
- 4.5 V
- Voltage - Supply Span (Max):
- 76 V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-uMAX/uSOP
MAX4081FAUA-T FAQ
1.How can I place an order for MAX4081FAUA-T through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX4081FAUA-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 MAX4081FAUA-T reliable?
The price and inventory of MAX4081FAUA-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX4081FAUA-T is usually 5 days.
3.What payment methods are accepted for MAX4081FAUA-T?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX4081FAUA-T transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX4081FAUA-T?
MAX4081FAUA-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX4081FAUA-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 MAX4081FAUA-T?
For technical support, including MAX4081FAUA-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX4081FAUA-T requirements.
6.How does Aetrix verify that MAX4081FAUA-T is sourced from the original manufacturer or authorized distributors?
All MAX4081FAUA-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 MAX4081FAUA-T meets industry standards.
7.What is the process for return or replacement of MAX4081FAUA-T?
All MAX4081FAUA-T units undergo pre-shipment inspection (PSI). If there is an issue with MAX4081FAUA-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 MAX4081FAUA-T part is unused and in its original packaging.
Return procedure for MAX4081FAUA-T:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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