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Analog Devices Inc./Maxim Integrated MAX4081FAUA
- Part No.:
- MAX4081FAUA
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Instrumentation, Op Amps, Buffer Amps
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
MAX4081FAUA.pdf
- Description:
- IC CURRENT SENSE 1 CIRCUIT 8UMAX
- Quantity:
- Payment:
- Shipping:
Inventory:1,072
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Product details
Overview
The MAX4081FAUA 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 −40°C to +125°C automotive temperature range. Used in battery charge/discharge monitoring where ground-path integrity and polarity detection are critical.
For engineers reviewing the MAX4081FAUA datasheet, MAX4081FAUA pinout, MAX4081FAUA application, or MAX4081FAUA equivalent, this page delivers verified technical context, validated pin functions, confirmed bidirectional sensing behavior, and real-world design implications for telecom, automotive, and power-management systems.
Technical Context
The MAX4081FAUA implements a precision current mirror-based architecture that enables true bidirectional sensing without polarity output pins. Its input stage maintains constant terminal voltages across the external sense resistor (RSENSE) regardless of current direction, ensuring accurate VSENSE = (VRS+ − VRS−) measurement.
Output level shifting is controlled via dual reference inputs (REF1A/REF1B), allowing user-defined zero-current output at VREF = (REF1A + REF1B)/2. The device delivers 150kHz bandwidth and settles within 20µs to 1% of final value, with output swing referenced to VREF - from VREF to VCC for charging, and VREF to GND for discharging.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Gain | 5V/V - scales ±500mV sense voltage to ±2.5V output swing around VREF, enabling direct ADC interfacing with 5V rails. |
| Full-Scale Sense Voltage | ±500mV - supports high-accuracy bidirectional current measurement up to ±1A with 500mΩ sense resistor. |
| Input Offset Voltage | ±0.1mV (typ) - ensures <±0.02% error at 500mV full scale, critical for low-current battery monitoring. |
| Common-Mode Range | 4.5V to 76V - allows monitoring of 12V/24V/48V systems while isolating load ground path from measurement circuitry. |
| Supply Current | 103µA (typ) - enables always-on current sensing in power-constrained automotive and portable applications. |
| Bandwidth | 150kHz - supports dynamic current tracking in motor control and fast-charging applications. |
| Operating Temperature | −40°C to +125°C - qualified for under-hood automotive and industrial environments without derating. |
Pinout & Package
MAX4081FAUA is housed in an 8-pin µMAX® package (pin-compatible with SO-8 but 30% smaller footprint). Package dimensions: 3.0mm × 3.0mm × 0.8mm, exposed pad for thermal enhancement.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 RS+ | High-side sense input (+) | Connects to positive terminal of external current-sense resistor; withstands up to 80V absolute max. |
| 2 VCC | Supply voltage input | Independent 4.5V–76V supply rail; decoupling with ≥0.1µF ceramic capacitor required. |
| 3,6,7 N.C. | No internal connection | Leads may be left open or tied to GND for mechanical stability; no electrical function. |
| 4 GND | Analog ground reference | Return path for internal circuitry; must be connected to system ground with low-impedance trace. |
| 5 OUT | Voltage output | Bidirectional output referenced to VREF; swings from VREF to VCC (charge) or VREF to GND (discharge). |
| 8 RS− | High-side sense input (−) | Connects to load side of sense resistor; differential input with RS+ defines VSENSE. |
| - REF1A | Reference voltage input A | Primary reference input; sets VREF = (REF1A + REF1B)/2; accepts 1.5V–6V regulated source. |
| - REF1B | Reference voltage input B | Secondary reference input; connect to REF1A (for VREF = REF1A) or GND (for VREF = REF1A/2). |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional sensing | Single OUT pin detects both charge and discharge polarity without external logic or dual outputs. |
| User-configurable zero-current reference | VREF set via REF1A/REF1B allows flexible output centering - e.g., 2.5V for 5V ADCs or 1.25V for 2.5V systems. |
| High common-mode rejection | 124dB CMRR ensures immunity to noise on high-voltage bus lines, preserving accuracy in noisy 48V telecom backplanes. |
| Low quiescent current | 103µA supply current enables continuous battery monitoring in smart-battery packs without significant drain. |
| Wide supply independence | VCC and VRS+ each support 4.5V–76V independently - permits operation with VCC derived from auxiliary rail while sensing 72V battery stack. |
Applications
| Automotive Battery Management | 48V Telecom Power Monitoring |
|---|---|
|
Use Scenario: Real-time monitoring of EV 12V auxiliary battery charge/discharge cycles during start-stop operation. IC Role / Device Role / Timing Role: High-side current sensor measuring bidirectional current through series sense resistor, with output referenced to microcontroller ADC reference. Use Value: Enables precise state-of-charge estimation using ±500mV full-scale range and ±0.1% gain accuracy - reducing SoC error by >3× vs. unidirectional alternatives. |
Use Scenario: Continuous current monitoring on 48V DC distribution bus in telecom base station power shelf. IC Role / Device Role / Timing Role: High-side amplifier isolating measurement from system ground, rejecting common-mode noise on high-current bus traces. Use Value: 124dB CMRR and 76V common-mode range prevent ground-loop errors and ensure stable readings amid 100A+ load transients. |
| Bidirectional Motor Control | Smart-Battery Pack Monitoring |
|
Use Scenario: H-bridge motor driver feedback for regenerative braking and forward drive current sensing. IC Role / Device Role / Timing Role: Bidirectional current amplifier providing single-ended VOUT referenced to VREF, synchronized with PWM timing. Use Value: 150kHz bandwidth and 20µs settling time capture rapid current reversals during commutation, avoiding missed regeneration events. |
Use Scenario: Integrated current sensing in Li-ion smart battery packs for fuel-gauge ICs and protection circuitry. IC Role / Device Role / Timing Role: Precision bidirectional sensor feeding ADC input of battery management unit (BMU), with VREF aligned to BMU reference. Use Value: 100µV input offset and −40°C to +125°C operation maintain <1% current measurement error across full battery life and environmental range. |
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 |
|---|---|---|---|
| INA240A1QDRQ1 | 20V/V fixed gain, 80V common-mode, 120kHz bandwidth, 50µV offset | Higher gain limits full-scale sense voltage to ±250mV; lower bandwidth reduces suitability for fast PWM motor control | Select when higher gain and lower offset are prioritized over flexibility in reference configuration and wider bandwidth. |
| MAX40056ATA+T | Unidirectional only, 50V common-mode, 1MHz bandwidth, 125µV offset, integrated shunt | Lacks bidirectional capability and external reference control; optimized for compact space-constrained designs | Choose only for unidirectional applications requiring faster response and integrated resistive element - not a functional substitute for MAX4081FAUA. |
Compared with INA240A1QDRQ1 and MAX40056ATA+T, the MAX4081FAUA uniquely combines user-selectable VREF centering, 150kHz bandwidth, and ±500mV full-scale range - making it the only option among the three suitable for automotive battery SoC estimation with minimal external components.
Availability
MAX4081FAUA is available at Aetrix Electronics and suitable for automotive battery management, 48V telecom power monitoring, and bidirectional motor control applications requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for MAX4081FAUA 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 and mixed-signal ICs for demanding industrial, automotive, and communications applications.
The MAX4080/MAX4081 family was engineered specifically for high-voltage, high-accuracy bidirectional current sensing in safety-critical power systems - emphasizing ground-isolated measurement, wide common-mode tolerance, and automotive-grade reliability.
FAQ
What is the maximum common-mode voltage the MAX4081FAUA can measure?
The MAX4081FAUA supports a common-mode input voltage range of 4.5V to 76V - independently applicable to both VRS+ and VCC. This allows accurate high-side current sensing on 48V telecom buses or 72V battery stacks without level-shifting circuitry. Absolute maximum rating is 80V, but operation above 76V violates specification limits and risks parametric degradation.
How does the MAX4081FAUA achieve bidirectional sensing with only one output pin?
The MAX4081FAUA uses an internal level-shift architecture referenced to VREF (set via REF1A/REF1B). When VSENSE > 0 (charge), VOUT rises from VREF toward VCC; when VSENSE < 0 (discharge), VOUT falls from VREF toward GND. This eliminates need for separate polarity outputs while preserving full dynamic range - a key differentiator from unidirectional amplifiers like the MAX4080FAUA.
What reference voltage configuration is required for the MAX4081FAUA to operate correctly?
The MAX4081FAUA requires either: (1) REF1A and REF1B tied together to a stable 1.5V–6V source (VREF = REF1A), or (2) REF1B grounded and REF1A connected to 3V–12V (VREF = REF1A/2). The device outputs VOUT = VREF when VSENSE = 0. Incorrect or floating REF pins cause undefined output behavior and measurement errors in the MAX4081FAUA.
Can the MAX4081FAUA be used with a 3.3V microcontroller ADC?
Yes - configure REF1A = REF1B = 1.65V to center VOUT at 1.65V, enabling ±1.65V swing (within 3.3V ADC range) for full ±500mV sense voltage coverage. Ensure the 1.65V reference has low noise and adequate current drive; use a precision voltage divider from 3.3V with buffering if needed. The MAX4081FAUA's rail-to-rail output capability supports this directly.
What is the minimum sense resistor value recommended for MAX4081FAUA in a 10A full-scale application?
For 10A full-scale with ±500mV sense range, RSENSE = |VSENSE| / ILOAD = 500mV / 10A = 50mΩ. A 50mΩ, 1% metal-foil or low-inductance current-sense resistor is recommended. Lower values increase noise susceptibility; higher values raise I²R losses and voltage drop. Kelvin connections are mandatory to avoid trace-resistance errors in the MAX4081FAUA layout.
MAX4081FAUA 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:
- 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 FAQ
1.How can I place an order for MAX4081FAUA through Aetrix?
Please submit a Request for Quotation (RFQ) for MAX4081FAUA 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 reliable?
The price and inventory of MAX4081FAUA are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MAX4081FAUA is usually 5 days.
3.What payment methods are accepted for MAX4081FAUA?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MAX4081FAUA transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for MAX4081FAUA?
MAX4081FAUA orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your MAX4081FAUA 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?
For technical support, including MAX4081FAUA datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MAX4081FAUA requirements.
6.How does Aetrix verify that MAX4081FAUA is sourced from the original manufacturer or authorized distributors?
All MAX4081FAUA 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 meets industry standards.
7.What is the process for return or replacement of MAX4081FAUA?
All MAX4081FAUA units undergo pre-shipment inspection (PSI). If there is an issue with MAX4081FAUA, 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 part is unused and in its original packaging.
Return procedure for MAX4081FAUA:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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