LM3481QMMX/NOPBQ1 - 48V Boost/SEPIC/Flyback Controller | TI
MPN: LM3481QMMX/NOPBQ1 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.6 | $260.00 |
| 500 | $2.25 | $1,125.00 |
| 1,000 | $1.95 | $1,950.00 |
Drop-in alternatives for LM3481QMMX/NOPBQ1 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
LM3481QMM/NOPB
β Drop-Inπ Reference alternative (not in catalog)
LM3481MMX/NOPB
β Drop-Inβ In Stock
$0.6 / Unit
View Datasheet βLM3481QMY/NOPB
β Drop-Inπ Reference alternative (not in catalog)
LM5117QMHX/NOPBQ1
β‘ Same Packageβ In Stock
$3.72 / Unit
View Datasheet βMAX668AUB
β‘ Same Packageπ Reference alternative (not in catalog)
LM3481QMMX/NOPBQ1 Maximum Ratings & Electrical Characteristics
| Topology | Boost, SEPIC, Flyback |
| Control Method | Current Mode PWM |
| Input Voltage Range | 2.97 V to 48 V |
| Output Polarity | Positive |
| Switch Type | External Low-Side N-Channel FET |
| Maximum Switching Frequency | 1 MHz (resistor programmable) |
| Maximum Duty Cycle | 85% |
| Number of Outputs | 1 |
| Automotive Qualification | AEC-Q100 Grade 1 |
| Operating Temperature | -40C to +125C |
| Package | 10-VSSOP / 10-MSOP (3.00mm width) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (TR) |
| Protection Features | Cycle-by-cycle current limit, thermal shutdown |
| RoHS Status | Compliant (NOPB / lead-free) |
| Gate Driver Supply | Internal regulated VCC for N-FET drive |
LM3481QMMX/NOPBQ1 Pin Configuration
| Pin 1 | SW β Switch node connection to external N-FET drain |
| Pin 2 | VCC β Internal regulated supply output for gate drive |
| Pin 3 | GND β Ground reference |
| Pin 4 | FB β Feedback input from output voltage divider |
| Pin 5 | COMP β Loop compensation network connection |
| Pin 6 | FREQ β Switching frequency set resistor |
| Pin 7 | SS β Soft-start capacitor connection |
| Pin 8 | VIN β Input supply, 2.97V to 48V |
| Pin 9 | CS β Current sense input for cycle-by-cycle limit |
| Pin 10 | AGND β Analog ground for controller reference |
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this component. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
LM3481QMMX/NOPBQ1 is suitable for 6 applications: Automotive LED Headlamp Driver, Automotive Infotainment Display Boost Rail, On-Board Charger Auxiliary Supply, Industrial 24V Boost Converter, SEPIC Battery-Power Conversion, Gateway and Telematics Power Stage.
Automotive LED Headlamp Driver
The LM3481-Q1 fits automotive LED headlamp boost stages because its 2.97V to 48V VIN absorbs load-dump transients and its AEC-Q100 Grade 1 rating covers the -40C to +125C engine-bay environment. Operating in boost mode with an external low-side N-FET, it steps 12V up to the LED string voltage; cycle-by-cycle current limit plus the current-mode loop enable constant-current LED drive, and 1MHz-capable operation keeps the inductor small for lamp housings.
Recommended
Automotive Infotainment Display Boost Rail
Infotainment panels require a stable 12V-to-18V or higher boost rail from the car battery. The LM3481-Q1 drives an external MOSFET, allowing designers to scale output current to the display backlight and logic load without being limited by an internal switch. Its current-mode PWM with 85% duty cycle and resistor-programmable frequency (up to 1MHz) lets the converter sit above the AM band to ease EMI filtering, while AEC-Q100 Grade 1 qualification meets cabin temperature requirements.
Recommended
On-Board Charger Auxiliary Supply
EV on-board chargers need an auxiliary rail powered from the high-voltage DC link. The LM3481-Q1's 48V maximum VIN and flyback topology support make it a fit for tapping intermediate 12V/24V/48V buses to generate isolated or non-isolated auxiliary supplies for gate drivers and contactors. Using an external N-FET lets the design handle tens of watts, and thermal shutdown plus cycle-by-cycle current limit provide robust fault handling in high-voltage environments.
Recommended
Industrial 24V Boost Converter
Industrial control and instrumentation running from 24V buses frequently need 36V to 48V rails for sensors, OLED displays, or op-amp supplies. The LM3481-Q1 boosts from 24V with ample headroom, and its wide VIN also tolerates 12V fallback operation. The current-mode loop simplifies loop compensation with ceramic output capacitors, and the VSSOP-10 footprint keeps the controller overhead small on dense industrial PCBs.
Recommended
SEPIC Battery-Power Conversion
For battery-powered equipment where the input varies above and below the required output, the LM3481-Q1 SEPIC configuration regulates a fixed output from a 3-cell to 4-cell series battery. Its low 2.97V minimum VIN supports deeply discharged cells, while the coupled-inductor SEPIC topology with an external low-side FET delivers efficient step-up/step-down conversion. Programmable frequency up to 1MHz permits small coupled inductors in portable and robotics designs.
Recommended
Gateway and Telematics Power Stage
Automotive gateway and telematics modules generate 5V or 8V intermediate rails from a fluctuating 9V to 16V battery input. The LM3481-Q1 in boost mode with pre-boost for cold crank keeps downstream bucks such as the LM5176 or TPS65 family powered during voltage dips. Its small VSSOP-10 package and high switching frequency reduce board area, and AEC-Q100 Grade 1 qualification supports the telematics unit's under-dash temperature profile.
Recommended
Recommended Products Summary
Engineering reference data for LM3481QMMX/NOPBQ1 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LM3481QMM/NOPB | LM3481MMX/NOPB | MAX668AUB |
|---|---|---|---|---|
| Package | VSSOP-10 (DGS) | VSSOP-10 (DGS) - same | VSSOP-10 (DGS) - same | MSOP-10 - same footprint, different pinout |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Analog Devices |
| Input Voltage Range | 2.97 V to 48 V | 2.97 V to 48 V | 2.97 V to 48 V | 3 V to 28 V |
| Topologies | Boost, SEPIC, Flyback | Boost, SEPIC, Flyback | Boost, SEPIC, Flyback | Boost, SEPIC, Flyback |
| Max Switching Frequency | 1 MHz | 1 MHz | 1 MHz | 500 kHz |
| Max Duty Cycle | 85% | 85% | 85% | [DATA_NEEDED] |
| Automotive Qualification | AEC-Q100 Grade 1 | AEC-Q100 Grade 1 | Not automotive qualified | Not automotive qualified |
| Control Method | Current Mode PWM | Current Mode PWM | Current Mode PWM | Current Mode PWM |
| Pin-to-Pin Drop-In | N/A (reference) | Yes - identical | Yes - identical | No - redesign required |
Key Differentiators
- AEC-Q100 Grade 1 automotive qualification (vs LM3481MMX/NOPB)
- Wider 48V VIN than cross-brand MSOP-10 controllers (vs MAX668AUB)
- Scalable output power via external FET (vs LM5117QMHX/NOPBQ1)
Design Notes
Keep the power loop (input cap, external N-FET, inductor, sense resistor) as tight as possible; the SW node carries high dv/dt and radiates. Route the CS sense line differentially to the sense resistor Kelvin contacts to avoid false current-limit trips from switch-node ringing. Place the FREQ, FB, and COMP components close to their pins with a solid analog ground return to pin 10.
In boost converters the output is connected to VIN through the inductor when the FET fails short, so add reverse protection or a fuse if the load must be protected. Ensure VCC (internal regulator) has the recommended decoupling capacitor or gate drive collapses at high frequency. Never exceed the 48V absolute maximum VIN - automotive load dump requires upstream TVS suppression.
Because this is a controller, thermal design centers on the external MOSFET and sense resistor, not the VSSOP-10 itself. Size the FET for RMS current and switching loss at your frequency; at 1MHz, switching loss dominates, so choose a FET with low Qgd. Verify sense resistor power: P = I^2 x R, and derate at 125C ambient for AEC-Q1 designs.
Compliance Information
NOPB suffix indicates No Pb (lead-free) per TI ordering nomenclature. AEC-Q100 Grade 1 per TI LM3481-Q1 product page. REACH and halogen-free status not stated in provided data.
