Key Selection Information
| Selection Parameter | Confirmed Information |
|---|---|
| Topologies | Boost, SEPIC and flyback with external low-side N-FET |
| Input | 2.97 V to 48 V |
| Frequency | 100 kHz to 1 MHz adjustable and externally synchronizable |
| Gate Drive | 1 A peak push-pull driver |
| Control | Current-mode with cycle-by-cycle programmable current limit |
| UVLO | Adjustable undervoltage lockout with hysteresis |
| Light Load | Pulse-skipping behavior supported |
| Exact Package / Packing | VSSOP (DGS), 10 pins; 3500-piece large reel; −40°C to +125°C; marking SJPB |
Product Overview
LM3481MMX/NOPB is the higher-input, more configurable evolution of the LM3478-style low-side controller. It extends VIN to 48 V, adds external clock synchronization and provides adjustable UVLO and pulse-skipping features.
Synchronization can align converter switching to a system clock or move power-supply noise away from sensitive frequency bands. Adjustable UVLO is useful when source batteries or industrial rails must not be loaded below a chosen threshold.
Like LM3478, the controller relies on an external MOSFET and external magnetics, so power rating and switch stress come from the complete topology rather than an IC wattage number.
For related devices, see HKEQGOO’s DC DC Switching Controllers category.
Technical Specifications
| Parameter | Verified Information |
|---|---|
| Manufacturer | Texas Instruments |
| Exact MPN | LM3481MMX/NOPB |
| Topologies | Boost, SEPIC and flyback with external low-side N-FET |
| Input | 2.97 V to 48 V |
| Frequency | 100 kHz to 1 MHz adjustable and externally synchronizable |
| Gate Drive | 1 A peak push-pull driver |
| Control | Current-mode with cycle-by-cycle programmable current limit |
| UVLO | Adjustable undervoltage lockout with hysteresis |
| Light Load | Pulse-skipping behavior supported |
| Exact Package / Packing | VSSOP (DGS), 10 pins; 3500-piece large reel; −40°C to +125°C; marking SJPB |
| Manufacturer Status | Active / Production |
| Part Marking | SJPB |
Functional Highlights
48-V input headroom fits telecom and wider industrial rails
The additional VIN range gives more transient/nominal margin than a 40-V controller, though surge protection may still be required.
External synchronization improves EMI/system clock planning
Multiple converters can avoid uncontrolled beat frequencies or align switching away from measurement/audio bands.
Design Considerations
- Use adjustable UVLO to protect the source from deep discharge or unstable low-line operation.
- Account for pulse-skipping spectral behavior at light load if the application is noise sensitive.
- Select external MOSFET and diode voltage ratings from boost/flyback switch stress, not the 48-V VIN value alone.
Product Status and Exact Order Code
Texas Instruments lists LM3481MMX/NOPB as Active / Production; VSSOP (DGS), 10 pins; 3500-piece large tape and reel; −40°C to +125°C; marking SJPB.
Related Engineering Resources
Quality & Verification Support
Third-party inspection or testing can be arranged according to customer requirements. Testing fees are borne by the buyer. Additional verification requirements can be discussed before shipment. After an order is placed, physical product, label, packaging, and Date Code photos may be provided where appropriate.
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To request a quotation, provide the manufacturer part number, required quantity, destination, target Date Code if applicable, and any testing or inspection requirements.
For a related 8-pin VSSOP current-mode boost, SEPIC or flyback controller with a higher maximum specified input voltage, compare LM3478MMX/NOPB (2.97–40 V input and up to 100% duty cycle) with this LM3481MMX/NOPB (2.97–48 V input and 85% maximum duty cycle). TI also lists adjustable UVLO on LM3481. Verify transformer or inductor operating point, attainable duty cycle, pin functions and compensation design rather than assuming these controllers are directly interchangeable.
