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Texas Instruments LM25019SDE/NOPB
- Part No.:
- LM25019SDE/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-WDFN Exposed Pad
- Datasheet:
-
LM25019SDE/NOPB.pdf
- Description:
- IC REG BUCK ADJ 100MA 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:300
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Product details
Overview
LM25019SDE/NOPB from Texas Instruments is a 48-V, 100-mA synchronous buck/Fly-Buck™ regulator with integrated high-side and low-side N-channel MOSFETs, constant on-time (COT) control, no loop compensation required, and 1.225-V precision feedback reference. It delivers isolated bias supply in telecom systems using Fly-Buck™ topology.
For engineers reviewing the LM25019SDE/NOPB datasheet, LM25019SDE/NOPB pinout, LM25019SDE/NOPB application, or LM25019SDE/NOPB equivalent, key selection criteria include input voltage range (7.5–48 V), adjustable switching frequency up to 1 MHz via RON, thermal shutdown at 165°C, remote shutdown capability, and dual-package availability (WSON-8 and SO PowerPAD-8).
Technical Context
The LM25019SDE/NOPB implements a constant on-time (COT) control architecture where on-time is inversely proportional to VIN and set by an external RON resistor, enabling near-constant frequency operation across 7.5–48 V input. Its intelligent peak current limit uses a forced off-time inversely proportional to FB voltage for short-circuit protection with minimal foldback.
It integrates a 7.6-V internal VCC regulator with 4.5-V UVLO, bootstrap gate drive with 0.01-μF BST–SW capacitor, and dual-level undervoltage detection (0.66 V shutdown, 1.225 V enable) programmable via external divider. No external Schottky diode is needed due to synchronous rectification.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 7.5 V to 48 V - supports industrial 24-V and telecom 48-V rails without pre-regulation |
| Output Current | 100 mA - sufficient for isolated bias supplies and low-power auxiliary rails |
| Feedback Reference | 1.225 V ±2% - enables precise output voltage setting with external resistor divider |
| Switching Frequency | Adjustable up to 1 MHz - set via RON; higher frequencies reduce inductor size but increase switching loss |
| Thermal Shutdown | 165°C with 20°C hysteresis - protects against sustained overload or poor PCB thermal design |
| Current Limit Threshold | 150–370 mA (typ. 270 mA) - peak-limited protection with adaptive off-time to minimize foldback |
| VCC Regulator Output | 7.6 V ±1.3 V - powers internal logic and gate drivers; disabled if externally supplied 8.55–13 V applied |
Pinout & Package
LM25019SDE/NOPB is available in two thermally enhanced packages: 8-pin WSON (4.00 mm × 4.00 mm) and 8-pin SO PowerPAD™ (4.89 mm × 3.90 mm), both featuring an exposed thermal pad soldered to RTN for improved heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 RTN | Ground reference | Primary GND connection; exposed pad must be soldered to system ground plane |
| 2 VIN | Main power input | Accepts 7.5–48 V; powers internal VCC regulator and high-voltage gate driver |
| 3 UVLO | Undervoltage lockout input | Programmable shutdown threshold (0.66 V) and enable threshold (1.225 V) via resistor divider |
| 4 RON | On-time programming | Resistor between RON and VIN sets minimum on-time and thus operating frequency |
| 5 FB | Feedback input | Compares to 1.225-V internal reference; requires ≥25 mV ripple for stable COT operation |
| 6 VCC | Bias supply output | 7.6-V regulated output for internal circuitry; requires 1.0-μF decoupling capacitor |
| 7 BST | Bootstrap supply | Charged via internal diode from VCC during SW low-phase; drives high-side gate |
| 8 SW | Switching node | Connects to inductor and BST capacitor; carries full switching current and voltage stress |
Key Features
| Feature | Design Value |
|---|---|
| Constant on-time (COT) control | Eliminates need for external compensation network; enables ultra-fast transient response and high step-down ratios |
| Synchronous buck + Fly-Buck™ topology | Enables isolated output generation without optocoupler or transformer auxiliary winding-ideal for bias supplies |
| No external Schottky diode required | Integrated low-side MOSFET replaces lossy diode, improving efficiency and reducing BOM count |
| Intelligent peak current limit | Adaptive off-time reduces foldback during moderate overloads, speeding recovery and start-up |
| Remote shutdown via UVLO pin | 0.66-V threshold allows system-level power sequencing and fault-initiated disable |
Applications
| Industrial Equipment Power | Smart Power Meter Bias Supply |
|---|---|
Use Scenario: Providing 5-V or 12-V auxiliary rail in PLC I/O modules or motor drives operating from 24-V DC bus. IC Role / Device Role / Timing Role: Primary synchronous buck regulator delivering stable 100-mA output with fast load-step response. Use Value: Eliminates need for external compensation and Schottky diode, reducing solution size and cost while maintaining >90% efficiency at full load. | Use Scenario: Generating isolated 3.3-V bias for metrology ICs and communication interfaces inside revenue-grade electricity meters. IC Role / Device Role / Timing Role: Fly-Buck™ converter providing galvanically isolated output without optocoupler or third winding. Use Value: Achieves <1% output voltage drift over temperature and line, meeting IEC 62053 accuracy requirements for auxiliary supplies. |
| Telecom 48-V System Bias | Isolated Gate Driver Supply |
Use Scenario: Deriving 12-V isolated supply for PoE PD controllers or Ethernet PHYs in 48-V telecom infrastructure equipment. IC Role / Device Role / Timing Role: Input-direct buck regulator accepting full 48-V nominal rail with 10% tolerance and surge immunity. Use Value: Operates reliably across 7.5–48 V input range without input pre-regulator, simplifying front-end design and improving system efficiency. | Use Scenario: Powering high-side gate drivers in half-bridge inverters where floating supply is required for level-shifting. IC Role / Device Role / Timing Role: Fly-Buck™ configuration generating negative or positive isolated rail referenced to switch node. Use Value: Delivers clean, low-noise isolated supply with <100-mVpp ripple, ensuring robust gate drive timing and minimizing shoot-through risk. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5164SDE/NOPB | Higher 100-V input rating, 600-mA output, requires external compensation; larger package (10-pin WSON) | Used in automotive or industrial HVDC systems requiring >48 V input; not drop-in compatible | Select when input exceeds 48 V or output current >100 mA is required; board redesign needed |
| TPS54160DGQ | 60-V input, 1.5-A output, current-mode control, integrated compensation; different pinout and control scheme | Targets higher-power DC/DC conversion with tighter regulation; lacks Fly-Buck™ capability | Choose for higher output current or when loop compensation is preferred; not functionally interchangeable |
Compared with LM5164SDE/NOPB and TPS54160DGQ, LM25019SDE/NOPB offers unique Fly-Buck™ isolation capability, zero-compensation COT operation, and optimized 100-mA output for space-constrained bias supplies-making it the only choice for compact isolated auxiliary rails in 48-V telecom and metering designs.
Availability
LM25019SDE/NOPB is available at Aetrix Electronics and suitable for industrial equipment power, smart power meter bias supply, and telecom 48-V system bias requiring stable component supply and long-term manufacturability.
Supply support for LM25019SDE/NOPB 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in high-reliability power conversion solutions.
The LM25019SDE/NOPB belongs to TI's high-voltage DC/DC regulator product line, designed specifically for efficient, compact, isolated and non-isolated bias supply generation in industrial, telecom, and energy metering applications.
FAQ
What is the maximum input voltage rating for LM25019SDE/NOPB?
The absolute maximum input voltage (VIN to RTN) for LM25019SDE/NOPB is 53 V, but its recommended operating range is 7.5 V to 48 V. Operation above 48 V risks exceeding thermal limits and degrading reliability. The device is rated for continuous 48-V input, making it suitable for standard telecom and industrial DC rails. Always observe derating guidelines per Section 6.1 of the LM25019SDE/NOPB datasheet.
Does LM25019SDE/NOPB support Fly-Buck™ topology out of the box?
Yes, LM25019SDE/NOPB natively supports Fly-Buck™ operation without additional ICs or optocouplers. Its synchronous buck architecture, combined with COT control and precise timing, enables stable isolated output generation using a coupled inductor. TI provides validated reference designs (e.g., TIDA-01482) demonstrating ±1% regulation and <100-mVpp ripple in Fly-Buck™ mode. No firmware or external feedback compensation is required for basic implementation.
What is the purpose of the RON pin on LM25019SDE/NOPB?
The RON pin on LM25019SDE/NOPB sets the minimum on-time via an external resistor connected to VIN, directly determining switching frequency. For example, a 100-kΩ resistor yields ~250 ns on-time at 48 V input and ~240 kHz operation. RON must be selected so minimum on-time exceeds 100 ns at max VIN to ensure reliable gate drive. This pin enables frequency adjustment without changing inductor or capacitor values-critical for EMI optimization and layout reuse.
Can LM25019SDE/NOPB operate without an external bootstrap capacitor?
No, LM25019SDE/NOPB requires a 0.01-μF ceramic capacitor between BST and SW pins. This capacitor supplies gate drive voltage for the high-side N-channel MOSFET during on-time. Without it, the high-side switch fails to turn on fully, causing excessive conduction loss, thermal runaway, and potential device failure. TI specifies X7R or better dielectric and recommends placement within 2 mm of the BST/SW pins to minimize parasitic inductance.
How does the current limit protection work in LM25019SDE/NOPB?
LM25019SDE/NOPB implements intelligent peak current limiting: when inductor current exceeds 270 mA (typ.), the on-time is immediately terminated and a non-resettable off-time begins. That off-time duration depends on FB voltage and VIN-shorter for light overloads (e.g., 2 μs at VFB = 1 V), longer for shorts (e.g., 16 μs at VFB = 0 V). This adaptive behavior minimizes output voltage sag and accelerates recovery, unlike fixed-foldback limiters. The feature is fully internal and requires no external components.
LM25019SDE/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-WDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 7.5V
- Voltage - Input (Max):
- 48V
- Voltage - Output (Min/Fixed):
- 1.225V
- Voltage - Output (Max):
- 40V
- Current - Output:
- 100mA
- Frequency - Switching:
- Up to 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-WSON (4x4)
LM25019SDE/NOPB FAQ
1.How can I place an order for LM25019SDE/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM25019SDE/NOPB 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 LM25019SDE/NOPB reliable?
The price and inventory of LM25019SDE/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM25019SDE/NOPB is usually 5 days.
3.What payment methods are accepted for LM25019SDE/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM25019SDE/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM25019SDE/NOPB?
LM25019SDE/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM25019SDE/NOPB 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 LM25019SDE/NOPB?
For technical support, including LM25019SDE/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM25019SDE/NOPB requirements.
6.How does Aetrix verify that LM25019SDE/NOPB is sourced from the original manufacturer or authorized distributors?
All LM25019SDE/NOPB 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 LM25019SDE/NOPB meets industry standards.
7.What is the process for return or replacement of LM25019SDE/NOPB?
All LM25019SDE/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM25019SDE/NOPB, 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 LM25019SDE/NOPB part is unused and in its original packaging.
Return procedure for LM25019SDE/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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