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Texas Instruments LM25019SDX/NOPB
- Part No.:
- LM25019SDX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-WDFN Exposed Pad
- Datasheet:
-
LM25019SDX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 100MA 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:2,282
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Product details
Overview
LM25019SDX/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 adjustable output voltage from 1.225 V. It delivers isolated bias supply in telecom systems using Fly-Buck™ topology.
For engineers reviewing the LM25019SDX/NOPB datasheet, LM25019SDX/NOPB pinout, LM25019SDX/NOPB application, or LM25019SDX/NOPB equivalent, key selection criteria include input voltage range (7.5–48 V), COT-based transient response, programmable undervoltage lockout, thermal shutdown, and dual-package availability (WSON-8 and SO PowerPAD-8).
Technical Context
The LM25019SDX/NOPB implements constant on-time control with VIN-dependent on-time (via RON resistor), enabling near-constant switching frequency across 7.5–48 V input and eliminating need for external compensation. Its intelligent peak current limit uses FB-voltage–dependent off-time to reduce foldback during overload while maintaining short-circuit protection.
It integrates a 7.6-V internal VCC regulator with 4.5-V UVLO, bootstrap gate drive (BST–SW capacitor required), and dual-level UVLO circuitry allowing independent programming of enable threshold (1.225 V) and shutdown threshold (0.66 V) via external resistive divider on UVLO pin.
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% - sets precise output voltage via external resistor divider (VOUT = 1.225 × (1 + RFB2/RFB1)) |
| Switching Frequency | Adjustable up to 1 MHz - set by RON resistor and VIN; typical 240 kHz at 48 V input |
| Current Limit Threshold | 150–370 mA - peak-limited protection with FB-dependent off-time for adaptive overload recovery |
| Thermal Shutdown | 165°C activation with 20°C hysteresis - prevents catastrophic failure under sustained overtemperature |
| Package Options | 8-pin WSON (4.0 mm × 4.0 mm) and 8-pin SO PowerPAD™ (4.89 mm × 3.90 mm) - both thermally enhanced with exposed pad |
Pinout & Package
LM25019SDX/NOPB is available in two thermally optimized packages: 8-pin WSON (NGU) and 8-pin SO PowerPAD™ (DDA), both featuring an exposed thermal pad that must be soldered to PCB ground plane for effective heat dissipation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 RTN | Ground reference | Primary GND connection for IC substrate and feedback network; exposed pad must connect to same net |
| 2 VIN | Main power input | Accepts 7.5–48 V; powers internal VCC regulator and high-voltage gate drivers |
| 3 UVLO | Undervoltage detection input | Enables/locks out operation based on external resistor divider; 0.66 V shutdown, 1.225 V enable |
| 4 RON | On-time programming | Resistor to VIN sets minimum on-time; determines switching frequency and ensures ≥100 ns at 48 V |
| 5 FB | Feedback input | Compares against 1.225 V reference; ripple amplitude ≥25 mV required for stable COT operation |
| 6 VCC | Internal bias supply output | 7.6 V regulated output for gate drivers; requires 1.0-μF decoupling capacitor |
| 7 BST | Bootstrap supply node | Connects to SW via 0.01-μF ceramic capacitor; recharged during SW low phase via internal diode |
| 8 SW | Power switching node | Drives external inductor; connects to BST capacitor and output filter; handles full switching current |
Key Features
| Feature | Design Value |
|---|---|
| Constant On-Time (COT) Control | Eliminates need for external compensation components and enables ultra-fast load transient response |
| Integrated High- and Low-Side MOSFETs | Reduces BOM count and layout complexity; eliminates external Schottky diode in buck mode |
| Fly-Buck™ Topology Support | Enables isolated output generation without optocoupler or transformer feedback winding |
| Programmable UVLO with Hysteresis | Allows custom input voltage start-up and brownout thresholds using two external resistors |
| Intelligent Peak Current Limit | Adapts off-time based on FB voltage to minimize foldback and improve recovery from moderate overloads |
Applications
| Industrial Power Supplies | Telecom Bias Rails |
|---|---|
Use Scenario: Regulating 48-V backplane to 5-V or 3.3-V auxiliary rail in programmable logic controllers and sensor nodes. IC Role / Device Role / Timing Role: Primary synchronous buck controller managing power conversion, thermal management, and fault protection. Use Value: Enables compact, high-efficiency local regulation without external compensation or Schottky diode, reducing board area and component count. | Use Scenario: Generating isolated -5-V or +12-V bias for RS-485 transceivers and Ethernet PHYs in 48-V telecom equipment. IC Role / Device Role / Timing Role: Fly-Buck™ isolated DC-DC controller providing galvanically separated secondary outputs. Use Value: Delivers reliable isolation without optocoupler or third winding, simplifying transformer design and improving startup consistency. |
| Smart Meter Auxiliary Power | Isolated Gate Driver Supply |
Use Scenario: Powering metrology ADC, real-time clock, and RF module from 24-V or 48-V utility meter main rail. IC Role / Device Role / Timing Role: Low-quiescent, high-input-voltage buck regulator with remote shutdown for energy-saving sleep modes. Use Value: Maintains stable 3.3-V output across wide input range while drawing only 50–225 µA in shutdown-critical for battery-backed operation. | Use Scenario: Providing isolated +15 V/-8 V gate drive supply for IGBTs in motor drives or inverters. IC Role / Device Role / Timing Role: Fly-Buck™ controller delivering tightly regulated, low-noise isolated bias with fast transient response. Use Value: Ensures robust gate drive under dynamic load conditions without requiring complex snubbers or additional regulators. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck/Fly-Buck™ regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5160QDGSRQ1 | Automotive-grade AEC-Q100 qualified; wider temp range (−40°C to 150°C); higher 65-V max input | Designed for automotive infotainment and ADAS power rails; includes spread-spectrum and enhanced EMI features | Choose for automotive safety-critical designs requiring qualification and extended temperature operation |
| LM250118SDX/NOPB | Same family, pin-compatible; higher 200-mA output current; identical COT architecture and package footprint | Direct upgrade path where >100 mA load current is required; shares same layout and support components | Choose when higher output current is needed without redesigning PCB or changing control strategy |
Compared with LM5160QDGSRQ1 and LM250118SDX/NOPB, the LM25019SDX/NOPB offers optimal cost-performance balance for industrial and telecom non-automotive applications, with verified Fly-Buck™ capability, minimal external parts, and proven thermal performance in SO PowerPAD™ and WSON packages.
Availability
LM25019SDX/NOPB is available at Aetrix Electronics and suitable for industrial power supplies, telecom bias rails, and smart meter auxiliary power requiring stable component supply and long-term manufacturability.
Supply support for LM25019SDX/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 broad industrial and automotive portfolio coverage.
The LM25019 belongs to TI's high-voltage DC-DC regulator product line, designed specifically for efficient, compact, and robust power conversion in 24-V and 48-V systems including industrial automation, communications infrastructure, and energy metering.
FAQ
What is the maximum input voltage rating for LM25019SDX/NOPB?
The absolute maximum input voltage (VIN to RTN) for LM25019SDX/NOPB is 53 V, but the recommended operating range is 7.5 V to 48 V. Operation above 48 V risks exceeding thermal limits due to increased VCC regulator dissipation and may trigger overvoltage protection on internal nodes like BST–SW (max 13 V) or SW–RTN (transient max VIN + 0.3 V). Always observe derating guidelines per Section 6.1 of the LM25019SDX/NOPB datasheet.
Does LM25019SDX/NOPB require an external Schottky diode?
No, LM25019SDX/NOPB does not require an external Schottky diode because it integrates both high-side and low-side N-channel MOSFETs for synchronous rectification. This eliminates conduction losses associated with diode forward voltage drop and improves efficiency-especially at light loads-while enabling continuous conduction mode (CCM) operation across all load conditions.
How is the switching frequency set on LM25019SDX/NOPB?
The switching frequency of LM25019SDX/NOPB is set by the resistor connected between RON pin and VIN. The on-time (TON) is inversely proportional to VIN and RON value, resulting in nearly constant frequency across input voltage variations. For example, with RON = 100 kΩ and VIN = 48 V, TON ≈ 250 ns, yielding ~400 kHz; lower RON increases frequency, but minimum on-time must remain ≥100 ns for reliable operation.
Can LM25019SDX/NOPB be used in Fly-Buck™ topology?
Yes, LM25019SDX/NOPB is explicitly designed and characterized for Fly-Buck™ operation, enabling isolated output generation without optocoupler feedback. Its constant on-time control, integrated synchronous switches, and robust current limiting make it suitable for generating ±5 V, ±12 V, or other isolated bias rails from a single 24-V or 48-V input-common in telecom, industrial I/O, and gate driver applications.
What thermal considerations apply to LM25019SDX/NOPB in SO PowerPAD™ package?
In the SO PowerPAD™ (DDA) package, LM25019SDX/NOPB has RθJA = 41.1°C/W and RθJC(bot) = 2.4°C/W. To maintain junction temperature ≤125°C, ensure the exposed pad is fully soldered to a minimum 1-in² copper pour connected to RTN. At 100 mA output and 48-V input, thermal simulation shows ~3.5 W total dissipation; proper PCB copper area and airflow prevent thermal shutdown activation at ambient ≤70°C.
LM25019SDX/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)
LM25019SDX/NOPB FAQ
1.How can I place an order for LM25019SDX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM25019SDX/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 LM25019SDX/NOPB reliable?
The price and inventory of LM25019SDX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM25019SDX/NOPB is usually 5 days.
3.What payment methods are accepted for LM25019SDX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM25019SDX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM25019SDX/NOPB?
LM25019SDX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM25019SDX/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 LM25019SDX/NOPB?
For technical support, including LM25019SDX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM25019SDX/NOPB requirements.
6.How does Aetrix verify that LM25019SDX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM25019SDX/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 LM25019SDX/NOPB meets industry standards.
7.What is the process for return or replacement of LM25019SDX/NOPB?
All LM25019SDX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM25019SDX/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 LM25019SDX/NOPB part is unused and in its original packaging.
Return procedure for LM25019SDX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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