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Texas Instruments LM5181QNGURQ1
- Part No.:
- LM5181QNGURQ1
- Manufacturer:
- Texas Instruments
- Package:
- 8-WDFN Exposed Pad
- Datasheet:
-
LM5181QNGURQ1.pdf
- Description:
- IC REG FLYBACK ADJ 750MA 8WSON
- Quantity:
- Payment:
- Shipping:
Inventory:3,303
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Product details
Overview
LM5181QNGURQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive primary-side regulated (PSR) flyback DC/DC controller with integrated 100-V, 0.75-A N-channel MOSFET, 4.5–65-V input range, ±1.5% output regulation accuracy, and boundary conduction mode (BCM) operation for isolated bias supplies in traction inverters and gate drivers.
For engineers reviewing the LM5181QNGURQ1 datasheet, LM5181QNGURQ1 pinout, LM5181QNGURQ1 application, or LM5181QNGURQ1 equivalent, key selection considerations include PSR-based optocoupler-free isolation, thermal-compensated feedback via TC pin, programmable soft start, hiccup-mode overcurrent protection, and WSON-8 wettable flanks package for automotive-grade reflow inspection.
Technical Context
The LM5181QNGURQ1 implements variable-frequency peak current-mode (VFPCM) control with three operating modes: BCM at heavy loads (up to 350 kHz), DCM at mid loads (clamped max frequency), and frequency foldback mode (FFM) at light loads (down to 12 kHz). It samples reflected flyback voltage at secondary zero-current crossing to achieve precise primary-side regulation without optocoupler or auxiliary winding.
Its integrated 100-V/0.4-Ω MOSFET supports up to 4 W output power, while internal loop compensation, ±1.5% total output regulation, and optional VOUT temperature compensation via TC–RSET resistor network enable robust performance across –40°C to +125°C ambient.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 65 V - supports wide automotive battery transients including cold-crank (down to 3.5 V post-startup) |
| Output Regulation Accuracy | ±1.5% - includes line, load, and temperature variation; enables stable gate driver bias without secondary sensing |
| Integrated Power Switch | 100-V, 0.75-A N-channel MOSFET - eliminates external high-voltage switch; RDS(on) = 0.4 Ω at TJ = 25°C |
| Switching Frequency Range | 12 kHz to 350 kHz - adaptive VFPCM enables high efficiency across full load range without external frequency setting |
| Soft Start | 6-ms internal or externally programmable - controlled via SS/BIAS pin capacitor; prevents input inrush during power-up |
| Thermal Protection | 175°C shutdown with 6°C hysteresis - automatic recovery after cooling; ensures reliability in enclosed HEV/EV enclosures |
| Package | 8-pin WSON (4.0 mm × 4.0 mm) with wettable flanks - supports automated optical inspection (AOI) for automotive PCB assembly |
Pinout & Package
LM5181QNGURQ1 is housed in an 8-pin WSON package (NGU) with 0.8-mm pin pitch and exposed die attach pad (DAP) connected to GND. Wettable flanks enable solder joint inspection per IPC-A-610.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - SW | Switch node | Internally connected to MOSFET drain; connects to primary winding of flyback transformer; handles up to 100-V transient spikes |
| 2 - FB | Primary-side feedback input | Senses reflected flyback voltage; ratio of FB-to-SW resistor vs RSET sets output voltage; no optocoupler required |
| 3 - VIN | Power input | Bias supply source and input voltage sense node; supports 4.5–65-V operation with UVLO monitoring |
| 4 - EN/UVLO | Enable & UVLO programming | Three-state logic: <1.1 V = shutdown, 1.1–1.5 V = standby, >1.5 V = active; hysteresis enables clean power sequencing |
| 5 - SS/BIAS | Soft start / external bias input | Capacitor sets soft-start time; >5.5 V enables external bias for lower quiescent current and higher efficiency |
| 6 - TC | Temperature compensation | Connects to RSET to offset diode VF drift; improves output regulation stability over –40°C to +125°C |
| 7 - RSET | Reference current setting | 12.1-kΩ to GND sets 100-µA reference current and 1.21-V internal reference; defines output voltage scaling |
| 8 - GND | Analog & power ground | Common return for control circuitry and MOSFET source; DAP must be soldered to PCB ground plane |
Key Features
| Feature | Design Value |
|---|---|
| Primary-side regulation (PSR) | Eliminates optocoupler, TL431, and transformer auxiliary winding - reduces BOM count and improves long-term reliability in safety-critical systems |
| Boundary conduction mode (BCM) | Enables zero-current switching on secondary side - minimizes diode reverse recovery loss and EMI, meeting CISPR 25 Class 5 |
| Integrated 100-V MOSFET | Supports 65-V automotive input with headroom for load dump (ISO 7637-2 Pulse 5a); reduces layout complexity and footprint |
| Hiccup-mode overcurrent protection | Shuts down on sustained overload, then auto-restarts - protects against shorted gate driver outputs without latch-off |
| AEC-Q100 Grade 1 qualification | Validated for –40°C to +125°C ambient operation - suitable for under-hood and powertrain applications including IGBT/SiC gate drivers |
Applications
| Automotive Traction Inverter Bias Supply | Isolated IGBT Gate Driver Power |
|---|---|
Use Scenario: Provides isolated 5-V/0.5-A bias rail inside high-voltage traction inverter modules for SiC/IGBT gate drivers. IC Role / Device Role / Timing Role: PSR flyback controller regulating output from primary side; replaces optocoupler-based solutions with single-component isolation barrier. Use Value: Enables compact, high-reliability bias generation with ±1.5% regulation across temperature and line - critical for consistent gate drive timing and shoot-through prevention. | Use Scenario: Powers dual isolated gate drivers in HEV/EV motor control units where space and thermal constraints limit discrete solutions. IC Role / Device Role / Timing Role: Primary-side regulated flyback converter delivering stable 5-V output; uses BCM switching to minimize EMI near sensitive gate drive signals. Use Value: Achieves >85% efficiency at 500 mA with ultra-low radiated emissions - avoids interference with PWM timing and current sensing circuits. |
| Sub-AM Band Body Electronics | Factory Automation Isolated Sensors |
Use Scenario: Supplies isolated 5-V power to LIN bus transceivers and door module MCUs in 12-V/24-V vehicle architectures. IC Role / Device Role / Timing Role: Automotive-grade PSR flyback IC with programmable UVLO and thermal shutdown - ensures robust startup during cold-crank conditions. Use Value: Operates down to 3.5 V post-startup and withstands 65-V transients - eliminates need for pre-regulator stage in body control modules. | Use Scenario: Generates isolated 5-V supply for analog sensor front-ends in industrial PLC I/O modules requiring reinforced insulation. IC Role / Device Role / Timing Role: Compact flyback controller with internal compensation and wettable-flank WSON package - simplifies certified isolation design and AOI validation. Use Value: Delivers 4-W output in 4 mm × 4 mm footprint with ±1.5% regulation - reduces board area versus discrete transformer + regulator solutions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar PSR flyback controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC28911DR | 65-V max input, no integrated MOSFET (external FET required), fixed 70-kHz frequency, no TC pin | Lacks thermal compensation and programmable soft start; suited for cost-sensitive non-automotive applications | Choose UCC28911DR only if external MOSFET selection and simplified thermal design are acceptable trade-offs |
| LM5021MMX/NOPB | Requires optocoupler feedback, 100-V input, no integrated MOSFET, no PSR capability | Needs secondary-side sensing components; not AEC-Q100 qualified; higher solution size and component count | Select LM5021MMX/NOPB only when legacy optocoupler-based architecture or non-automotive qualification suffices |
Compared with UCC28911DR and LM5021MMX/NOPB, the LM5181QNGURQ1 delivers superior integration (integrated 100-V MOSFET), automotive qualification (AEC-Q100 Grade 1), and precision regulation (±1.5% with TC compensation), making it the optimal choice for space-constrained, safety-critical isolated bias supplies.
Availability
LM5181QNGURQ1 is available at Aetrix Electronics and suitable for automotive traction inverters, isolated gate driver power supplies, and sub-AM band body electronics requiring stable component supply, long lifecycle support, and AEC-Q100 compliance.
Supply support for LM5181QNGURQ1 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 company specializing in analog and embedded processing technologies, with leadership in power management ICs for automotive, industrial, and communications markets.
The LM5181-Q1 product line delivers highly integrated, AEC-Q100-qualified PSR flyback controllers targeting isolated bias supplies in electric vehicle powertrain systems, traction inverters, and automotive body electronics.
FAQ
What is the maximum output power supported by the LM5181QNGURQ1?
The LM5181QNGURQ1 supports up to 4 W of isolated output power using its integrated 100-V, 0.75-A MOSFET. This is validated across the full 4.5–65-V input range and –40°C to +125°C ambient, with efficiency exceeding 85% at 500 mA output into a 5-V rail. The LM5181QNGURQ1 achieves this with boundary conduction mode (BCM) operation and optimized thermal design in its WSON-8 package.
Does the LM5181QNGURQ1 require an optocoupler for output regulation?
No, the LM5181QNGURQ1 does not require an optocoupler. It implements primary-side regulation (PSR) by sampling the reflected flyback voltage at the SW pin during secondary zero-current crossing. This eliminates the need for optocouplers, TL431 references, or auxiliary transformer windings - reducing component count, improving reliability, and simplifying certification for reinforced isolation in automotive applications.
How is output voltage set on the LM5181QNGURQ1?
The output voltage of the LM5181QNGURQ1 is set by the resistor divider between SW and FB pins, referenced to the internal 1.21-V bandgap established by the 12.1-kΩ RSET-to-GND resistor. For a 5-V output, typical values are RFB = 158 kΩ and RSET = 12.1 kΩ. The LM5181QNGURQ1 also supports optional temperature compensation via the TC pin to correct for diode forward-voltage drift across temperature.
What protection features are built into the LM5181QNGURQ1?
The LM5181QNGURQ1 includes hiccup-mode overcurrent protection, thermal shutdown with 6°C hysteresis (triggering at 175°C junction), input UVLO with programmable hysteresis, and MOSFET overcurrent limiting at 0.75-A peak. These protections operate autonomously without external components and ensure safe recovery after fault clearance - critical for automotive gate driver bias rails where latch-off could disable powertrain control.
Can the LM5181QNGURQ1 operate with an external bias supply?
Yes, the LM5181QNGURQ1 supports external bias via the SS/BIAS pin. When voltage exceeds 5.5 V, the internal LDO switches to external sourcing, reducing active quiescent current from 350 µA to 40 µA and improving light-load efficiency. This is commonly implemented using a transformer auxiliary winding, and the LM5181QNGURQ1 includes dedicated circuitry to manage bias sequencing and soft-start ramp control under external bias conditions.
LM5181QNGURQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-WDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Flyback
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 65V
- Voltage - Output (Min/Fixed):
- 0V
- Voltage - Output (Max):
- 100V
- Current - Output:
- 750mA
- Frequency - Switching:
- 12kHz ~ 350kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-WSON (4x4)
LM5181QNGURQ1 FAQ
1.How can I place an order for LM5181QNGURQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM5181QNGURQ1 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 LM5181QNGURQ1 reliable?
The price and inventory of LM5181QNGURQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM5181QNGURQ1 is usually 5 days.
3.What payment methods are accepted for LM5181QNGURQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM5181QNGURQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM5181QNGURQ1?
LM5181QNGURQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM5181QNGURQ1 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 LM5181QNGURQ1?
For technical support, including LM5181QNGURQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM5181QNGURQ1 requirements.
6.How does Aetrix verify that LM5181QNGURQ1 is sourced from the original manufacturer or authorized distributors?
All LM5181QNGURQ1 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 LM5181QNGURQ1 meets industry standards.
7.What is the process for return or replacement of LM5181QNGURQ1?
All LM5181QNGURQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LM5181QNGURQ1, 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 LM5181QNGURQ1 part is unused and in its original packaging.
Return procedure for LM5181QNGURQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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