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Texas Instruments LM51581QRTERQ1
- Part No.:
- LM51581QRTERQ1
- Manufacturer:
- Texas Instruments
- Package:
- 16-WFQFN Exposed Pad
- Datasheet:
-
LM51581QRTERQ1.pdf
- Description:
- IC REG BOOST FLYBACK ADJ 16WQFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,258
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Product details
Overview
LM51581QRTERQ1 from Texas Instruments is an AEC-Q100 Grade 1 automotive-qualified, non-synchronous boost/SEPIC/flyback DC-DC controller with integrated 85-V, 1.63-A N-channel MOSFET. It operates from 3.2 V to 60 V input (65-V abs max), delivers up to 83-V output (85-V abs max), supports 100 kHz–2.2 MHz programmable switching frequency, and features dual random spread spectrum for EMI reduction - used in LiDAR power supplies and automotive LED biasing.
For engineers reviewing the LM51581QRTERQ1 datasheet, LM51581QRTERQ1 pinout, LM51581QRTERQ1 application, or LM51581QRTERQ1 equivalent, key selection criteria include its 1.63-A peak current limit (vs. 3.26-A LM5158-Q1), 133-mΩ rDS(ON) at 12 V, ±1% FB reference accuracy, 2.6-µA shutdown IQ, and WQFN-16 (3 mm × 3 mm) wettable flanks package for automotive thermal and reliability requirements.
Technical Context
The LM51581QRTERQ1 implements peak-current-mode control with dynamically programmable switching frequency (100 kHz–2.2 MHz via RT resistor) and selectable dual random spread spectrum to suppress narrowband EMI peaks across wide spectra. Its internal 85-V, 1.63-A MOSFET enables compact high-voltage topologies without external switch drivers.
It supports three operating modes via MODE pin configuration: hiccup + spread spectrum, hiccup only, spread spectrum only, or neither - enabling flexible fault response and EMI tuning. The BIAS pin accepts up to 60 V (65-V abs max) for load-dump robustness, while minimum input voltage drops to 1.5 V when BIAS ≥ 3.2 V - critical for cold-crank automotive operation.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.2 V to 60 V (65-V abs max); supports automotive battery transients and cold-crank down to 1.5 V with BIAS ≥ 3.2 V |
| Output Voltage Capability | Up to 83 V (85-V abs max SW pin rating); enables high-voltage LiDAR and LED bias applications |
| Peak Switch Current Limit | 1.63 A (typ); lower than LM5158-Q1's 3.26 A, defining maximum power delivery and inductor sizing |
| rDS(ON) | 133 mΩ at VBIAS = 12 V; determines conduction loss and thermal rise under full-load conditions |
| Feedback Reference Accuracy | ±1% (0.99 V to 1.01 V); ensures precise output regulation across –40°C to +125°C junction temperature |
| Shutdown Quiescent Current | ≤2.6 µA; minimizes battery drain during vehicle sleep mode |
| Switching Frequency Range | 100 kHz to 2.2 MHz (programmable via RT); 2.2-MHz operation avoids AM band and reduces passive size |
Pinout & Package
LM51581QRTERQ1 uses a 16-pin WQFN package (3.00 mm × 3.00 mm) with wettable flanks and exposed thermal pad (EP), optimized for automotive thermal dissipation and solder-joint inspection.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1, 16 PGND | Power ground | Source connection of internal MOSFET; must be low-inductance path to minimize switching noise |
| 2 VCC | VCC regulator output | Supplies internal circuitry and gate driver; requires 1-µF ceramic bypass to PGND |
| 3 BIAS | VCC regulator input | Wide-range supply input (3.2–60 V); enables operation during load dump and cold crank |
| 4 PGOOD | Power-good indicator | Open-drain signal asserting valid output regulation; requires external pull-up for system sequencing |
| 5 RT | Frequency setting | Resistor-to-AGND sets switching frequency from 100 kHz to 2.2 MHz; defines solution size and EMI profile |
| 6 EN/UVLO/SYNC | Enable / UVLO / sync input | Triple-function pin: enable threshold (0.52 V typ), programmable UVLO divider node, or external clock sync input |
| 7 AGND | Analog ground | Reference for feedback, soft-start, and error amplifier; must connect directly to quiet analog ground plane |
| 8 COMP | Error amplifier output | Connects compensation network (R/C) between COMP and AGND to stabilize loop dynamics |
| 9 FB | Feedback input | Inverting input of transconductance amplifier; connects voltage divider to set output voltage in boost/SEPIC/flyback |
| 10 SS | Soft-start programming | Capacitor-to-AGND sets ramp rate of internal reference; prevents inrush current and overshoot |
| 11 MODE | Mode selection | Configures hiccup protection and spread spectrum via resistor divider (e.g., 37.4 kΩ enables both) |
| 13, 14 SW | Switch node | Drain of internal 85-V MOSFET; connects to inductor/transformer; high dv/dt node requiring careful layout |
| 12, 15 NC | No connect | No internal electrical connection; must remain unconnected per datasheet |
| EP | Exposed thermal pad | Must be soldered to large AGND copper area for thermal management and EMI reduction |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 (–40°C to +125°C TA); qualified for safety-critical vehicle subsystems |
| Primary-side regulation support | Integrated error amplifier enables optocoupler-free flyback designs, reducing BOM count and cost |
| Dual random spread spectrum | Selectable EMI reduction technique spreading energy over ±7.8% frequency range - effective across entire 100 kHz–2.2 MHz band |
| Programmable hiccup overload protection | 64-cycle hiccup timer with 8-cycle reset; limits average power during sustained overloads without thermal runaway |
| Accurate line UVLO | Programmable start-up/shutdown thresholds (1.5 V rising, 1.45 V falling) with 5-µA hysteresis current source for stable operation during cranking |
| Low-light-load efficiency | Pulse-skipping mode and 670-µA operating IQ maintain >85% efficiency at 10-mA load in boost topology |
Applications
| Automotive LED Bias Supply | LiDAR High-Voltage Power Supply |
|---|---|
|
Use Scenario: Powers high-brightness LED arrays in adaptive front lighting systems (AFS) with input from 12-V battery subject to load dump and cold-crank transients. IC Role / Device Role / Timing Role: Non-synchronous boost controller regulating 48-V LED string from 6–16-V battery rail using primary-side sensing. Use Value: 83-V output capability and 65-V abs max BIAS withstand enable direct integration without external TVS; 2.2-MHz operation allows <10-mm² solution size. |
Use Scenario: Generates stable 60–80-V bias for avalanche photodiode (APD) arrays in automotive long-range LiDAR modules. IC Role / Device Role / Timing Role: SEPIC converter delivering regulated high-voltage output from noisy 12-V vehicle bus with minimal EMI impact on sensitive analog receivers. Use Value: Dual random spread spectrum reduces peak EMI by >10 dBµV in 150-kHz–30-MHz CISPR 25 band; ±1% FB reference ensures APD gain stability across temperature. |
| Automotive Voltage Stabilizer (SEPIC) | Hold-Up Capacitor Charger |
|
Use Scenario: Maintains constant 12-V output during engine cranking events where battery sags to 6 V for up to 15 seconds. IC Role / Device Role / Timing Role: Automotive-grade SEPIC controller with BIAS pin supplied from stabilized 12-V rail, enabling operation down to 1.5-V input. Use Value: Programmable UVLO (1.5 V rising) and 2.6-µA shutdown IQ prevent brownout-induced resets while minimizing parasitic drain on backup capacitors. |
Use Scenario: Charges large hold-up capacitors (≥1000 µF) to 48 V after main power-up, sustaining downstream converters during brief AC mains interruptions. IC Role / Device Role / Timing Role: Boost converter operating in constant-current mode during charge phase, then transitioning to constant-voltage regulation. Use Value: Accurate 1.63-A current limit enables predictable charge time; PGOOD signal confirms capacitor voltage reaches 95% target before system release. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage boost/SEPIC controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5158QRTERQ1 | Higher 3.26-A peak current limit; identical pinout, package, and feature set | Supports higher-power boost/SEPIC designs (e.g., >25-W LED drivers); requires larger inductor and MOSFET stress margin | Select LM5158QRTERQ1 when output power exceeds 15 W or peak inductor current >1.4 A. |
| LM5122MQDDAQ1 | Synchronous boost controller (external high-side/low-side FETs); 65-V max SW rating; no integrated MOSFET | Enables >90% efficiency at high loads; requires external gate drivers and layout complexity; lacks spread spectrum | Choose LM5122MQDDAQ1 for efficiency-critical >30-W applications where board space permits discrete FETs and drivers. |
Compared with LM5158QRTERQ1, LM51581QRTERQ1 trades peak current capacity for tighter thermal design and lower gate drive losses in mid-power automotive converters; versus LM5122MQDDAQ1, it offers lower BOM count and integrated EMI mitigation but sacrifices peak efficiency and voltage headroom.
Availability
LM51581QRTERQ1 is available at Aetrix Electronics and suitable for automotive LED biasing, LiDAR high-voltage power supplies, and hold-up capacitor charging requiring stable component supply with AEC-Q100 compliance and long-term production support.
Supply support for LM51581QRTERQ1 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 automotive ICs, with decades of automotive qualification expertise and functional safety documentation support.
The LM5158x-Q1 product line delivers wide-input, high-voltage DC-DC controllers for automotive subsystems demanding robustness against load dump, cold crank, and EMI constraints - targeting LiDAR, ADAS lighting, and infotainment power rails.
FAQ
What is the maximum output voltage supported by the LM51581QRTERQ1?
The LM51581QRTERQ1 supports a maximum output voltage of 83 V under steady-state conditions, with the SW pin rated for 85 V absolute maximum during transients. This enables use in high-voltage applications such as LiDAR bias supplies and multi-string automotive LED drivers without external voltage clamping.
How does the MODE pin configure hiccup protection and spread spectrum on the LM51581QRTERQ1?
The MODE pin on the LM51581QRTERQ1 selects operating mode via resistor-to-AGND: 37.4 kΩ enables both hiccup mode and spread spectrum; 62.0 kΩ enables hiccup only; 100 kΩ enables spread spectrum only; grounding disables both. This allows designers to tailor fault response and EMI performance per application requirements.
Can the LM51581QRTERQ1 operate below 3.2 V input voltage?
Yes - the LM51581QRTERQ1 can operate with input supply voltage as low as 1.5 V when the BIAS pin is supplied ≥3.2 V, such as from a boosted output rail or auxiliary supply. This capability is essential for maintaining functionality during automotive cold-crank events where battery voltage dips below 6 V.
What is the purpose of the EN/UVLO/SYNC pin on the LM51581QRTERQ1?
The EN/UVLO/SYNC pin on the LM51581QRTERQ1 serves three functions: enabling/disabling the device (VEN = 0.52 V typ), programming input undervoltage lockout thresholds via a resistor divider, and synchronizing the internal oscillator to an external clock signal - providing flexibility in power sequencing, transient immunity, and system-level EMI coordination.
Does the LM51581QRTERQ1 require an external optocoupler in flyback configurations?
No - the LM51581QRTERQ1 integrates a transconductance error amplifier and supports primary-side regulation (PSR) in flyback topologies, eliminating the need for an optocoupler and secondary-side TL431. This reduces component count, improves reliability, and simplifies layout in isolated automotive power supplies.
LM51581QRTERQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Boost, Flyback, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.5V
- Voltage - Input (Max):
- 60V
- Voltage - Output (Min/Fixed):
- 1.5V
- Voltage - Output (Max):
- 83V
- Current - Output:
- 1.63A (Switch)
- Frequency - Switching:
- 100kHz ~ 2.2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-WQFN (3x3)
LM51581QRTERQ1 FAQ
1.How can I place an order for LM51581QRTERQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for LM51581QRTERQ1 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 LM51581QRTERQ1 reliable?
The price and inventory of LM51581QRTERQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM51581QRTERQ1 is usually 5 days.
3.What payment methods are accepted for LM51581QRTERQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM51581QRTERQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM51581QRTERQ1?
LM51581QRTERQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM51581QRTERQ1 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 LM51581QRTERQ1?
For technical support, including LM51581QRTERQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM51581QRTERQ1 requirements.
6.How does Aetrix verify that LM51581QRTERQ1 is sourced from the original manufacturer or authorized distributors?
All LM51581QRTERQ1 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 LM51581QRTERQ1 meets industry standards.
7.What is the process for return or replacement of LM51581QRTERQ1?
All LM51581QRTERQ1 units undergo pre-shipment inspection (PSI). If there is an issue with LM51581QRTERQ1, 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 LM51581QRTERQ1 part is unused and in its original packaging.
Return procedure for LM51581QRTERQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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