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STMicroelectronics L99LD02Q505TR
- Part No.:
- L99LD02Q505TR
- Manufacturer:
- STMicroelectronics
- Category:
- DC DC Switching Controllers
- Package:
- 32-VFQFN Exposed Pad
- Datasheet:
-
L99LD02Q505TR.pdf
- Description:
- DUAL-PHASE BOOST DC/DC CONTROLLE
- Quantity:
- Payment:
- Shipping:
Inventory:2,838
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Product details
Overview
L99LD02Q505TR from STMicroelectronics is an AEC-Q100 qualified automotive dual-phase boost DC/DC controller in QFN32L 5×5 package, driving N-channel MOSFETs via two independent gate drivers (GO1/GO2), supporting up to 80 V regulated output with programmable 100–470 kHz switching frequency and integrated 10 V LDO for standard-level MOSFET gate drive - used in high-brightness LED module power supplies for vehicle lighting systems.
For engineers reviewing the L99LD02Q505TR datasheet, L99LD02Q505TR pinout, L99LD02Q505TR application, or L99LD02Q505TR equivalent, this page delivers verified technical context, SPI-configurable boost control parameters, multi-phase synchronization capability, cold-cranking robustness, and Limp Home stand-alone operation details essential for automotive LED driver design and qualification.
Technical Context
The L99LD02Q505TR implements peak current mode control with programmable input current limitation, adjustable slope compensation, and constant voltage regulation across two interleaved boost phases. Its ST SPI v4.1 interface enables full configuration of operating frequency, phase shift, error amplifier gain, and protection thresholds without external component changes.
It integrates a 10 V LDO for gate driver supply, supports device self-powering from BST_OUT during low-battery cold cranking, and features SYNC_I/O for master/slave clock distribution across up to four phases. Thermal warning, overvoltage protection (OVP), and input overcurrent protection are all SPI-programmable and validated per AEC-Q100 Grade 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3 V to 28 V - enables direct battery connection with reverse polarity protection and cold-cranking support down to 3 V. |
| Boost Output Voltage | Up to 80 V - sufficient to drive 60 V LED strings in automotive headlamp and DRL applications. |
| Switching Frequency | 100–470 kHz, programmable via SPI - allows EMI optimization and inductor size reduction while maintaining stable current-mode control. |
| Gate Driver Supply | Integrated 10 V LDO - directly drives standard-level N-channel MOSFETs without external level-shifting circuitry. |
| Multi-phase Support | Up to 4-phase interleaving via SYNC_I/O - reduces input/output ripple, cuts filter component size, and improves thermal distribution. |
| Protection Features | Programmable input OCP, thermal shutdown, OVP, and VS under-voltage lockout - ensures fail-safe operation in harsh automotive environments. |
| Communication Interface | ST SPI v4.1 (CSN/SCK/SDI/SDO) - provides real-time diagnostics, register readback, and robust protocol failure detection including clock monitor and data-stuck checks. |
Pinout & Package
Package: QFN32L 5×5 mm with exposed thermal pad (PGND-connected), RoHS-compliant, moisture sensitivity level MSL3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GO1, GO2 | Gate driver outputs | Drive external N-channel MOSFET gates with 10 V swing; each controls one boost phase independently. |
| SP1/SN1, SP2/SN2 | Current sense inputs | Differential inputs for shunt resistor connections - enable per-phase peak current mode control and balanced current sharing. |
| COMP | Error amplifier output | Connects external RC compensation network to stabilize voltage loop; sets transient response and stability margin. |
| SYNC_I/O | Multi-phase clock I/O | Configurable as master (generates phase-shifted clocks) or slave (accepts external sync); enables precise interleaving across multiple devices. |
| V10V | 10 V LDO output | Supplies gate drivers; requires local 1 µF low-ESR capacitor for noise immunity and transient response. |
| V3V3A / V3V3D | 3.3 V logic supply outputs | Power internal digital circuitry and SPI interface; must be decoupled with 1 µF capacitor near each pin. |
| VS | Main supply input | Connects to battery via Schottky diode; powers internal regulators and analog blocks - rated for 3–28 V operation. |
| TM | Standby/Limp Home control | Direct microcontroller I/O or fail-safe logic input to enter/exit standby or activate Limp Home mode without SPI communication. |
Key Features
| Feature | Design Value |
|---|---|
| Stand-alone Limp Home operation | Fully configurable via OTP bits - enables safe degraded-mode operation (e.g., reduced LED brightness) after MCU failure or SPI loss. |
| Dither oscillator | Programmable frequency modulation and deviation % via SPI - reduces conducted EMI peaks without altering average switching frequency. |
| Soft-start | Controlled ramp-up of output voltage - prevents inrush current and stress on LEDs, MOSFETs, and input capacitors at power-on. |
| Timeout watchdog | Monitored SPI activity counter - triggers Limp Home or reset if host communication stalls, enhancing system safety integrity. |
| Cold-cranking guarantee | Full boost functionality maintained at VS = 3 V - meets ISO 16750-2 Pulse 4 requirement for engine start conditions. |
Applications
| Automotive Headlamp Systems | Daytime Running Light (DRL) Modules |
|---|---|
|
Use Scenario: High-power white LED arrays in adaptive front-lighting systems requiring stable >60 V output and thermal resilience. IC Role / Device Role / Timing Role: Dual-phase boost controller regulating output voltage while balancing current between two parallel LED strings via interleaved switching. Use Value: Reduces output capacitor RMS current by ~70% vs. single-phase, lowering temperature rise and extending electrolytic capacitor lifetime in under-hood environments. |
Use Scenario: Compact, thermally constrained DRL modules mounted in bumper or grille with limited PCB area and airflow. IC Role / Device Role / Timing Role: Stand-alone boost controller operating in Limp Home mode when MCU is inactive - maintains basic illumination using pre-programmed OTP settings. Use Value: Eliminates need for backup MCU or secondary regulator, reducing BOM count and enabling ASIL-B compliant functional safety architecture. |
| LED Fog Lamp Drivers | Commercial Vehicle Lighting Control |
|
Use Scenario: 24 V truck/bus fog lamps driving long LED strings demanding high efficiency and input voltage resilience down to 12 V. IC Role / Device Role / Timing Role: Dual-phase controller with programmable input current limit - dynamically adjusts peak current to maintain constant LED brightness across wide battery range (12–28 V). Use Value: Enables consistent lumen output during alternator load dump (ISO 7637-2 Pulse 5a) and cold-cranking (3 V), critical for regulatory compliance. |
Use Scenario: Centralized lighting control unit powering multiple LED zones (tail, brake, turn) in heavy-duty vehicles with CAN-based diagnostics. IC Role / Device Role / Timing Role: SPI-configurable boost stage providing isolated, stabilized voltage rails for downstream LED drivers and sensor interfaces. Use Value: Allows software-defined reconfiguration of output voltage and protection thresholds across vehicle variants - reducing SKU proliferation and validation effort. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-phase boost controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5122MQ/NOPB | Single-phase controller with external clock sync; no integrated 10 V LDO or Limp Home mode. | Requires external gate driver and failsafe logic; lacks AEC-Q100 qualification and cold-cranking support below 5 V. | Choose for cost-sensitive non-automotive industrial boost designs where SPI configurability and fail-safe operation are not required. |
| MAX20077ATP/VY+ | Single-output, single-phase automotive boost controller with integrated MOSFETs; fixed 2.2 MHz frequency. | Not scalable beyond 12 A output; no multi-phase stacking or programmable frequency; limited to lower-power LED applications. | Choose only for space-constrained, low-power (<25 W) LED drivers where board area is prioritized over flexibility and scalability. |
Compared with LM5122MQ/NOPB and MAX20077ATP/VY+, the L99LD02Q505TR uniquely combines dual-phase interleaving, SPI-driven configurability, cold-cranking down to 3 V, and certified Limp Home operation - making it the only option qualified for ASIL-B LED lighting systems requiring functional safety and multi-kW scalability.
Availability
L99LD02Q505TR is available at Aetrix Electronics and suitable for automotive LED lighting, headlamp control units, and commercial vehicle lighting systems requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.
Supply support for L99LD02Q505TR 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing automotive-grade ICs, power management solutions, and microcontrollers for safety-critical applications.
The L99LD02 belongs to ST's Automotive Power Switching & LED Driver product line, engineered specifically for high-reliability, multi-string LED power conversion in vehicle lighting - emphasizing functional safety, thermal robustness, and software-defined configurability.
FAQ
What is the purpose of the TM pin on the L99LD02Q505TR?
The TM (Test Mode) pin serves as a direct hardware control input for entering standby or activating Limp Home mode without SPI communication. It can be driven by a microcontroller GPIO or fail-safe logic circuit, enabling immediate transition to safe operational states during MCU faults or communication loss - critical for ISO 26262 ASIL-B compliance in LED lighting systems.
Can the L99LD02Q505TR operate with only one boost phase active?
Yes - the L99LD02Q505TR supports single-phase operation via SPI configuration. Phase 1 (GO1/SP1/SN1) can be enabled independently while disabling phase 2, allowing flexible design reuse across different power tiers. The device maintains full protection, regulation, and diagnostic functionality in single-phase mode, with identical input/output specifications.
How does the SYNC_I/O pin enable multi-phase operation?
The SYNC_I/O pin operates in master or slave mode: as master, it generates a programmable clock with configurable phase shift for synchronizing additional L99LD02 devices; as slave, it accepts an external clock signal. This enables precise interleaving across up to four phases, reducing input/output ripple and improving thermal distribution without external timing components.
Is the 10 V LDO on the L99LD02Q505TR capable of driving external logic circuits?
No - the V10V pin is dedicated solely to powering the internal gate drivers for external N-channel MOSFETs. It is not rated for general-purpose logic supply and lacks current capability or regulation stability for digital ICs. External logic must be powered separately via V3V3A/V3V3D (3.3 V) or an external regulator.
L99LD02Q505TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 32-VFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Type:
- Transistor Driver
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Number of Outputs:
- 1
- Output Phases:
- 2
- Voltage - Supply (Vcc/Vdd):
- 3V ~ 28V
- Frequency - Switching:
- 100kHz ~ 470kHz
- Duty Cycle (Max):
- 95%
- Synchronous Rectifier:
- No
- Clock Sync:
- Yes
- Serial Interfaces:
- SPI
- Control Features:
- Current Limit, Enable
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount, Wettable Flank
- Supplier Device Package:
- 32-QFN (5x5)
L99LD02Q505TR FAQ
1.How can I place an order for L99LD02Q505TR through Aetrix?
Please submit a Request for Quotation (RFQ) for L99LD02Q505TR 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 L99LD02Q505TR reliable?
The price and inventory of L99LD02Q505TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L99LD02Q505TR is usually 5 days.
3.What payment methods are accepted for L99LD02Q505TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L99LD02Q505TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L99LD02Q505TR?
L99LD02Q505TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L99LD02Q505TR 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 L99LD02Q505TR?
For technical support, including L99LD02Q505TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L99LD02Q505TR requirements.
6.How does Aetrix verify that L99LD02Q505TR is sourced from the original manufacturer or authorized distributors?
All L99LD02Q505TR 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 L99LD02Q505TR meets industry standards.
7.What is the process for return or replacement of L99LD02Q505TR?
All L99LD02Q505TR units undergo pre-shipment inspection (PSI). If there is an issue with L99LD02Q505TR, 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 L99LD02Q505TR part is unused and in its original packaging.
Return procedure for L99LD02Q505TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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