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STMicroelectronics L99ASC03TR
- Part No.:
- L99ASC03TR
- Manufacturer:
- STMicroelectronics
- Category:
- Motor Drivers, Controllers
- Package:
- 48-TQFP Exposed Pad
- Datasheet:
-
L99ASC03TR.pdf
- Description:
- IC MOTOR DRIVER 6V-28V 48TQFP
- Quantity:
- Payment:
- Shipping:
Inventory:1,914
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Product details
Overview
L99ASC03TR from STMicroelectronics is an automotive-qualified brushless DC (BLDC) sensorless 3-phase motor pre-driver IC. It integrates three half-bridge gate drivers, a 5 V/200 mA voltage regulator, ST SPI interface, window watchdog, BEMF detection IP, and current-sense amplifier - all in a TQFP48-EP package. Designed for engine cooling fans, fuel pumps, and water pumps, it controls six external N-channel MOSFETs down to 6 V supply voltage with programmable overcurrent protection and drain-source monitoring.
For engineers reviewing the L99ASC03TR datasheet, L99ASC03TR pinout, L99ASC03TR application, or L99ASC03TR equivalent, this page delivers verified technical context, real-world motor control use cases, SPI-configurable diagnostics, thermal warning thresholds, and validated alternatives for automotive mechatronic designs.
Technical Context
The L99ASC03TR implements a dual-power architecture with separate VS (motor supply), VSREG (regulator input), and VSMS (motor supply sense) pins, enabling robust operation during cold-crank and load-dump events. Its two-stage charge pump supports 100% duty cycle high-side drive and maintains gate bias down to 6 V input.
Advanced sensorless commutation relies on integrated BEMF detection with configurable sampling timing and stepping logic (BEMFCNT), while the ST SPI interface provides full register-level access to device control, status, and diagnostics - including thermal warnings (TW1/TW2), shutdown flags (TSD1/TSD2), and persistent fault counters for watchdog and thermal events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range (VS) | 5.5 V to 28 V - supports automotive battery transients including cold-crank (down to 6 V during PWM operation). |
| VDD Regulator Output | 5 V ±2%, 200 mA continuous - powers external MCU or sensors without external LDO. |
| Standby Current | 15 µA typ. - enables ultra-low-power VBAT standby mode for always-on automotive subsystems. |
| PWM Frequency Support | Up to 80 kHz - allows high-resolution motor speed control without switching limitation. |
| BEMF Detection Accuracy | Configurable threshold and sampling phase - enables reliable sensorless commutation across wide speed/load ranges. |
| Overcurrent Protection | Programmable via SPI with fast response (< 2 µs) - protects external MOSFETs against short-circuit faults. |
| Thermal Monitoring | Integrated junction temperature sensing with two warning levels (TW1/TW2) and dual shutdown thresholds (TSD1/TSD2). |
Pinout & Package
TQFP48-EP (7 × 7 × 1 mm, 4.5 × 4.5 mm exposed pad) - thermally enhanced package optimized for automotive motor control PCB layouts with high power dissipation requirements.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SL1–SL3 | Low-side MOSFET source terminals | Direct connection points to external low-side FET sources; used for current sensing and open-load detection. |
| IH1–IH3, IL1–IL3 | Gate driver input controls | SPI-configurable logic inputs that define high/low-side switching states and dead-time behavior. |
| GH1–GH3, GL1–GL3 | High/low-side gate driver outputs | Drive external N-MOSFET gates with cross-current protection and adaptive charge pump bias. |
| VS, VSREG, VSMS | Dedicated supply and sense inputs | Independent power domains enable accurate undervoltage/overvoltage monitoring and fail-safe response. |
| AOUT, DOUT, BEMFOUT | Analog/digital multiplexer outputs | Single-pin time-multiplexed reporting of internal temp, supply voltages, and BEMF signals for system diagnostics. |
Key Features
| Feature | Design Value |
|---|---|
| ST SPI Interface | Full-duplex serial interface with 32-bit command frames, diagnostic readback, and register-based configuration - eliminates need for parallel control lines. |
| Two-Stage Charge Pump | Supports 100% duty cycle high-side drive and stable gate bias at VS ≥ 6 V - critical for low-voltage cranking operation. |
| Drain-Source Monitoring | Detects both ON-state short circuits and OFF-state open loads per phase - enables comprehensive MOSFET health monitoring. |
| Window Watchdog | Configurable timeout window with early/late/safe zones - prevents unintended resets while ensuring functional safety compliance. |
| Thermal Warning & Shutdown | Two independent warning thresholds (TW1/TW2) and two shutdown levels (TSD1/TSD2) - allows staged thermal mitigation before catastrophic failure. |
Applications
| Engine Cooling Fan Control | Fuel Pump Drive |
|---|---|
|
Use Scenario: Variable-speed fan control in ICE vehicles using PWM-based thermal management feedback loops. IC Role / Device Role / Timing Role: Pre-driver managing six external MOSFETs in 3-phase bridge; BEMF detection enables sensorless commutation without Hall sensors. Use Value: Reduces BOM cost by eliminating position sensors while maintaining precise speed regulation across 200–12,000 RPM range. |
Use Scenario: High-reliability fuel delivery in gasoline direct injection systems requiring continuous operation under harsh EMI and thermal conditions. IC Role / Device Role / Timing Role: Fault-tolerant gate driver with drain-source monitoring and programmable overcurrent protection per phase. Use Value: Prevents MOSFET failure during line-to-line shorts or clogged filter conditions via sub-2 µs fault response and automatic safe shutdown. |
| Water Pump Actuation | Oil Pump Regulation |
|
Use Scenario: Electric coolant pump in hybrid powertrains where variable flow rate improves thermal efficiency and reduces parasitic loss. IC Role / Device Role / Timing Role: SPI-configurable motor controller with analog multiplexer output (AOUT) for real-time junction temperature and VSMS monitoring. Use Value: Enables closed-loop thermal derating - throttling speed when TJ exceeds TW1 (145 °C) to extend lifetime under sustained high-load conditions. |
Use Scenario: Variable-displacement oil pump in modern engines requiring pressure modulation based on engine speed and load. IC Role / Device Role / Timing Role: Gate driver with disable input (DIS) and INH wake-up capability - supports stop-start cycles and rapid reactivation from VBAT standby mode. Use Value: Achieves 15 µA standby current and < 100 ms wake-up latency - meets OEM requirements for micro-hybrid system energy budgets. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar BLDC pre-driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DRV3205-Q1 | Integrated gate drivers only - no onboard voltage regulator or BEMF detection logic. | Requires external 5 V supply and separate commutation controller (e.g., MCU with BEMF algorithm). | Preferred when system already includes a dedicated motor control MCU and needs minimal external components for gate driving only. |
| MC33883 | Legacy 3-phase pre-driver with fixed-function BEMF comparator - no SPI configurability or multi-level thermal warning. | Limited diagnostics and no analog multiplexer output; requires discrete watchdog and voltage monitor ICs. | Suitable for cost-sensitive legacy platforms where firmware flexibility and advanced diagnostics are not required. |
Compared with DRV3205-Q1 and MC33883, the L99ASC03TR offers integrated power regulation, SPI-based parameter tuning, and granular thermal/fault reporting - reducing system-level component count and enabling OTA-updatable motor control strategies.
Availability
L99ASC03TR is available at Aetrix Electronics and suitable for engine cooling fans, fuel pumps, and water pumps requiring stable component supply in automotive production environments with AEC-Q100 Grade 0 qualification.
Supply support for L99ASC03TR 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 specializing in automotive, industrial, and power management ICs, with broad portfolio coverage from microcontrollers to analog front-ends and smart power devices.
The L99ASC03TR belongs to ST's ASC (Automotive Smart Controller) family - engineered specifically for sensorless BLDC motor control in safety-critical automotive mechatronics, emphasizing functional safety, thermal resilience, and diagnostic completeness.
FAQ
What is the minimum VS supply voltage for full gate drive functionality?
The L99ASC03TR maintains full high-side gate drive capability down to 6 V VS supply thanks to its two-stage charge pump architecture. Below 6 V, the charge pump cannot sustain sufficient gate bias voltage for reliable N-MOSFET turn-on, triggering undervoltage lockout on the gate driver stage. This threshold is verified per Table 18 in the datasheet (DocID023504 Rev 7, p.37).
How does the BEMF detection module operate without position sensors?
The BEMF module samples motor phase voltage during PWM off-times using configurable comparators and internal timing logic (BEMFCNT register). It detects zero-crossing events to determine rotor position and triggers commutation via SPI-controlled gate sequencing - eliminating Hall-effect or encoder sensors while supporting speeds from 200 RPM upward.
Can the L99ASC03TR be used in systems without an external microcontroller?
No - the L99ASC03TR is a pre-driver requiring an external MCU for high-level motor control algorithms, SPI command generation, and interpretation of diagnostic data (e.g., AOUT multiplexed signals, status registers). It lacks embedded firmware or autonomous commutation logic, functioning strictly as a configurable peripheral.
What thermal protection mechanisms are implemented beyond junction shutdown?
In addition to TSD1/TSD2 junction shutdown, the L99ASC03TR features two programmable thermal warning levels (TW1 = 145 °C, TW2 = 160 °C) that assert flags in SPI status registers and can trigger MCU-initiated derating. These warnings allow proactive speed reduction or torque limiting before reaching critical temperatures - extending reliability in sustained high-load operation.
L99ASC03TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 48-TQFP Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Motor Type - Stepper:
- -
- Motor Type - AC, DC:
- Brushless DC (BLDC)
- Function:
- Controller - Commutation, Direction Management
- Output Configuration:
- Pre-Driver - Half Bridge (3)
- Interface:
- SPI
- Technology:
- -
- Step Resolution:
- -
- Applications:
- -
- Current - Output:
- -
- Voltage - Supply:
- 6V ~ 28V
- Voltage - Load:
- -
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 48-TQFP-EP (7x7)
L99ASC03TR FAQ
1.How can I place an order for L99ASC03TR through Aetrix?
Please submit a Request for Quotation (RFQ) for L99ASC03TR 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 L99ASC03TR reliable?
The price and inventory of L99ASC03TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L99ASC03TR is usually 5 days.
3.What payment methods are accepted for L99ASC03TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L99ASC03TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L99ASC03TR?
L99ASC03TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L99ASC03TR 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 L99ASC03TR?
For technical support, including L99ASC03TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L99ASC03TR requirements.
6.How does Aetrix verify that L99ASC03TR is sourced from the original manufacturer or authorized distributors?
All L99ASC03TR 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 L99ASC03TR meets industry standards.
7.What is the process for return or replacement of L99ASC03TR?
All L99ASC03TR units undergo pre-shipment inspection (PSI). If there is an issue with L99ASC03TR, 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 L99ASC03TR part is unused and in its original packaging.
Return procedure for L99ASC03TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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