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STMicroelectronics LF33CDT-TRY
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- Part No.:
- LF33CDT-TRY
- Manufacturer:
- STMicroelectronics
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LF33CDT-TRY.pdf
- Description:
- IC REG LINEAR 3.3V 500MA DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:3,505
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Product details
Overview
LF33CDT-TRY from STMicroelectronics is a 3.3 V, ±2% tolerance, automotive-grade low-dropout linear voltage regulator in DPAK package with 500 mA output current capability, 0.45 V dropout at 200 mA, and logic-controlled shutdown (TTL-compatible enable pin). It operates from −40 °C to 125 °C and is qualified per AEC-Q100 for use as a local power supply in engine control units, ADAS camera modules, and infotainment domain controllers.
For engineers reviewing the LF33CDT-TRY datasheet, LF33CDT-TRY pinout, LF33CDT-TRY application, or LF33CDT-TRY equivalent, key selection considerations include its 50 µA quiescent current in OFF mode, 2.2 µF minimum output capacitance requirement, ±2% output voltage accuracy over temperature, and integrated thermal/current protection for automotive under-hood environments.
Technical Context
The LF33CDT-TRY implements a PNP-based LDO architecture with internal current limiting and thermal shutdown, enabling robust operation in high-temperature automotive zones. Its TTL-compatible enable input (pin 2) allows precise system-level power sequencing and standby mode control without external level-shifting circuitry.
It delivers stable 3.3 V regulation across input voltages from 4.3 V to 16 V, with 80 dB supply voltage rejection at 120 Hz and 50 µV RMS output noise (10 Hz–100 kHz), making it suitable for powering noise-sensitive analog and digital subsystems in safety-critical vehicle electronics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 3.3 V ±2% at 25 °C; maintains regulation across −40 °C to 125 °C junction temperature |
| Dropout Voltage | 0.45 V typical at 200 mA load; enables operation with minimal headroom (e.g., 3.75 V input sustains 3.3 V output) |
| Quiescent Current | 50 µA in OFF mode; reduces standby power in always-on vehicle networks |
| Output Current | 500 mA continuous; supports microcontroller cores, CAN transceivers, and sensor interfaces |
| Input Voltage Range | 4.3 V to 16 V DC; compatible with 12 V automotive battery systems including load-dump transients |
| Stability Capacitor | 2.2 µF ceramic output capacitor (ESR 0.1–10 Ω); minimizes PCB area and BOM cost |
| Supply Rejection | 80 dB at 120 Hz; suppresses alternator ripple and switching noise from adjacent DC/DC converters |
Pinout & Package
DPAK (TO-252-3) package with exposed thermal pad electrically connected to GND; thermally optimized for surface-mount automotive PCBs requiring high reliability under thermal cycling.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 – Input (IN) | Main power input | Accepts 4.3–16 V DC; connects to upstream filtering or DC/DC stage |
| 2 – Enable (EN) | Logic-controlled shutdown input | TTL-compatible; <0.8 V disables regulator (50 µA IQ), >2 V enables (500 µA IQ) |
| 3 – Ground (GND) | Reference and return path | Internally tied to exposed thermal pad; must be solidly connected to PCB ground plane |
| 4 – Output (OUT) | Regulated 3.3 V supply | Delivers up to 500 mA; requires ≥2.2 µF ceramic capacitor to OUT–GND for stability |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualified | Qualified for automotive Grade 1 (−40 °C to 125 °C) with PAT/SYL/SBL statistical testing |
| Low-noise regulation | 50 µV RMS output noise (10 Hz–100 kHz) enables clean power for ADCs and RF receivers |
| Fast enable/disable response | EN pin transitions regulate within microseconds-supports dynamic power gating in ECU sleep/wake cycles |
| Integrated protection | Thermal shutdown and current limiting prevent damage during overload or ambient overheating |
| Minimal external components | Only two capacitors required (0.1 µF input, 2.2 µF output); eliminates need for compensation networks |
Applications
| Engine Control Unit (ECU) Power Rail | ADAS Camera Module Supply |
|---|---|
Use Scenario: Powers 32-bit MCU core, CAN FD transceiver, and analog front-end in gasoline/diesel engine management systems. IC Role / Device Role / Timing Role: Primary 3.3 V local regulator with EN pin synchronized to ECU wake-up interrupt signal. Use Value: 50 µA OFF-mode current extends battery life during vehicle parking; 0.45 V dropout ensures regulation during cold-crank (6.5 V battery). | Use Scenario: Supplies image signal processor and high-speed serializer in 8 MP surround-view camera. IC Role / Device Role / Timing Role: Low-noise 3.3 V source decoupled from noisy 5 V DC/DC converter powering motorized lens actuators. Use Value: 50 µV RMS noise prevents pixel pattern artifacts; AEC-Q100 qualification guarantees field reliability at 125 °C ambient. |
| Infotainment Domain Controller | Body Control Module (BCM) Subsystem |
Use Scenario: Provides clean 3.3 V rail for audio codec, touch controller, and Ethernet PHY in head-unit mainboard. IC Role / Device Role / Timing Role: Secondary regulator downstream of main PMIC; EN pin controlled by application processor GPIO. Use Value: 80 dB SVR at 120 Hz suppresses alternator ripple; ±2% accuracy ensures consistent I²S timing margin across temperature. | Use Scenario: Powers LIN transceiver, EEPROM, and LED driver IC in door module or lighting control unit. IC Role / Device Role / Timing Role: Standby-capable local regulator enabling low-power wake-on-LIN functionality. Use Value: TTL-compatible EN pin integrates directly with LIN bus transceiver's INH output-no level shifter needed. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LDL1133PU33R | Lower IQ (2.5 µA OFF), but only 300 mA output; no AEC-Q100 qualification | Suitable for non-automotive portable devices where ultra-low standby dominates | Select only if AEC-Q100 is not required and load current ≤300 mA |
| TLV73333PDBVR | Higher dropout (0.22 V @ 300 mA), ±1% accuracy, but rated only to 105 °C | Applicable in industrial control panels with lower ambient temperature constraints | Choose when tighter voltage accuracy is critical and junction temperature stays ≤105 °C |
Compared with LDL1133PU33R and TLV73333PDBVR, the LF33CDT-TRY uniquely balances AEC-Q100 compliance, 500 mA drive, and 50 µA OFF-mode current-making it the only drop-in solution for automotive ECU and ADAS sub-systems requiring full temperature range operation and system-level power gating.
Availability
LF33CDT-TRY is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, and infotainment domain controllers requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LF33CDT-TRY 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 microcontrollers, power management ICs, sensors, and automotive-grade analog devices.
The LFXX series is ST's automotive-qualified LDO family targeting local regulation in harsh-temperature vehicle subsystems, emphasizing low dropout, ultra-low quiescent current, and functional safety readiness.
FAQ
What is the maximum allowable input voltage for LF33CDT-TRY?
The absolute maximum DC input voltage is 40 V, but the device enters shutdown above 18 V. For normal regulation, the recommended operating input range is 4.3 V to 16 V-covering cold-crank (6.5 V), nominal (13.5 V), and load-dump (18 V transient) conditions in 12 V automotive systems. Operation above 16 V should be limited to short-duration transients only.
Does LF33CDT-TRY require an input capacitor?
Yes-a 0.1 µF ceramic capacitor placed close to the IN pin is specified in the datasheet to ensure stability and suppress high-frequency noise from upstream sources. This capacitor mitigates ringing during fast load transients and improves PSRR performance above 10 kHz. Omitting it may cause oscillation or degraded transient response under dynamic loads.
How is thermal performance affected by PCB layout?
Thermal resistance (RthJA) drops from 100 °C/W (standard 2-layer board) to ~50 °C/W with a 4 cm² copper pour connected to the exposed thermal pad on a 4-layer board. The DPAK's tab is internally connected to GND, so the pad must be soldered to a large, multi-layer GND plane with ≥6 thermal vias (0.3 mm diameter) to achieve rated 500 mA output at 125 °C ambient.
Can LF33CDT-TRY be used without connecting the EN pin?
No-leaving EN floating risks undefined behavior due to TTL input threshold sensitivity. The datasheet mandates either pulling EN to IN (for always-on operation) or to GND (for permanent disable). For default-enable operation, connect EN directly to IN via a 10 kΩ resistor; for default-disable, tie EN to GND. External pull-up/pull-down resistors must be used-no internal biasing is provided.
LF33CDT-TRY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 16V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 1.3V @ 500mA
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 2 mA
- Current - Supply (Max):
- 12 mA
- PSRR:
- 80dB ~ 65dB (120Hz ~ 65dB)
- Control Features:
- -
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
LF33CDT-TRY FAQ
1.How can I place an order for LF33CDT-TRY through Aetrix?
Please submit a Request for Quotation (RFQ) for LF33CDT-TRY 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 LF33CDT-TRY reliable?
The price and inventory of LF33CDT-TRY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LF33CDT-TRY is usually 5 days.
3.What payment methods are accepted for LF33CDT-TRY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LF33CDT-TRY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LF33CDT-TRY?
LF33CDT-TRY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LF33CDT-TRY 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 LF33CDT-TRY?
For technical support, including LF33CDT-TRY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LF33CDT-TRY requirements.
6.How does Aetrix verify that LF33CDT-TRY is sourced from the original manufacturer or authorized distributors?
All LF33CDT-TRY 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 LF33CDT-TRY meets industry standards.
7.What is the process for return or replacement of LF33CDT-TRY?
All LF33CDT-TRY units undergo pre-shipment inspection (PSI). If there is an issue with LF33CDT-TRY, 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 LF33CDT-TRY part is unused and in its original packaging.
Return procedure for LF33CDT-TRY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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