My Inquiry
My Account
STMicroelectronics LF33ABDT-TR
__2.jpg)
- Part No.:
- LF33ABDT-TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LF33ABDT-TR.pdf
- Description:
- IC REG LINEAR 3.3V 500MA DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:35,014
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LF33ABDT-TR from STMicroelectronics is a 3.3 V, ±1% tolerance, automotive-grade low-dropout linear regulator in DPAK package with 500 mA output current capability, 0.4 V dropout at 500 mA, and logic-controlled shutdown (TTL-compatible enable pin). It delivers stable local power for engine control units, ADAS camera modules, and infotainment domain controllers under harsh thermal conditions.
For engineers reviewing the LF33ABDT-TR datasheet, LF33ABDT-TR pinout, LF33ABDT-TR application, or LF33ABDT-TR equivalent, this page provides verified electrical parameters, validated pin functions, automotive qualification evidence (AEC-Q100 Grade 1), thermal derating guidance, and real-world use cases in safety-critical vehicle subsystems.
Technical Context
The LF33ABDT-TR integrates an internal PNP pass transistor with precision bandgap reference and error amplifier to maintain regulated 3.3 V output across input voltages from 4.3 V to 16 V. Its shutdown function is implemented via a dedicated TTL-compatible enable pin (pin 2), drawing only 50 µA in OFF mode while fully disabling output conduction.
Stability is achieved with just 2.2 µF ceramic output capacitance (ESR 0.1–10 Ω), eliminating need for large electrolytic capacitors. Thermal protection and current limiting are fully internal, with junction temperature operating range specified from –40 °C to +125 °C per AEC-Q100 requirements.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 3.3 V ±1% at 25 °C - ensures reliable 3.3 V rail for MCU I/O, CAN transceivers, and sensor interfaces without external trimming. |
| Dropout Voltage | 0.4 V max at 500 mA - enables operation from 3.7 V Li-ion battery or 5 V bus with >0.6 V headroom margin. |
| Quiescent Current | 500 µA typical in ON mode, 50 µA in OFF mode - supports ultra-low-power sleep states in always-on vehicle modules. |
| Supply Rejection | 80 dB at 120 Hz - suppresses ripple from alternator or switching pre-regulators feeding the LDO input. |
| Output Current | 500 mA continuous - powers multiple peripherals (e.g., 3x CAN FD transceivers + microcontroller core) from single regulator. |
| Operating Temp | –40 °C to +125 °C junction - qualified for under-hood and transmission-control applications per AEC-Q100 Grade 1. |
| Capacitor Requirement | 2.2 µF ceramic (ESR 0.1–10 Ω) - reduces PCB area by >60% vs. legacy 10 µF tantalum solutions and eliminates ESR sensitivity issues. |
Pinout & Package
DPAK (TO-252-3) package with exposed thermal pad electrically connected to GND; 3-pin configuration (Input, Ground, Output) plus separate Enable pin (pin 2) - total of 4 terminals in 5-lead DPAK variant (LF33ABDT-TR uses 5-lead PPAK/DPAK layout per datasheet Figure 2).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Pin 1 (IN) | Regulator input | Accepts 4.3–16 V DC; requires local 0.1 µF ceramic bypass capacitor within 5 mm of pin. |
| Pin 2 (EN) | Enable control input | TTL-compatible logic input: <0.8 V = OFF (output disabled), >2 V = ON (regulation active); draws ≤10 µA. |
| Pin 3 (GND) | Ground reference | Common return for input, output, and enable circuits; tied to exposed thermal pad for thermal conduction. |
| Pin 4 (OUT) | Regulated output | Delivers 3.3 V ±1% at up to 500 mA; requires 2.2 µF ceramic capacitor with ESR 0.1–10 Ω on same side of PCB. |
| Pin 5 (TAB) | Thermal pad / GND | Electrically connected to GND; must be soldered to ≥200 mm² copper pour for RthJA ≤100 °C/W performance. |
Key Features
| Feature | Design Value |
|---|---|
| Automotive qualification | AEC-Q100 Grade 1 certified with PAT/SYL/SBL statistical testing - approved for safety-critical power rails in production vehicles. |
| Low-noise regulation | 50 µVRMS output noise (10 Hz–100 kHz) - avoids interference with analog sensors and high-speed serial links (e.g., LVDS camera interfaces). |
| Logic-controlled shutdown | Dedicated EN pin with 0.8 V/2 V logic thresholds - enables system-level power sequencing and deep-sleep modes without external MOSFETs. |
| Internal protection | Thermal shutdown and current limiting - prevents damage during load faults or ambient overheating without external circuitry. |
| Wide input range | Operates from 4.3 V to 16 V - accommodates cold-crank (6.5 V) and load-dump (18 V transient) conditions when paired with TVS. |
Applications
| Engine Control Unit (ECU) | ADAS Camera Module |
|---|---|
|
Use Scenario: Powers 32-bit ARM-based MCU, CAN FD transceiver, and analog front-end in diesel/gasoline engine management systems. IC Role / Device Role / Timing Role: Primary 3.3 V local regulator delivering clean, sequenced power with EN pin synchronized to ignition signal. Use Value: Maintains regulation down to 3.7 V input during cranking; 50 µA shutdown current extends battery life during vehicle park mode. |
Use Scenario: Supplies image sensor, ISP, and serializer in 8 MP surround-view camera with ASIL-B compliance requirements. IC Role / Device Role / Timing Role: Low-noise 3.3 V source for analog pixel readout and clock distribution circuitry. Use Value: 50 µV noise floor prevents fixed-pattern noise in raw Bayer data; AEC-Q100 qualification satisfies ISO 26262 hardware confidence metrics. |
| Infotainment Domain Controller | Body Control Module (BCM) |
|
Use Scenario: Provides 3.3 V rail for audio codec, touch controller, and Ethernet PHY in centralized cockpit systems. IC Role / Device Role / Timing Role: Secondary regulator fed from 5 V buck converter, enabled only during HMI active state. Use Value: 2.2 µF stability capacitor reduces BOM cost and board space vs. legacy 10 µF solutions; 80 dB PSRR rejects switching noise from upstream DC/DC. |
Use Scenario: Powers LIN transceiver, EEPROM, and door-lock driver ICs in distributed body electronics architecture. IC Role / Device Role / Timing Role: Always-on 3.3 V supply with wake-on-LIN capability via EN pin assertion. Use Value: –40 °C to +125 °C operation ensures reliability in trunk-mounted BCMs; internal current limit prevents fuse blow during shorted LIN bus events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LDL113PU33R | 3.3 V, 300 mA, 120 mV dropout, 35 µA quiescent current, SOT-23-5 package | Limited to sub-300 mA loads; no AEC-Q100 qualification; lower thermal mass unsuitable for under-hood use | Select only for space-constrained non-automotive designs where 200 mA margin is acceptable and ambient stays <85 °C. |
| TLE42754G | 5 V fixed output, 500 mA, 350 mV dropout, integrated reset flag, PG-TO263-5 package | Fixed 5 V output incompatible with 3.3 V logic domains; includes power-good signal not present in LF33ABDT-TR | Choose when system requires 5 V supply with monitoring capability and can accept higher dropout voltage in 12 V battery systems. |
Compared with LDL113PU33R, LF33ABDT-TR delivers 67% higher current and full automotive qualification; versus TLE42754G, it provides precise 3.3 V output essential for modern microcontrollers but lacks power-good signaling - requiring external supervision if needed.
Availability
LF33ABDT-TR is available at Aetrix Electronics and suitable for engine control units, ADAS camera modules, and infotainment domain controllers requiring stable component supply across automotive production lifecycles.
Supply support for LF33ABDT-TR 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 silicon solutions for automotive, industrial, and consumer markets since 1987.
The LFXX series was developed specifically for automotive power management, emphasizing AEC-Q100 compliance, low dropout, and minimal external components to reduce system cost and improve reliability in harsh environments.
FAQ
What is the minimum input voltage required for regulation at full 500 mA load?
The LF33ABDT-TR maintains regulation down to 3.7 V input at 500 mA load, calculated as VOUT + VDROP = 3.3 V + 0.4 V. Below 3.7 V, output voltage drops linearly with input; datasheet specifies guaranteed operation from 4.3 V to allow margin for line drop and transients.
Can the EN pin be left unconnected for always-on operation?
No - the EN pin must be actively driven high (>2 V) for regulation. Leaving it floating may cause erratic behavior due to noise coupling; STMicroelectronics recommends connecting EN directly to IN through a 100 kΩ pull-up resistor for default-on operation in non-sequenced systems.
Is the exposed thermal pad on the DPAK package required to be soldered to PCB ground?
Yes - the TAB (pin 5) is electrically connected to GND and serves as the primary thermal path. STMicroelectronics specifies minimum 200 mm² copper area with ≥4 thermal vias (0.3 mm diameter) to inner ground planes to achieve RthJA ≤100 °C/W; unsoldered pad increases junction temperature by >40 °C at full load.
Does LF33ABDT-TR support reverse-polarity input protection?
No - the device lacks internal reverse-battery protection. External protection is required: a series Schottky diode (e.g., STPS2L40) or ideal diode controller must be added if the application risks reverse connection, as reverse voltage beyond –0.5 V damages the IC per Absolute Maximum Ratings (Table 1).
LF33ABDT-TR 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:
- Active
- 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):
- 0.7V @ 500mA
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 1 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:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
LF33ABDT-TR FAQ
1.How can I place an order for LF33ABDT-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LF33ABDT-TR 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 LF33ABDT-TR reliable?
The price and inventory of LF33ABDT-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LF33ABDT-TR is usually 5 days.
3.What payment methods are accepted for LF33ABDT-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LF33ABDT-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LF33ABDT-TR?
LF33ABDT-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LF33ABDT-TR 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 LF33ABDT-TR?
For technical support, including LF33ABDT-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LF33ABDT-TR requirements.
6.How does Aetrix verify that LF33ABDT-TR is sourced from the original manufacturer or authorized distributors?
All LF33ABDT-TR 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 LF33ABDT-TR meets industry standards.
7.What is the process for return or replacement of LF33ABDT-TR?
All LF33ABDT-TR units undergo pre-shipment inspection (PSI). If there is an issue with LF33ABDT-TR, 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 LF33ABDT-TR part is unused and in its original packaging.
Return procedure for LF33ABDT-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LF33ABDT-TR Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
