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STMicroelectronics L4940D2T5-TR
- Part No.:
- L4940D2T5-TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
L4940D2T5-TR.pdf
- Description:
- IC REG LINEAR 5V 1.5A D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:3,631
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Product details
Overview
L4940D2T5-TR from STMicroelectronics is a 5 V fixed-output, 1.5 A low-dropout linear voltage regulator in D²PAK package, featuring 450 mV typical dropout at 1 A, ±2% output voltage accuracy over load/line/temperature, and integrated thermal shutdown, short-circuit, and reverse-polarity protection. It enables efficient battery-powered industrial sensors and portable instrumentation where input-to-output headroom is constrained.
For engineers reviewing the L4940D2T5-TR datasheet, L4940D2T5-TR pinout, L4940D2T5-TR application, or L4940D2T5-TR equivalent, key selection criteria include dropout voltage at full load, quiescent current under light load, thermal resistance (RthJA = 62.5 °C/W), and reverse-input voltage tolerance (–15 V).
Technical Context
The L4940D2T5-TR employs a PNP pass transistor architecture with anti-saturation control to achieve low dropout while maintaining stable regulation across 5 mA–1.5 A output current. Its internal current limiting and safe-area protection prevent device failure during overload or transient conditions.
It delivers precise 5 V output with ≤25 mV load regulation (5 mA to 1.5 A) and 68 dB supply voltage rejection at 120 Hz, making it suitable for post-regulation in switch-mode power supply secondary stages where ripple suppression and tight DC accuracy are required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 5.0 V ±2% (4.9–5.1 V at 500 mA; maintains regulation across 5 mA–1.5 A load) |
| Dropout Voltage | 450 mV typ. at 1 A (enables operation with VI ≥ 5.45 V; supports 6 V battery systems) |
| Quiescent Current | 5–8 mA at 5 mA load; 30–50 mA at 1.5 A (low no-load consumption extends battery life) |
| Thermal Resistance | RthJA = 62.5 °C/W (D²PAK package; requires PCB copper area for >1 W continuous dissipation) |
| Reverse Input Voltage | –15 V (prevents damage from accidental battery reversal in field-deployed equipment) |
| Short-Circuit Current | 2.2–2.9 A (limits fault energy; enables robust protection without external fusing) |
| Supply Rejection | 68 dB at 120 Hz (attenuates SMPS ripple on upstream rails before final regulation) |
Pinout & Package
D²PAK (TO-263) surface-mount package with exposed thermal pad; 3-pin configuration optimized for high-current thermal performance on standard PCBs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (Input) | VIN | Unregulated positive supply input; rated up to +30 V forward, –15 V reverse |
| 2 (Ground) | GND | Reference node for output and internal circuitry; connects to thermal pad for heat sinking |
| 3 (Output) | VOUT | Stable 5 V regulated output; capable of sourcing up to 1.5 A continuously |
Key Features
| Feature | Design Value |
|---|---|
| Precision 5 V output | ±2% tolerance over full operating range ensures compatibility with 5 V logic and analog subsystems without external trimming |
| Low dropout voltage | 450 mV typ. at 1 A allows use in 6 V battery systems with >1 V headroom margin at full load |
| Integrated protection | Thermal shutdown, short-circuit current limiting, and reverse-polarity protection eliminate need for discrete protection components |
| Low quiescent current | 5–8 mA at light load reduces standby power loss in always-on sensor nodes and IoT edge devices |
Applications
| Industrial Sensor Node | Portable Medical Monitor |
|---|---|
Use Scenario: Battery-powered temperature/humidity sensor with microcontroller, ADC, and BLE radio operating from single 6 V alkaline or LiFePO4 cell. IC Role / Device Role / Timing Role: Primary 5 V post-regulator supplying MCU core, analog front-end, and wireless transceiver. Use Value: 450 mV dropout enables >200 hours runtime from 6 V battery at 10 mA avg. load; reverse polarity tolerance prevents field damage during battery replacement. | Use Scenario: Handheld ECG device using rechargeable Li-ion battery (3.0–4.2 V) with boost converter feeding L4940D2T5-TR for clean 5 V rail. IC Role / Device Role / Timing Role: Low-noise, high-PSRR linear regulator for analog signal chain (op-amps, reference, ADC) and digital logic. Use Value: 68 dB supply rejection suppresses boost converter ripple; ±2% output accuracy ensures consistent ADC reference scaling across battery discharge cycle. |
| Automotive Body Control Module | Point-of-Load Power for FPGA I/O |
Use Scenario: Under-hood BCM requiring 5 V supply tolerant to load dump (up to +40 V transient) and reverse battery connection (–15 V). IC Role / Device Role / Timing Role: Secondary regulator downstream of automotive-grade DC/DC converter, providing protected 5 V for microcontroller peripherals. Use Value: –15 V reverse input rating eliminates need for external series diode; thermal shutdown prevents latch-up during sustained overtemperature events. | Use Scenario: FPGA development board with configurable I/O banks requiring tightly regulated 5 V from intermediate 12 V rail. IC Role / Device Role / Timing Role: Point-of-load LDO delivering low-noise 5 V to FPGA I/O bank with fast transient response. Use Value: 25 mV load regulation ensures stable I/O voltage during FPGA configuration bursts; D²PAK thermal performance sustains 1.2 W dissipation without heatsink. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV1117-50CDR | Lower max current (800 mA), higher dropout (1.2 V typ. at 800 mA), RthJA = 70 °C/W (SO-8) | Suitable only for sub-1 A loads; less thermally robust in D²PAK footprint | Select if cost sensitivity outweighs current/headroom requirements and SO-8 is preferred |
| MCP1703T-5002E/MB | Higher accuracy (±0.5%), lower quiescent current (2 µA), but max current limited to 250 mA | Optimized for ultra-low-power always-on circuits, not 1.5 A industrial loads | Choose only for battery-backed RTC or memory backup-not main system regulation |
Compared with TLV1117-50CDR and MCP1703T-5002E/MB, the L4940D2T5-TR uniquely balances 1.5 A output, 450 mV dropout, and –15 V reverse-input tolerance-making it irreplaceable in high-current, battery-reversal-prone industrial and automotive applications.
Availability
L4940D2T5-TR is available at Aetrix Electronics and suitable for industrial sensor nodes, portable medical monitors, automotive body control modules, and FPGA point-of-load power requiring stable component supply with guaranteed long-term manufacturability.
Supply support for L4940D2T5-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 L4940 series belongs to ST's legacy linear regulator product line, engineered specifically for high-reliability, low-dropout post-regulation in battery-powered and harsh-environment systems where protection and precision outweigh switching efficiency.
FAQ
What is the maximum allowable input voltage for continuous operation?
The L4940D2T5-TR supports continuous forward input voltage up to +17 V when output current is 5 mA, per electrical characteristics table. Absolute maximum rating is +30 V, but operation above 17 V risks thermal overload or reduced reliability unless derated per thermal data and ambient conditions.
Does this regulator require an input bypass capacitor?
Yes-ST specifies 0.1 µF ceramic capacitor at the input (CI) for stability and transient response, as shown in all test circuits. Omitting it may cause oscillation or degraded line regulation, especially with long input traces or high-impedance sources.
Can the L4940D2T5-TR be used without a heatsink in free air?
At 1.5 A output and 5 V drop (7.5 W dissipation), junction temperature will exceed 150 °C even with RthJA = 62.5 °C/W. For reliable operation above ~300 mA continuous load, a minimum 25 cm² copper pour (2 oz) is required; heatsinking is mandatory above 600 mA in enclosed environments.
Is the D²PAK package lead-free and RoHS-compliant?
Yes-the L4940D2T5-TR uses ST's ECOPACK®-compliant D²PAK package, meeting RoHS Directive 2011/65/EU and REACH SVHC requirements. The "TR" suffix denotes tape-and-reel packaging compatible with automated SMT assembly.
L4940D2T5-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 17V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.9V @ 1.5A
- Current - Output:
- 1.5A
- Current - Quiescent (Iq):
- 8 mA
- Current - Supply (Max):
- 50 mA
- PSRR:
- 68dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Temperature, Reverse Polarity, Short Circuit
- Operating Temperature:
- -40°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK
L4940D2T5-TR FAQ
1.How can I place an order for L4940D2T5-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for L4940D2T5-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 L4940D2T5-TR reliable?
The price and inventory of L4940D2T5-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L4940D2T5-TR is usually 5 days.
3.What payment methods are accepted for L4940D2T5-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L4940D2T5-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L4940D2T5-TR?
L4940D2T5-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L4940D2T5-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 L4940D2T5-TR?
For technical support, including L4940D2T5-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L4940D2T5-TR requirements.
6.How does Aetrix verify that L4940D2T5-TR is sourced from the original manufacturer or authorized distributors?
All L4940D2T5-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 L4940D2T5-TR meets industry standards.
7.What is the process for return or replacement of L4940D2T5-TR?
All L4940D2T5-TR units undergo pre-shipment inspection (PSI). If there is an issue with L4940D2T5-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 L4940D2T5-TR part is unused and in its original packaging.
Return procedure for L4940D2T5-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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