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STMicroelectronics L4949EDTR-E
- Part No.:
- L4949EDTR-E
- Manufacturer:
- STMicroelectronics
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
L4949EDTR-E.pdf
- Description:
- IC REG LINEAR 5V 100MA 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,252
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Product details
Overview
L4949EDTR-E from STMicroelectronics is an AEC-Q100-qualified automotive 5 V very low-dropout linear voltage regulator with integrated power-on reset, input voltage sense comparator, and preregulator output (VZ). It delivers up to 100 mA output current with dropout voltage < 0.5 V at 100 mA, quiescent current ≤ 300 µA, and standby output accuracy of 5 V ±1% - designed for microcontroller power supply in engine control units (ECUs) and body control modules (BCMs).
For engineers reviewing the L4949EDTR-E datasheet, L4949EDTR-E pinout, L4949EDTR-E application, or L4949EDTR-E equivalent, key selection criteria include its 40 V transient tolerance, programmable reset delay via external capacitor, sense comparator with 1.23 V threshold, and SO-8 TP package compatibility with automotive thermal and layout constraints.
Technical Context
The device integrates a PNP-based low-dropout regulator core with foldback current limiting, enabling stable 5 V output down to 3 V input while surviving 40 V/1 s transients. Its internal architecture includes a dedicated sense comparator referenced to 1.23 V, independent of output regulation, allowing flexible input voltage supervision via external divider.
The reset circuit uses an internal 4.5 V threshold with 50–200 mV hysteresis and generates a delay-tunable active-low pulse (55–180 ms with 100 nF CT), while the VZ pin provides a stabilized 5 V internal supply (≤10 µA drive) to improve transient immunity below 8 V input - not intended as a user output.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 5 V ±1% (4.95–5.05 V at 25 °C, 1 mA load); maintains regulation across 6–28 V input and 40 V/1 s transients. |
| Dropout Voltage | < 0.5 V at 100 mA; enables operation down to 3 V input without dropout, critical for cold-crank automotive conditions. |
| Quiescent Current | ≤ 300 µA at TJ < 100 °C, IO = 0.3 mA; ensures ultra-low standby power for always-on ECU subsystems. |
| Reset Threshold | 4.5 V with 50–200 mV hysteresis; triggers active-low RES signal when VOUT falls below threshold, preventing MCU brownout. |
| Sense Comparator Ref | 1.23 V typical threshold with 20–200 mV hysteresis; supports configurable undervoltage warning on VS via external resistor divider. |
| Transient Tolerance | 40 V for ≤1 s; withstands load-dump events per ISO 7637-2 without latch-up or functional interruption. |
| Thermal Shutdown | Activates at TJ = 165 °C; protects against sustained overload or poor PCB heatsinking in confined automotive enclosures. |
Pinout & Package
Package: SO-8 TP (Thin Profile), 8-pin surface-mount, ECOPACK® compliant, RoHS and lead-free. Thermal resistance: Rth j-amb = 200 °C/W (max), suitable for natural convection in automotive under-hood environments.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VS) | Input supply voltage | Main DC input (5–28 V); must be decoupled to GND with ≥1 µF capacitor for stability and transient suppression. |
| 2 (SI) | Sense input | Connects to voltage divider from VS to GND; monitors input for low-voltage warnings independent of regulator output. |
| 3 (VZ) | Preregulator output | Stabilized ~5 V internal supply (≤10 µA); optional noise-reduction capacitor (100 nF–1 µF to GND) improves transient immunity below 8 V. |
| 4 (CT) | Reset delay timing | Connect external capacitor (e.g., 100 nF) to GND to set reset pulse delay (55–180 ms); defines noise immunity window. |
| 5–7, 14–17 (GND) | Ground reference | Multiple GND pins reduce impedance; must be connected to common system ground plane with low-inductance routing. |
| 6 (RES) | Reset output | Active-low open-drain output; pulls down when VOUT < 4.5 V; requires external pull-up to MCU VDD for logic-level compatibility. |
| 7 (SO) | Sense output | Open-collector output; pulled low when SI voltage drops below 1.23 V; requires external pull-up for MCU interrupt signaling. |
| 8 (VOUT) | Regulated output | 5 V regulated output (up to 100 mA); requires ≥4.7 µF output capacitor (ESR < 10 Ω @ 10 kHz) for stability. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 qualification | Qualified for automotive Grade 1 (-40 °C to +125 °C ambient), ensuring reliability in engine bay and chassis applications. |
| Integrated reset generator | Programmable delay (via CT pin) and precise 4.5 V threshold enable deterministic MCU reset timing during battery sag or ignition cycles. |
| Dual-supervision capability | Independent VOUT monitoring (RES) and VS monitoring (SO) allow simultaneous brownout detection and pre-failure warning in safety-critical systems. |
| Ultra-low quiescent current | ≤300 µA in standby enables >10-year battery life in always-on telematics or alarm modules powered from vehicle battery. |
| 40 V transient tolerance | Withstands ISO 7637-2 Pulse 5a (load dump) without external TVS, reducing BOM count and board space in ECU designs. |
Applications
| Engine Control Unit (ECU) | Body Control Module (BCM) |
|---|---|
|
Use Scenario: Powering 32-bit MCU, CAN transceiver, and sensor interface ICs during cold-crank (6.5 V battery) and load-dump (40 V surge) events. IC Role / Device Role / Timing Role: Primary 5 V LDO regulator with integrated reset and input supervision; provides clean, sequenced power with deterministic reset assertion. Use Value: Eliminates need for discrete reset IC and voltage supervisor, reducing component count by two while maintaining ASIL-B compliance through dual-monitoring paths. |
Use Scenario: Supplying door module MCU and LIN transceiver in battery-backed memory retention mode with <100 µA total system sleep current. IC Role / Device Role / Timing Role: Low-quiescent-current 5 V regulator with programmable reset delay; enables graceful shutdown and wake-up sequencing. Use Value: Quiescent current ≤300 µA extends vehicle battery life during extended parking; CT-programmed reset prevents spurious wake-ups from electrical noise. |
| Advanced Driver Assistance System (ADAS) Camera ECU | Infotainment Head Unit Power Sequencing |
|
Use Scenario: Regulating power to image signal processor (ISP) and serializer in rear-view camera module exposed to under-hood temperature cycling. IC Role / Device Role / Timing Role: High-precision 5 V supply with thermal shutdown and 165 °C junction protection; ensures fail-safe shutdown before silicon damage. Use Value: Dropout <0.5 V at 100 mA allows operation during cranking dips; SO pin provides early warning of battery degradation before VOUT collapse. |
Use Scenario: Generating controlled 5 V rail for audio DSP and display controller with synchronized reset and voltage monitoring. IC Role / Device Role / Timing Role: Dual-function regulator/supervisor providing both main supply and system-level reset coordination across multiple power domains. Use Value: RES and SO outputs feed separate MCU interrupts, enabling differentiated response (e.g., soft reset vs. full power cycle) based on fault origin. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar automotive LDO regulator with reset and sense functions applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TLV70733PDRVR | 3.3 V fixed output, no sense comparator or VZ preregulator; 200 mA output; 1.8–5.5 V input; no AEC-Q100 rating. | Targeted at non-automotive embedded systems requiring lower voltage; lacks dual-supervision and transient robustness. | Select only for cost-sensitive consumer-grade applications where 40 V tolerance and AEC-Q100 are unnecessary. |
| NCP1117ST50T3G | 5 V fixed output, no reset, no sense, no VZ; 1 A output; 4.75–20 V input; industrial temp range only (−40 to +125 °C, not AEC-Q100 qualified). | Used in general-purpose industrial power rails; missing all supervisory features required for MCU safety boot. | Choose only when supervisory functions are implemented externally and automotive qualification is not required. |
Compared with TLV70733PDRVR and NCP1117ST50T3G, the L4949EDTR-E uniquely integrates AEC-Q100 qualification, 40 V transient tolerance, dual independent supervision (RES + SO), and programmable reset delay - making it the sole option for single-chip, ASIL-compliant MCU power management in production automotive ECUs.
Availability
L4949EDTR-E is available at Aetrix Electronics and suitable for engine control units (ECUs), body control modules (BCMs), and advanced driver assistance system (ADAS) camera ECUs requiring stable component supply, automotive-grade reliability, and long-term lifecycle support.
Supply support for L4949EDTR-E 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, specializing in automotive, industrial, and power management ICs with broad manufacturing and quality infrastructure.
The L4949EDTR-E belongs to ST's automotive analog power portfolio, engineered specifically for microcontroller power supply and system supervision in harsh-temperature, high-transient automotive environments.
FAQ
What is the maximum allowable input voltage for continuous operation?
The L4949EDTR-E supports continuous DC input voltage from 5 V to 28 V. It tolerates transient overvoltage up to 40 V for durations ≤1 second, complying with ISO 7637-2 Pulse 5a load-dump requirements. Operation above 28 V beyond 1 s exceeds absolute maximum ratings and may cause permanent damage.
Can the VZ pin be used as a secondary power output?
No. Pin VZ delivers a stabilized ~5 V internal supply with ≤10 µA current capability and is intended solely to improve transient immunity - not for powering external circuitry. Connecting load to VZ risks destabilizing the internal bias network and degrading reset/sense accuracy.
How does the sense comparator (SI/SO) differ from the reset circuit (VOUT/RES)?
The SI/SO path monitors input voltage (VS) via an external divider against a 1.23 V internal reference, enabling early warning of battery sag before VOUT collapses. The RES output monitors VOUT directly against a 4.5 V threshold, triggering hard reset only after regulation failure - providing layered fault detection.
Is external capacitor selection critical for stability?
Yes. The datasheet mandates ≥1 µF at VS and ≥4.7 µF at VOUT, both with ESR < 10 Ω at 10 kHz. Using undersized or high-ESR capacitors causes oscillation, poor transient response, or failure to regulate - especially under load steps or cold-crank conditions.
L4949EDTR-E Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 28V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.5V @ 100mA
- Current - Output:
- 100mA
- Current - Quiescent (Iq):
- 300 µA
- Current - Supply (Max):
- 5 mA
- PSRR:
- -
- Control Features:
- Reset
- Protection Features:
- Over Temperature, Short Circuit
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
L4949EDTR-E FAQ
1.How can I place an order for L4949EDTR-E through Aetrix?
Please submit a Request for Quotation (RFQ) for L4949EDTR-E 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 L4949EDTR-E reliable?
The price and inventory of L4949EDTR-E are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for L4949EDTR-E is usually 5 days.
3.What payment methods are accepted for L4949EDTR-E?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for L4949EDTR-E transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for L4949EDTR-E?
L4949EDTR-E orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your L4949EDTR-E 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 L4949EDTR-E?
For technical support, including L4949EDTR-E datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your L4949EDTR-E requirements.
6.How does Aetrix verify that L4949EDTR-E is sourced from the original manufacturer or authorized distributors?
All L4949EDTR-E 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 L4949EDTR-E meets industry standards.
7.What is the process for return or replacement of L4949EDTR-E?
All L4949EDTR-E units undergo pre-shipment inspection (PSI). If there is an issue with L4949EDTR-E, 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 L4949EDTR-E part is unused and in its original packaging.
Return procedure for L4949EDTR-E:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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