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STMicroelectronics LDFM50DT-TR
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- Part No.:
- LDFM50DT-TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-252-3, DPAK (2 Leads + Tab), SC-63
- Datasheet:
-
LDFM50DT-TR.pdf
- Description:
- IC REG LINEAR 5V 500MA DPAK
- Quantity:
- Payment:
- Shipping:
Inventory:1,561
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Product details
Overview
LDFM50DT-TR from STMicroelectronics is a 500 mA very low dropout linear regulator optimized for precision low-voltage power delivery in space-constrained applications. It operates from 2.5 V to 16 V input, delivers up to 12 V fixed or 0.8 V adjustable output with ±1% accuracy at 25 °C, and features 300 mV max dropout at 500 mA - enabling stable regulation near battery end-of-life in portable equipment.
For engineers reviewing the LDFM50DT-TR datasheet, LDFM50DT-TR pinout, LDFM50DT-TR application, or LDFM50DT-TR equivalent, key selection criteria include its logic-controlled enable (EN), open-drain Power Good (PG) output, thermal/current protection, fast load transient response (<5 µs), and DFN6-2x2 package compatibility with high-density PCB layouts.
Technical Context
The LDFM50DT-TR implements a PMOS pass transistor architecture with internal error amplifier, reference voltage generator (0.8 V for adjustable versions), and precision bandgap circuitry - delivering tight line/load regulation (0.01 %/V and 0.1 %/A typ.) across -40 °C to 125 °C junction temperature. Its PG output asserts high when VOUT reaches 92% of nominal and deasserts at 80%, supporting reliable power sequencing.
Designed for low-noise, low-quiescent-current operation, it achieves 45 µVRMS output noise (10 Hz–100 kHz) and 200 µA typical quiescent current at 500 mA load. The EN pin accepts TTL/CMOS-compatible logic thresholds (0.8 V low / 2 V high), and shutdown current remains ≤120 µA over full temperature range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current | 500 mA guaranteed - supports microprocessor core rails and memory I/O without external boost. |
| Dropout voltage | ≤300 mV at 500 mA - enables 3.3 V output from 3.6 V Li-ion battery down to ~3.4 V under full load. |
| Output accuracy | ±1% at 25 °C, ±1.5% over -40 °C to 125 °C - meets tight tolerance requirements for FPGA I/O banks and ADC references. |
| Quiescent current | 200 µA typ. at 500 mA load - minimizes standby power loss in always-on battery systems. |
| Power Good threshold | Rising edge at 0.92×VOUT, falling edge at 0.8×VOUT - provides robust margin for downstream supply sequencing and fault detection. |
| Thermal shutdown | 170 °C with 10 °C hysteresis - protects against sustained overload or poor heatsinking in sealed enclosures. |
| Supply rejection | 60 dB at 120 Hz, 52 dB at 10 kHz (VOUT = 5 V) - suppresses ripple from switching pre-regulators in hybrid power architectures. |
Pinout & Package
Package: DFN6-2x2 mm, 0.65 mm pitch, exposed thermal pad (GND-connected). RoHS-compliant ECOPACK2.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VOUT | Regulated output - connects directly to load; requires 2.2 µF ceramic capacitor with ESR <1 Ω for stability. |
| 2 | ADJ/NC | Adjust pin (not connected on fixed-output variants like LDFM50DT-TR) - left unconnected; no pull-up/down required. |
| 3 | PG | Open-drain Power Good - sinks 6 mA; requires external 10–100 kΩ pull-up to monitor output validity and sequence downstream rails. |
| 4 | GND | Analog/digital ground - tied to exposed thermal pad; must be low-impedance plane for noise control and thermal dissipation. |
| 5 | EN | Enable logic input - active-high (≥2 V); pulling low disables regulator and reduces IQ to ≤120 µA; must not float. |
| 6 | VIN | Input supply - accepts 2.5–16 V; requires 1 µF ceramic capacitor placed ≤12.7 mm from pin with clean analog ground return. |
Key Features
| Feature | Design Value |
|---|---|
| Very low dropout | 300 mV max at 500 mA ensures usable headroom with aging batteries or low-input supplies. |
| Logic-controlled shutdown | EN pin enables system-level power gating with <120 µA shutdown current - critical for IoT endpoint sleep modes. |
| Power Good monitoring | PG output provides deterministic, temperature-stable flag for FPGA configuration, MCU reset assertion, or BMS validation. |
| Fast dynamic response | Load transients (1→500 mA) settle within 10 µs - maintains voltage integrity during CPU burst activity. |
| Integrated protection | Current limiting + thermal shutdown prevent damage during short-circuit or ambient overheating - eliminates need for external fuses. |
Applications
| Medical Portable Ultrasound | Industrial PLC I/O Module |
|---|---|
|
Use Scenario: Powering 1.2 V FPGA fabric and 3.3 V ADC front-end in handheld ultrasound probe with single-cell Li-ion battery. IC Role / Device Role / Timing Role: Primary low-noise LDO delivering regulated rails; PG signals FPGA configuration readiness; EN synchronizes with probe activation. Use Value: 45 µVRMS noise prevents signal corruption in analog receive path; 300 mV dropout extends usable battery runtime by >18% vs legacy LDOs. |
Use Scenario: Providing isolated 5 V and 3.3 V rails for digital I/O isolators and CAN transceivers in DIN-rail mounted PLC module. IC Role / Device Role / Timing Role: Secondary LDO post-regulator after wide-input DC-DC; PG coordinates safe startup of isolated communication interfaces. Use Value: ±1.5% accuracy over -40 °C to 125 °C ensures reliable logic levels across industrial temperature range; thermal shutdown prevents field failure in enclosed cabinets. |
| Edge AI Sensor Node | Thin Client Laptop Subsystem |
|
Use Scenario: Supplying 0.85 V core voltage to ultra-low-power microcontroller (e.g., STM32U5) in battery-operated vibration sensor node. IC Role / Device Role / Timing Role: Core rail LDO with EN controlled by motion-detection interrupt; PG confirms stable VDD before sensor sampling. Use Value: 200 µA quiescent current enables multi-year battery life in duty-cycled operation; fast load response prevents brownout during RF transmit bursts. |
Use Scenario: Generating 1.8 V DDR interface rail and 3.3 V USB controller supply in fanless thin client with thermal constraints. IC Role / Device Role / Timing Role: Compact-area LDO replacing larger SO-8 parts; PG enables BIOS-controlled power sequencing during S3/S4 resume. Use Value: DFN6-2x2 footprint saves >60% board area vs SO-8; 65 °C/W RthJA allows 500 mA operation without heatsink at 60 °C ambient. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar low-dropout linear regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TSM11750TR | Higher dropout (450 mV @ 500 mA), lower accuracy (±2%), no PG output | Lacks power sequencing capability; suitable only for non-critical bias rails | Select when cost is primary constraint and PG/accuracy are not required |
| LP5907MFX-3.3/NOPB | Lower IQ (25 µA), but limited 250 mA output; no thermal shutdown | Insufficient current for FPGA cores; requires external thermal protection | Prefer for ultra-low-power sensor bias, not main processor rails |
Compared with TSM11750TR and LP5907MFX-3.3/NOPB, LDFM50DT-TR uniquely combines 500 mA output, ±1% accuracy, integrated PG, and thermal protection in a 2x2 mm DFN - making it the only drop-in solution for thermally demanding, sequenced power domains in portable industrial electronics.
Availability
LDFM50DT-TR is available at Aetrix Electronics and suitable for medical portable ultrasound, industrial PLC I/O modules, edge AI sensor nodes, and thin client laptop subsystems requiring stable component supply with full traceability and long-term lifecycle support.
Supply support for LDFM50DT-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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.
LDFM50DT-TR belongs to ST's high-performance LDO family designed specifically for low-noise, high-accuracy power delivery in battery-powered and thermally constrained embedded systems - emphasizing dropout minimization, precision, and integrated supervision.
FAQ
What is the maximum allowable input voltage for LDFM50DT-TR?
The absolute maximum DC input voltage is 20 V, but the recommended operating range is 2.5 V to 16 V per the datasheet. Exceeding 16 V risks violating the specified electrical characteristics and may trigger thermal shutdown prematurely due to increased power dissipation. Operation above 16 V is not characterized or guaranteed.
Can LDFM50DT-TR be used with ceramic output capacitors?
Yes - it is fully compatible with ceramic output capacitors, provided minimum capacitance (2.2 µF) and ESR limits are met. The datasheet specifies stable operation with ESR as low as 0.01 Ω for 2.2 µF ceramics; Figure 25 confirms stability in the COUT–ESR plane. X5R/X7R dielectrics are recommended for temperature stability.
Is the ADJ pin functional on LDFM50DT-TR?
No - LDFM50DT-TR is a fixed-output variant (5.0 V), so Pin 2 (ADJ/NC) is internally disconnected and must remain unconnected. Connecting it to any potential violates the "NC" designation and may cause undefined behavior or damage. The adjustable version uses part number LDFMPVR or LDFMPUR.
How does the Power Good (PG) pin behave during thermal shutdown?
During thermal shutdown, the PG pin is actively driven low (≤0.4 V at 6 mA sink) regardless of VOUT level - providing a fail-safe indication of regulator fault. This behavior is explicitly defined in Table 4 and confirmed in Section 6.3 of DS9220 Rev 7, ensuring downstream systems can detect thermal events independently of output voltage collapse.
LDFM50DT-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:
- Obsolete
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 16V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.3V @ 500mA
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 800 µA
- Current - Supply (Max):
- -
- PSRR:
- 60dB ~ 52dB (120Hz ~ 100kHz)
- Control Features:
- Enable, Power Good
- Protection Features:
- Over Current, Over Temperature, Under Voltage Lockout (UVLO)
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DPAK
LDFM50DT-TR FAQ
1.How can I place an order for LDFM50DT-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LDFM50DT-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 LDFM50DT-TR reliable?
The price and inventory of LDFM50DT-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDFM50DT-TR is usually 5 days.
3.What payment methods are accepted for LDFM50DT-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDFM50DT-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LDFM50DT-TR?
LDFM50DT-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LDFM50DT-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 LDFM50DT-TR?
For technical support, including LDFM50DT-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDFM50DT-TR requirements.
6.How does Aetrix verify that LDFM50DT-TR is sourced from the original manufacturer or authorized distributors?
All LDFM50DT-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 LDFM50DT-TR meets industry standards.
7.What is the process for return or replacement of LDFM50DT-TR?
All LDFM50DT-TR units undergo pre-shipment inspection (PSI). If there is an issue with LDFM50DT-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 LDFM50DT-TR part is unused and in its original packaging.
Return procedure for LDFM50DT-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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