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STMicroelectronics LDFM50PT-TR
- Part No.:
- LDFM50PT-TR
- Manufacturer:
- STMicroelectronics
- Package:
- TO-252-5, DPAK (4 Leads + Tab), TO-252AD
- Datasheet:
-
LDFM50PT-TR.pdf
- Description:
- IC REG LINEAR 5V 500MA PPAK
- Quantity:
- Payment:
- Shipping:
Inventory:4,613
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Product details
Overview
LDFM50PT-TR from STMicroelectronics is a 500 mA very low dropout linear regulator in DFN6-3x3 package, supporting fixed or adjustable output (0.8 V–12 V), with 1% output accuracy, 300 mV max dropout at 500 mA, and integrated Power Good and enable logic control - designed for powering low-voltage microprocessors and memory in space-constrained portable and industrial systems.
For engineers reviewing the LDFM50PT-TR datasheet, LDFM50PT-TR pinout, LDFM50PT-TR application, or LDFM50PT-TR equivalent, key selection criteria include dropout voltage under full load, quiescent current across temperature, PG threshold accuracy, thermal shutdown behavior, and stability with ceramic output capacitors.
Technical Context
The LDFM50PT-TR employs a high-gain error amplifier with internal reference (0.8 V for adjustable versions) and PMOS pass transistor architecture to achieve ultra-low dropout and fast transient response. Its open-drain Power Good output asserts when VOUT reaches 92% of nominal and deasserts at 80%, enabling precise power sequencing.
It integrates thermal shutdown (170 °C, 10 °C hysteresis) and current limiting (~0.8 A), operates from −40 °C to +125 °C junction temperature, and maintains stability with ≥2.2 µF ceramic output capacitance and specified ESR range - confirmed per Figures 24–25 in DS9220 Rev 7.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output current | 500 mA guaranteed continuous - supports core rails for Cortex-M7 microcontrollers and LPDDR3 memory I/O. |
| Dropout voltage | ≤300 mV at 500 mA load - enables regulation from 3.6 V input to 3.3 V output with margin at high temperature. |
| Output accuracy | ±1% at 10 mA, ±1.5% over full load/temperature - meets tight tolerance requirements for FPGA auxiliary supplies. |
| Quiescent current | 200 µA typical at 500 mA load - minimizes battery drain in always-on sensor nodes. |
| Power Good threshold | Rising edge at 0.92×VOUT, falling edge at 0.8×VOUT - provides clean reset signaling for SoC boot sequencing. |
| PSRR | 60 dB at 120 Hz, 52 dB at 10 kHz (VOUT = 5 V) - suppresses ripple from noisy DC-DC pre-regulators. |
| Noise density | 45 µVRMS (10 Hz–100 kHz, 100 mA load) - suitable for analog sensor signal chains without additional LDO filtering. |
Pinout & Package
Package: DFN6-3x3 mm, 0.4 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 placed adjacent to pin. |
| 2 | ADJ/NC | Feedback input for adjustable versions; not connected (NC) in fixed-output variants like LDFM50PT-TR. |
| 3 | PG | Open-drain Power Good - requires external pull-up (10–100 kΩ) to monitor output validity during startup/fault. |
| 4 | GND | Analog/digital ground - tied to exposed thermal pad; must be low-impedance plane for thermal and noise performance. |
| 5 | EN | Active-high enable - logic low (<0.8 V) disables regulator and reduces IQ to ≤120 µA; no internal pull-up/down. |
| 6 | VIN | Input supply (2.5–16 V) - requires ≥1 µF ceramic capacitor within 12.7 mm of pin to suppress high-frequency noise. |
Key Features
| Feature | Design Value |
|---|---|
| Logic-controlled shutdown | EN pin reduces quiescent current to ≤120 µA over full temperature range - enables zero-power standby in battery systems. |
| Fast dynamic response | Load transient recovery <50 µs (1→500 mA step, COUT = 2.2 µF) - prevents brownout during CPU burst activity. |
| Internal protection | Thermal shutdown (170 °C) + foldback current limit (~0.8 A) - eliminates need for external fault-handling circuitry. |
| Low-noise operation | 45 µVRMS output noise with 2.2 µF X7R ceramic output cap - avoids dedicated noise-filtering LDO stages in RF subsystems. |
| Wide output flexibility | Fixed 5.0 V version (LDFM50PT-TR); adjustable variant supports 0.8–12 V via external resistor divider - simplifies BOM across product variants. |
Applications
| Industrial PLC I/O Module | Portable Medical Monitor |
|---|---|
|
Use Scenario: Powering isolated analog front-end (AFE) and microcontroller in DIN-rail mounted programmable logic controller. IC Role / Device Role / Timing Role: Primary 5.0 V rail regulator delivering stable, low-noise supply to precision ADCs and ARM Cortex-M4 core. Use Value: 300 mV dropout allows operation from 5.5 V DC bus even at elevated ambient temperatures; PG signal validates rail before enabling isolation gate drivers. |
Use Scenario: Battery-backed power management in handheld ECG device with real-time display and Bluetooth LE connectivity. IC Role / Device Role / Timing Role: Main system LDO supplying 5.0 V to MCU, OLED driver, and analog sensor interface. Use Value: 200 µA quiescent current extends 2000 mAh Li-ion battery life to >72 hours in sleep mode; EN pin enables rapid wake/sleep cycling. |
| Laptop USB-C Docking Station | Automotive Infotainment Display |
|
Use Scenario: Regulating 5.0 V USB PD sink power for downstream peripherals (HDMI, Ethernet, USB hubs). IC Role / Device Role / Timing Role: Secondary LDO post-regulator ensuring clean 5.0 V for USB enumeration and hot-plug detection circuits. Use Value: 60 dB PSRR at 120 Hz rejects ripple from upstream buck converter; fast line transient response prevents USB disconnect events. |
Use Scenario: Supplying 5.0 V to touch controller and display timing controller in automotive-grade infotainment head unit. IC Role / Device Role / Timing Role: Safety-critical auxiliary LDO with PG monitoring to confirm rail integrity before display initialization. Use Value: −40 °C to +125 °C operation meets AEC-Q100 Grade 2 requirements; PG threshold hysteresis prevents chatter during cold cranking. |
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 |
|---|---|---|---|
| Texas Instruments TPS7A2050PDBVR | Lower IQ (6.5 µA typ.), but 300 mA max output and 400 mV dropout at 300 mA - less headroom for high-current loads. | Preferred for ultra-low-power IoT sensors; unsuitable for 500 mA sustained loads like display drivers. | Select if battery life dominates over peak current capability; verify thermal derating in DFN1206 package. |
| Analog Devices ADP1740ACPZ-5-R7 | 500 mA rated, 200 mV dropout at 500 mA, but only −40 °C to +105 °C rating and no PG output - lacks automotive thermal margin and sequencing support. | Suitable for commercial-grade embedded controllers; cannot replace LDFM50PT-TR in extended-temperature industrial designs. | Choose where PG signaling is unnecessary and ambient temperature stays below 105 °C; validate PCB thermal relief. |
Compared with TPS7A2050PDBVR and ADP1740ACPZ-5-R7, the LDFM50PT-TR uniquely combines 500 mA output, 125 °C operation, and integrated Power Good in a thermally enhanced DFN6-3x3 package - making it optimal for thermally demanding, safety-aware applications requiring rail validation.
Availability
LDFM50PT-TR is available at Aetrix Electronics and suitable for industrial PLC I/O modules, portable medical monitors, laptop docking stations, and automotive infotainment displays requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LDFM50PT-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, specializing in power management, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.
The LDFM series was developed to address demand for high-precision, low-noise, thermally robust LDOs in compact packages - specifically targeting next-generation portable, medical, and industrial equipment where efficiency, reliability, and board space are critical.
FAQ
What is the minimum output capacitance required for stability with LDFM50PT-TR?
The LDFM50PT-TR requires a minimum 2.2 µF ceramic output capacitor (X5R/X7R) with ESR between 0.01 Ω and 0.5 Ω at 100 kHz, as validated in Figure 25 of DS9220 Rev 7. Using lower capacitance risks oscillation; tantalum or aluminum electrolytics are not recommended due to ESR drift and aging effects.
Does LDFM50PT-TR support adjustable output voltages?
No - LDFM50PT-TR is a fixed 5.0 V output variant. The ADJ pin (Pin 2) is not connected internally. Adjustable versions use part numbers like LDFMPUR (DFN6-3x3) or LDFMPVR (DFN6-2x2), where Pin 2 serves as the feedback node for external resistor dividers setting VOUT from 0.8 V upward.
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 EN state, providing unambiguous fault indication. PG resumes normal operation only after junction temperature falls below 160 °C (170 °C trip minus 10 °C hysteresis) and VOUT stabilizes within tolerance.
Can LDFM50PT-TR be used with input voltage below 2.5 V?
No - the absolute minimum input voltage is 2.5 V per Table 2 (DS9220 Rev 7). Operation below this violates absolute maximum ratings and may cause unpredictable dropout behavior or failure to regulate. For sub-2.5 V inputs, consider ST's STLQ015 series or similar ultra-low-VIN LDOs.
LDFM50PT-TR Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-252-5, DPAK (4 Leads + Tab), TO-252AD
- 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:
- PPAK
LDFM50PT-TR FAQ
1.How can I place an order for LDFM50PT-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for LDFM50PT-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 LDFM50PT-TR reliable?
The price and inventory of LDFM50PT-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDFM50PT-TR is usually 5 days.
3.What payment methods are accepted for LDFM50PT-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDFM50PT-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LDFM50PT-TR?
LDFM50PT-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LDFM50PT-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 LDFM50PT-TR?
For technical support, including LDFM50PT-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDFM50PT-TR requirements.
6.How does Aetrix verify that LDFM50PT-TR is sourced from the original manufacturer or authorized distributors?
All LDFM50PT-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 LDFM50PT-TR meets industry standards.
7.What is the process for return or replacement of LDFM50PT-TR?
All LDFM50PT-TR units undergo pre-shipment inspection (PSI). If there is an issue with LDFM50PT-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 LDFM50PT-TR part is unused and in its original packaging.
Return procedure for LDFM50PT-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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