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STMicroelectronics LD39100PU33R
- Part No.:
- LD39100PU33R
- Manufacturer:
- STMicroelectronics
- Package:
- 6-VDFN Exposed Pad
- Datasheet:
-
LD39100PU33R.pdf
- Description:
- IC REG LINEAR 3.3V 1A 6DFN
- Quantity:
- Payment:
- Shipping:
Inventory:9,300
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Product details
Overview
LD39100PU33R from STMicroelectronics is an AEC-Q100 qualified, fixed-output 3.3 V ultra-low-dropout linear regulator in DFN6 (3×3 mm) package, delivering 1 A output current with 200 mV typical dropout at full load, 20 µA quiescent current at no load, and ±2.0% output voltage tolerance at 25 °C - designed for automotive post-regulation and low-power battery-powered systems.
For engineers reviewing the LD39100PU33R datasheet, LD39100PU33R pinout, LD39100PU33R application, or LD39100PU33R equivalent, key selection criteria include dropout performance under 1 A load, thermal shutdown behavior at 160 °C, Power Good threshold accuracy (0.92×VOUT), and stability with 1 µF ceramic output capacitor without bypass.
Technical Context
The LD39100PU33R implements a PMOS pass transistor architecture enabling ultra-low dropout (200 mV typ. at 1 A) across its 1.5–5.5 V input range. Its bandgap reference and error amplifier maintain tight output regulation (±2.0% at 25 °C) while supporting logic-controlled enable and open-drain Power Good signaling.
Internal protection includes constant-current short-circuit limiting (2.5 A typ.), thermal shutdown with 20 °C hysteresis, and 70 dB PSRR at 1 kHz. It operates over –40 °C to +125 °C junction temperature and remains stable with 1 µF X5R/X7R ceramic output capacitors (ESR 0–150 mΩ).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3 V ±2.0% at 25 °C - ensures compatibility with 3.3 V logic rails and avoids external resistor divider design effort. |
| Max Output Current | 1 A guaranteed - supports high-current microcontrollers, FPGAs, and interface ICs in compact automotive and consumer modules. |
| Dropout Voltage | 200 mV typ. at 1 A load - enables operation from single-cell Li-ion (3.0 V min.) or 3.3 V supply rails with margin. |
| Quiescent Current | 20 µA typ. at no load - extends battery life in always-on automotive sensors and portable devices. |
| Noise Performance | 85 µVRMS (10 Hz–100 kHz, VOUT = 3.3 V) - suitable for noise-sensitive analog circuits like ADC references and RF power amplifiers. |
| PSRR | 65 dB at 1 kHz, 62 dB at 10 kHz - suppresses ripple from noisy DC-DC pre-regulators in multi-rail power systems. |
| Enable Threshold | VEN(H) = 0.9 V min., VEN(L) = 0.4 V max. - compatible with 1.8 V/3.3 V GPIO control without level-shifting. |
| Power Good Threshold | Rising edge at 0.92×VOUT, falling edge at 0.80×VOUT - provides reliable system power sequencing and fault detection. |
Pinout & Package
LD39100PU33R uses the DFN6 (3×3 mm) wettable flank package with exposed thermal pad (must be connected to GND). The fixed-output version has 6 pins: EN (enable), GND, PG (Power Good), VIN, NC (no connect), and VOUT.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - EN | Logic enable input | Active-high control: >0.9 V = ON, <0.4 V = shutdown (<1 µA IQ); no internal pull-up - requires external bias if not driven. |
| 2 - GND | Analog/digital ground | Common return for all internal circuitry; exposed pad must be soldered to PCB GND plane for thermal and electrical integrity. |
| 3 - PG | Open-drain Power Good flag | High-impedance when VOUT ≥ 0.92×3.3 V; pulled low when VOUT ≤ 0.80×3.3 V - requires external 100 kΩ–1 MΩ pull-up to VIN or VOUT. |
| 4 - VOUT | Regulated 3.3 V output | Delivers up to 1 A; stable with ≥1 µF ceramic capacitor; low-noise output usable for precision analog subsystems. |
| 5 - NC | No-connect terminal | Internally unconnected; must be left floating or tied to GND per layout best practice - no electrical function. |
| 6 - VIN | Input voltage supply | Accepts 1.5–5.5 V DC; requires ≥1 µF low-ESR ceramic capacitor placed adjacent to pin for transient response and stability. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q100 Grade 1 qualification | Validated for automotive applications with operating junction temperature up to +125 °C and robust ESD (4 kV HBM). |
| Ultra-low-noise operation | 85 µVRMS output noise (10 Hz–100 kHz) without bypass capacitor - eliminates need for secondary filtering in sensitive analog signal chains. |
| Thermal and short-circuit protection | Auto-recovery thermal shutdown at 160 °C with 20 °C hysteresis; constant-current limit of 2.5 A prevents damage during output faults. |
| Stable with minimal output capacitance | Guaranteed stability using only 1 µF X5R/X7R ceramic capacitor - reduces BOM count and PCB area vs. traditional LDOs requiring ≥10 µF. |
| Low-quiescent-current shutdown | <1 µA total supply current in OFF mode - critical for always-on vehicle modules meeting ISO 16750-2 quiescent current limits. |
| Wettable flank DFN6 package | Enables automated optical inspection (AOI) of solder joints on bottom-side terminals - improves manufacturing yield in automotive SMT lines. |
Applications
| Automotive Infotainment Power | Industrial Sensor Node Regulator |
|---|---|
|
Use Scenario: Powering audio codecs and display drivers in head-unit systems where EMI-sensitive analog sections coexist with digital processors. IC Role / Device Role / Timing Role: Post-regulator supplying clean 3.3 V to analog front-ends after a noisy buck converter. Use Value: 85 µVRMS noise and 65 dB PSRR at 1 kHz prevent audible artifacts and measurement drift in real-time sensor data acquisition. |
Use Scenario: Providing regulated 3.3 V to low-power wireless sensor transceivers (e.g., BLE, LoRa) in battery-operated condition monitoring nodes. IC Role / Device Role / Timing Role: Primary system regulator enabling long-term operation from coin-cell or energy-harvesting sources. Use Value: 20 µA no-load IQ and <1 µA shutdown current extend operational lifetime beyond 10 years in maintenance-free deployments. |
| Printed Circuit Board Post-Regulation | Game Console Peripheral Interface |
|
Use Scenario: Tight-tolerance 3.3 V supply for FPGA configuration memory and I/O banks on high-density compute boards. IC Role / Device Role / Timing Role: Local point-of-load regulator compensating for IR drop and noise on main 3.3 V distribution rail. Use Value: ±2.0% output accuracy and 0.002 %/mA load regulation ensure reliable FPGA startup and signal integrity across temperature and load variation. |
Use Scenario: Powering USB PHY controllers and touch controller ICs in handheld gaming peripherals subject to mechanical shock and thermal cycling. IC Role / Device Role / Timing Role: Ruggedized 3.3 V source with AEC-Q100 qualification and thermal hysteresis for consumer-grade reliability. Use Value: 125 °C max. junction rating and wettable flank DFN6 package support reflow-compatible assembly and field durability in portable form factors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Torex XC6210B332MR-G | Fixed 3.3 V, 1 A, 250 mV dropout (typ.), 25 µA IQ, no PG pin, SOT-25 package | Lacks Power Good flag and automotive qualification; smaller footprint but higher thermal resistance (RthJA = 200 °C/W) | Choose for cost-sensitive non-automotive applications where PG signaling and thermal performance are not required. |
| ROHM BD39100MUV-LB | Fixed 3.3 V, 1 A, 220 mV dropout (typ.), 30 µA IQ, PG pin, QFN-8 (3×3 mm) with wettable flanks | Same AEC-Q100 Grade 1 rating and PG functionality, but larger 8-pin package increases PCB area and requires different footprint. | Choose when board layout allows QFN-8 and dual-source supply chain diversification is prioritized over package size. |
Compared with XC6210B332MR-G, LD39100PU33R adds automotive qualification and Power Good signaling at the cost of slightly higher quiescent current; versus BD39100MUV-LB, it achieves identical functionality in a smaller 6-pin DFN with superior thermal performance (RthJA = 55 °C/W).
Availability
LD39100PU33R is available at Aetrix Electronics and suitable for automotive infotainment systems, industrial sensor nodes, and game console peripheral interfaces requiring stable component supply with AEC-Q100 compliance and long-lifecycle support.
Supply support for LD39100PU33R 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 certifications including IATF 16949.
LD39100PU33R belongs to ST's high-performance LDO family targeting automotive post-regulation and low-noise portable applications - engineered for ultra-low dropout, sub-µA shutdown, and seamless integration into space-constrained, thermally demanding environments.
FAQ
Is LD39100PU33R pin-compatible with other ST LDOs in DFN6 package?
No - LD39100PU33R uses a unique pinout (EN/GND/PG/VIN/NC/VOUT) distinct from ST's LD3985 or LD3920 families. Pin 5 is NC in this fixed version, whereas adjustable variants use it as ADJ. Layout reuse requires verification against DS6257 Rev 9 Figure 3.
Can LD39100PU33R operate with input voltage below 1.5 V?
No - absolute maximum ratings specify minimum VIN of –0.3 V, but functional operation requires ≥1.5 V per Table 2 and electrical characteristics testing conditions. Below 1.5 V, dropout behavior becomes undefined and output regulation is not guaranteed.
What is the recommended PCB layout for thermal performance?
Connect the exposed thermal pad directly to a solid GND copper pour with ≥4 thermal vias (0.3 mm diameter) to inner/ground layers. Keep VIN and VOUT traces wide and short; place 1 µF input and output ceramic capacitors within 2 mm of respective pins using X5R/X7R dielectrics rated for 6.3 V or higher.
Does the PG pin require a pull-up resistor even if unused?
No - if Power Good functionality is not used, the PG pin must be left floating per Section 6.4 of DS6257. Connecting it to any voltage or GND risks incorrect flag behavior or increased leakage; only add a 100 kΩ–1 MΩ pull-up when actively monitoring the signal.
LD39100PU33R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 6-VDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.4V @ 1A
- Current - Output:
- 1A
- Current - Quiescent (Iq):
- 50 µA
- Current - Supply (Max):
- 300 µA
- PSRR:
- 65dB ~ 62dB (1kHz ~ 10kHz)
- Control Features:
- Enable, Power Good
- Protection Features:
- Over Current, Over Temperature, Short Circuit
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-DFN (3x3)
LD39100PU33R FAQ
1.How can I place an order for LD39100PU33R through Aetrix?
Please submit a Request for Quotation (RFQ) for LD39100PU33R 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 LD39100PU33R reliable?
The price and inventory of LD39100PU33R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LD39100PU33R is usually 5 days.
3.What payment methods are accepted for LD39100PU33R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LD39100PU33R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LD39100PU33R?
LD39100PU33R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LD39100PU33R 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 LD39100PU33R?
For technical support, including LD39100PU33R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LD39100PU33R requirements.
6.How does Aetrix verify that LD39100PU33R is sourced from the original manufacturer or authorized distributors?
All LD39100PU33R 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 LD39100PU33R meets industry standards.
7.What is the process for return or replacement of LD39100PU33R?
All LD39100PU33R units undergo pre-shipment inspection (PSI). If there is an issue with LD39100PU33R, 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 LD39100PU33R part is unused and in its original packaging.
Return procedure for LD39100PU33R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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