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STMicroelectronics LDK715PU42R
- Part No.:
- LDK715PU42R
- Manufacturer:
- STMicroelectronics
- Package:
- 8-VDFN Exposed Pad
- Datasheet:
-
LDK715PU42R.pdf
- Description:
- IC REG LINEAR 4.2V 85MA 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,857
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Product details
Overview
LDK715PU42R from STMicroelectronics is a high-input-voltage, ultra-low-quiescent-current LDO linear regulator delivering 4.2 V at up to 85 mA output current, with 500 mV typical dropout at full load, 5 µA typical quiescent current, and stable operation from 4.3 V to 24 V input across –40 °C to 125 °C. It is used in battery-powered industrial sensors requiring long runtime and wide VIN tolerance.
For engineers reviewing the LDK715PU42R datasheet, LDK715PU42R pinout, LDK715PU42R application, or LDK715PU42R equivalent, key selection criteria include dropout voltage at 85 mA, ceramic capacitor compatibility (0.47–10 µF), thermal resistance (52 °C/W for DFN8), short-circuit protection, and guaranteed output accuracy (±2% over temperature).
Technical Context
The LDK715PU42R implements a bandgap reference-based error amplifier with internal current limiting and thermal shutdown. Its low-dropout architecture uses a PMOS pass transistor, enabling regulation down to 500 mV headroom at 85 mA while maintaining ±2% output accuracy over full temperature and line/load conditions.
It supports fast transient response with 0.7 ms turn-on time and achieves 57 dB supply voltage rejection at 100 kHz. Stability is ensured with ceramic output capacitors as low as 0.47 µF, eliminating need for tantalum or electrolytic types.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output voltage | Fixed 4.2 V ±1% at 25 °C; ±2% over –40 °C to 125 °C - ensures precise biasing for 4.2 V Li-ion charging circuits or MCU I/O rails. |
| Input voltage range | 4.3 V to 24 V DC - enables direct connection to unregulated 12 V/24 V industrial buses or multi-cell battery stacks without pre-regulation. |
| Max output current | 85 mA guaranteed - sufficient to power low-power microcontrollers, RF transceivers, or sensor signal chains without external boost. |
| Dropout voltage | 500 mV typ. at 85 mA - allows >90% efficiency at 5 V output when VIN = 5.5 V, critical for energy-constrained systems. |
| Quiescent current | 5 µA typ. at full load - reduces standby power loss by >95% vs. standard LDOs, extending battery life in always-on IoT nodes. |
| Output noise | 210 µVRMS (200 Hz–100 kHz) - low enough for analog sensor front-ends or ADC reference supplies without added filtering. |
| SVR @ 100 kHz | 57 dB - suppresses high-frequency switching noise from adjacent DC-DC converters, improving signal integrity. |
Pinout & Package
LDK715PU42R is packaged in DFN8 3×3 mm, a thermally enhanced, leadless surface-mount package with exposed thermal pad. It offers 52 °C/W junction-to-ambient thermal resistance, supporting higher continuous output current than SOT23-5L in space-constrained designs.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| IN (Pin 1) | Input voltage supply | Accepts 4.3–24 V DC; requires ≥0.1 µF local bypass capacitor to GND for transient immunity. |
| NC (Pins 2, 3, 5, 6, 7) | No connect | Internally floating; must remain unconnected or tied to GND per layout best practice - no functional impact. |
| GND (Pin 4) | Ground reference | Common return path for IN, OUT, and internal circuitry; connects directly to thermal pad for optimal heat dissipation. |
| OUT (Pin 8) | Regulated output | Delivers stable 4.2 V; requires 0.47–10 µF ceramic capacitor to GND for loop stability and noise filtering. |
| Exposed pad | Thermal & electrical ground | Must be soldered to PCB copper pour for thermal conduction and EMI reduction; electrically connected to GND internally. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low IQ at full load | 5 µA typ. - enables >10-year battery life in 10 µA average-current IoT endpoints using two AA cells. |
| Ceramic capacitor compatible | Stable with 0.47–10 µF COUT - eliminates cost, size, and reliability penalties of tantalum/electrolytic capacitors. |
| Integrated short-circuit protection | 120 mA typical current limit - prevents damage during output faults without external current-sense circuitry. |
| Wide operating temperature | –40 °C to +125 °C junction - qualified for under-hood automotive sensors and industrial control cabinets without derating. |
| Low-noise output | 210 µVRMS broadband noise - avoids post-regulation filtering for precision analog stages like op-amps or SAR ADC references. |
Applications
| Industrial Sensor Node | Li-ion Battery Monitor |
|---|---|
Use Scenario: Remote temperature/humidity sensor powered by 3.7 V Li-ion cell with 12 V auxiliary backup bus. IC Role / Device Role / Timing Role: Primary 4.2 V rail regulator supplying MCU, BLE radio, and analog front-end. Use Value: 5 µA quiescent current extends battery life to >5 years in sleep mode; 24 V max input handles backup supply without external buck converter. | Use Scenario: Fuel gauge IC and protection circuit in portable medical device with single-cell Li-ion pack. IC Role / Device Role / Timing Role: Provides clean, accurate 4.2 V reference for ADC and charge management logic. Use Value: ±2% output accuracy over temperature ensures consistent cell voltage measurement; low noise avoids ADC quantization errors. |
| Smart Meter Auxiliary Rail | Automotive Body Control Module |
Use Scenario: Secondary 4.2 V supply for real-time clock, secure element, and tamper-detection circuitry in electricity meter. IC Role / Device Role / Timing Role: Always-on LDO powering security-critical peripherals independent of main 3.3 V domain. Use Value: 125 °C rating supports operation inside sealed meter enclosures; 57 dB SVR rejects noise from PLC communication lines. | Use Scenario: Low-power wake-up controller in door module, monitoring buttons and sensors while vehicle is off. IC Role / Device Role / Timing Role: Regulates 4.2 V rail for CAN transceiver standby and microcontroller RTC during sleep. Use Value: 500 mV dropout enables operation down to 4.7 V battery voltage - critical for cold-cranking scenarios where battery dips below 6 V. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| Torex XC6219B422MR-G | 4.2 V fixed, 100 mA output, 250 mV dropout at 100 mA, 1 µA IQ - lower dropout but lower current rating and narrower VIN (2.0–6.0 V). | Not suitable for 24 V industrial inputs; limited to single-cell battery or post-buck applications. | Select only if input stays ≤6 V and <100 mA load is required; otherwise insufficient VIN range. |
| Analog Devices ADM7172ACPZ-4.2-R7 | 4.2 V fixed, 2 A output, 150 mV dropout at 2 A, 2.2 mA IQ - much higher current and lower dropout, but 440× higher quiescent current. | Overqualified for low-power use; excessive IQ negates battery life benefits in always-on systems. | Choose only when >100 mA load or sub-200 mV dropout is mandatory; avoid for battery longevity-critical designs. |
Compared with XC6219B422MR-G and ADM7172ACPZ-4.2-R7, the LDK715PU42R uniquely balances ultra-low IQ (5 µA), wide VIN (4.3–24 V), and adequate 85 mA output - making it optimal for industrial battery-backed systems where runtime and input flexibility outweigh raw current capability.
Availability
LDK715PU42R is available at Aetrix Electronics and suitable for industrial sensor nodes, Li-ion battery monitors, smart meter auxiliary rails, and automotive body control modules requiring stable component supply across extended temperature and input voltage ranges.
Supply support for LDK715PU42R 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 analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.
The LDK715 series belongs to ST's high-voltage, ultra-low-IQ LDO product line, engineered specifically for battery-powered and wide-input industrial systems where efficiency, thermal robustness, and long-term reliability are non-negotiable.
FAQ
What is the minimum input voltage required for regulation at 4.2 V output?
The LDK715PU42R requires a minimum input voltage of 4.3 V to maintain regulation at 4.2 V output, as specified in its absolute maximum ratings and electrical characteristics table. Below this, the device enters dropout and output voltage drops linearly with input.
Can the LDK715PU42R operate with a 0.22 µF ceramic output capacitor?
No - the datasheet specifies a minimum output capacitance of 0.47 µF for stability with ceramic capacitors. Using 0.22 µF risks oscillation or poor transient response due to insufficient phase margin in the control loop.
Is the exposed thermal pad on the DFN8 package electrically connected?
Yes - the exposed pad is internally connected to GND and must be soldered to a PCB ground plane. It serves both thermal dissipation and electrical grounding functions; leaving it floating degrades thermal performance and may increase EMI.
Does the LDK715PU42R include an enable pin?
No - the LDK715PU42R has no enable (EN) pin. It operates continuously when input voltage exceeds 4.3 V. For controlled startup, external circuitry such as a MOSFET switch or dedicated enable supervisor is required.
LDK715PU42R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- 8-VDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 24V
- Voltage - Output (Min/Fixed):
- 4.2V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 1V @ 85mA
- Current - Output:
- 85mA
- Current - Quiescent (Iq):
- 7 µA
- Current - Supply (Max):
- 8.5 µA
- PSRR:
- 57dB ~ 38dB (100kHz ~ 1kHz)
- Control Features:
- -
- Protection Features:
- Over Current, Over Temperature
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-QFN (3x3)
LDK715PU42R FAQ
1.How can I place an order for LDK715PU42R through Aetrix?
Please submit a Request for Quotation (RFQ) for LDK715PU42R 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 LDK715PU42R reliable?
The price and inventory of LDK715PU42R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LDK715PU42R is usually 5 days.
3.What payment methods are accepted for LDK715PU42R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LDK715PU42R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LDK715PU42R?
LDK715PU42R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LDK715PU42R 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 LDK715PU42R?
For technical support, including LDK715PU42R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LDK715PU42R requirements.
6.How does Aetrix verify that LDK715PU42R is sourced from the original manufacturer or authorized distributors?
All LDK715PU42R 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 LDK715PU42R meets industry standards.
7.What is the process for return or replacement of LDK715PU42R?
All LDK715PU42R units undergo pre-shipment inspection (PSI). If there is an issue with LDK715PU42R, 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 LDK715PU42R part is unused and in its original packaging.
Return procedure for LDK715PU42R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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