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Texas Instruments LM5166XDRCT
- Part No.:
- LM5166XDRCT
- Manufacturer:
- Texas Instruments
- Package:
- 10-VFDFN Exposed Pad
- Datasheet:
-
LM5166XDRCT.pdf
- Description:
- IC REG BUCK 5V 500MA 10VSON
- Quantity:
- Payment:
- Shipping:
Inventory:883
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Product details
Overview
LM5166XDRCT from Texas Instruments is a 3-V to 65-V input, 500-mA synchronous buck converter with fixed 5-V output, integrated 1-Ω P-channel high-side and 0.5-Ω N-channel low-side MOSFETs, 9.7-µA no-load quiescent current, and support for COT or PFM operation - used in industrial power rails and battery-powered systems requiring ultra-low IQ and wide VIN tolerance.
For engineers reviewing the LM5166XDRCT datasheet, LM5166XDRCT pinout, LM5166XDRCT application, or LM5166XDRCT equivalent, this page delivers verified technical context, validated pin functions, confirmed efficiency curves across 0.01–500 mA loads at VIN = 8 V to 65 V, and real-world alternative selection guidance for high-voltage buck replacement designs.
Technical Context
The LM5166XDRCT implements constant-on-time (COT) or pulse-frequency modulation (PFM) control without loop compensation, enabling fast transient response and stable operation across 3–65 V input with 5-V fixed output. Its integrated PFET/NFET power stage supports 100% duty cycle for ultra-low dropout and eliminates external Schottky diodes.
Key operational parameters include programmable peak current limit (200/300/500 mA), 900-µs internal soft-start or externally adjustable timing, open-drain PGOOD with 80–200 Ω on-resistance, and precision enable with 76-mV hysteresis. Thermal shutdown activates at 170°C with 10°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3 V to 65 V - enables direct replacement of high-voltage LDOs and operation from unregulated 24-V/48-V industrial or automotive rails. |
| Output Voltage | Fixed 5 V ±2% - internally trimmed; eliminates external feedback resistors and reduces BOM count. |
| Max Output Current | 500 mA - sustained DC load capability with thermal protection up to 150°C junction temperature. |
| No-Load Quiescent Current | 9.7 µA - enables multi-year battery life in always-on IoT sensors and remote monitoring devices. |
| Switching Frequency | Up to 600 kHz - allows compact 150-µH inductor and 47-µF output capacitor in space-constrained designs. |
| Efficiency at 100 mA / 24 VIN | 82% - measured per Figure 1; confirms high light-load efficiency critical for intermittent-duty applications. |
| Package | 10-pin VSON (3 mm × 3 mm, 0.5-mm pitch) - thermally enhanced layout with exposed pad for PCB heat sinking. |
Pinout & Package
LM5166XDRCT uses a 10-pin VSON package (DRC suffix) with 0.5-mm pitch and exposed thermal pad. The package supports high-power density layouts and requires GND-connected thermal pad for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 SW | Switching node | Internal drain connection of both PFET (high-side) and NFET (low-side); must connect directly to buck inductor with minimal trace inductance. |
| 2 VIN | Input supply rail | Primary power input for high-side MOSFET and internal bias LDO; requires local 2.2-µF ceramic capacitor with short PCB path. |
| 3 ILIM | Current limit programming | Resistor-to-GND sets peak current limit to 200/300/500 mA; determines inductor saturation margin and fault robustness. |
| 4 SS | Soft-start control | Open = 900-µs internal ramp; capacitor-to-GND extends ramp time; resistor-to-GND disables soft-start for immediate enable. |
| 5 RT | Mode select & frequency programming | Short to GND selects PFM; resistor-to-GND programs COT on-time and switching frequency up to 600 kHz. |
| 6 PGOOD | Power-good flag | Open-drain NFET output; requires 10–100-kΩ pullup to ≤12 V; asserts low when VOUT deviates >6% from regulation. |
| 7 EN | Enable input | Active-high logic; 1.22 V threshold with 76-mV hysteresis; supports precise UVLO sequencing in multi-rail systems. |
| 8 VOUT | Fixed output voltage node | Internally connected to 5-V feedback divider; serves as regulated output and reference point for PGOOD and sequencing. |
| 9 HYS | UVLO hysteresis control | Drain of internal NFET; external R-divider between HYS–EN–GND sets custom input UVLO thresholds and hysteresis. |
| 10 GND | Ground return | Power and signal ground; must be tied to exposed thermal pad and low-impedance system ground plane. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low IQ sleep mode | 9.7 µA at 12 VIN - extends battery runtime in always-on industrial sensors without compromising startup speed. |
| Integrated PFET/NFET power stage | 1-Ω high-side + 0.5-Ω low-side MOSFETs - eliminates external diode and bootstrap components; supports 100% duty cycle for <0.5-V dropout. |
| EMI-compliant design | Meets EN55022/CISPR 22 Class B - reduces need for external filtering in factory automation and building control equipment. |
| Diode emulation & pulse skipping | Enables >80% efficiency at 0.1 mA load - critical for low-power microcontroller bias supplies in energy-harvesting nodes. |
| No loop compensation required | Stable COT/PFM operation across all line/load conditions - cuts bill-of-materials by removing compensation network and simplifies layout. |
Applications
| Factory Automation Power | Automotive Body Control Module |
|---|---|
|
Use Scenario: Powering PLC I/O modules and fieldbus transceivers from 24-V industrial rails with strict EMI limits. IC Role / Device Role / Timing Role: Primary 5-V bias regulator delivering 300–500 mA with EN-controlled sequencing and PGOOD status reporting. Use Value: Eliminates need for discrete buck controller + external MOSFETs while meeting EN55022 radiated emissions requirements. |
Use Scenario: Supplying microcontrollers and CAN transceivers in 12-V/24-V automotive body electronics with cold-crank tolerance. IC Role / Device Role / Timing Role: High-input-voltage buck converter operating down to 3 V during cranking; provides regulated 5-V rail with thermal shutdown. Use Value: Sustains operation through 6-V cold-crank dips and delivers 500 mA without derating up to 125°C ambient. |
| High-Voltage LDO Replacement | Low-Power IoT Sensor Node |
|
Use Scenario: Replacing inefficient 78L05-style LDOs in 48-V telecom or industrial subsystems where power loss and heat are critical. IC Role / Device Role / Timing Role: Step-down regulator converting 48 V to 5 V at up to 500 mA with 85% efficiency at full load. Use Value: Reduces power dissipation from >2 W (LDO) to <0.8 W (LM5166XDRCT), eliminating heatsink requirement. |
Use Scenario: Providing regulated 5-V supply to BLE/Wi-Fi SoCs and analog front-ends in battery-powered environmental monitors. IC Role / Device Role / Timing Role: Ultra-low-IQ buck converter enabling multi-year operation on coin-cell or Li-SOCl₂ batteries. Use Value: 9.7-µA quiescent current extends shelf life and runtime; PFM mode maintains >75% efficiency at 10-µA load currents. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5165DRCT | Pin-to-pin compatible; identical 3–65 V input, but adjustable output (FB pin) and higher 600-mA rating. | Requires external resistor divider for 5-V output; better suited for designs needing multiple output voltages or future flexibility. | Select LM5165DRCT if adjustable VOUT or higher current headroom is needed; LM5166XDRCT saves BOM cost and layout area for fixed 5-V use. |
| TPS54202DRCT | Lower 3–28 V input range; 2-A output; requires external high-side MOSFET and loop compensation. | Targeted at higher-current, lower-voltage applications (e.g., 12-V input systems); lacks ultra-low IQ and wide-VIN capability. | Choose TPS54202DRCT only for 2-A loads below 28 V; LM5166XDRCT is superior for 3–65 V, 500-mA, low-IQ designs. |
Compared with LM5165DRCT and TPS54202DRCT, LM5166XDRCT uniquely combines 65-V max input, fixed 5-V output, 9.7-µA IQ, and integrated power FETs - making it the most compact, efficient, and cost-effective solution for high-input-voltage, low-power industrial and automotive bias rails.
Availability
LM5166XDRCT is available at Aetrix Electronics and suitable for factory automation, automotive body electronics, and high-voltage LDO replacement applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for LM5166XDRCT 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
Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and power management ICs, with decades of expertise in high-reliability power conversion solutions.
The LM5166XDRCT belongs to TI's high-voltage synchronous buck converter product line, designed specifically for industrial, automotive, and telecom applications demanding wide input range, ultra-low quiescent current, and minimal external components.
FAQ
What is the maximum input voltage rating for LM5166XDRCT?
The LM5166XDRCT has an absolute maximum input voltage rating of 68 V and a recommended operating maximum of 65 V. This allows reliable operation across harsh industrial and automotive environments including 48-V battery systems and unregulated 24-V/36-V rails. Operation above 65 V is not recommended for continuous use per TI's recommended operating conditions.
Does LM5166XDRCT require external compensation components?
No, LM5166XDRCT does not require external compensation components. Its constant-on-time (COT) and pulse-frequency modulation (PFM) control architectures provide inherent stability across all line and load conditions without loop compensation networks - reducing BOM count and simplifying PCB layout compared to traditional voltage-mode buck controllers.
How is the current limit configured on LM5166XDRCT?
The LM5166XDRCT current limit is configured via a resistor from the ILIM pin to GND. Three factory-trimmed settings are supported: 200 mA (R = 100 kΩ), 300 mA (R = 30.1 kΩ), or 500 mA (R = 0 Ω). This allows inductor selection optimization based on actual load requirements and thermal constraints without changing the IC itself.
Can LM5166XDRCT operate with 100% duty cycle?
Yes, LM5166XDRCT supports 100% duty cycle operation due to its integrated P-channel high-side MOSFET, which eliminates the need for a bootstrap capacitor. This enables ultra-low dropout performance - maintaining regulation even when VIN drops within ~0.5 V of the 5-V output, critical for cold-crank and brownout scenarios.
What is the thermal shutdown behavior of LM5166XDRCT?
LM5166XDRCT activates thermal shutdown at 170°C junction temperature with 10°C hysteresis, meaning it resumes operation only after cooling to ≤160°C. This protects the device during overload or poor heatsinking conditions while preventing rapid cycling. The 10-pin VSON package features an exposed thermal pad that must be soldered to a GND plane for effective heat dissipation.
LM5166XDRCT Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 10-VFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 65V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 500mA
- Frequency - Switching:
- 50kHz ~ 600kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-VSON (3x3)
LM5166XDRCT FAQ
1.How can I place an order for LM5166XDRCT through Aetrix?
Please submit a Request for Quotation (RFQ) for LM5166XDRCT 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 LM5166XDRCT reliable?
The price and inventory of LM5166XDRCT are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM5166XDRCT is usually 5 days.
3.What payment methods are accepted for LM5166XDRCT?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM5166XDRCT transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM5166XDRCT?
LM5166XDRCT orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM5166XDRCT 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 LM5166XDRCT?
For technical support, including LM5166XDRCT datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM5166XDRCT requirements.
6.How does Aetrix verify that LM5166XDRCT is sourced from the original manufacturer or authorized distributors?
All LM5166XDRCT 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 LM5166XDRCT meets industry standards.
7.What is the process for return or replacement of LM5166XDRCT?
All LM5166XDRCT units undergo pre-shipment inspection (PSI). If there is an issue with LM5166XDRCT, 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 LM5166XDRCT part is unused and in its original packaging.
Return procedure for LM5166XDRCT:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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