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LM5166

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3V-65V Input, 500mA Synchronous Buck Converter With Ultra-Low Iq

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Data sheet

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Same functionality with different pin-out to the compared device
LMR36506 ACTIVE 3-V to 65-V, 0.6-A ultra-small synchronous buck converter with 4 μA IQ Smaller footprint, lower IQ and lower EMI.
TPSM365R6 ACTIVE 3-V to 65-V input, 1-V to 13-V output, 0.6-A synchronous buck converter power module Smaller design with an integrated-inductor power module.

LM5166

ACTIVE
Data sheet Order now

Product details

Rating Catalog Operating temperature range (°C) -40 to 150 Topology Buck Type Converter Iout (max) (A) 0.5 Vin (min) (V) 3 Vin (max) (V) 65 Switching frequency (min) (kHz) 50 Switching frequency (max) (kHz) 600 Features Adjustable current limit, Enable, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, UVLO adjustable Control mode Constant on-time (COT) Vout (min) (V) 1.23 Vout (max) (V) 65 Iq (typ) (µA) 10 Duty cycle (max) (%) 100
Rating Catalog Operating temperature range (°C) -40 to 150 Topology Buck Type Converter Iout (max) (A) 0.5 Vin (min) (V) 3 Vin (max) (V) 65 Switching frequency (min) (kHz) 50 Switching frequency (max) (kHz) 600 Features Adjustable current limit, Enable, Light Load Efficiency, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, UVLO adjustable Control mode Constant on-time (COT) Vout (min) (V) 1.23 Vout (max) (V) 65 Iq (typ) (µA) 10 Duty cycle (max) (%) 100
VSON (DRC) 10 9 mm² 3 x 3
  • Wide Input Voltage Range of 3 V to 65 V
  • 9.7-µA No-Load Quiescent Current
  • –40°C to 150°C Junction Temperature Range
  • Fixed (3.3-V, 5-V) or Adjustable VOUT Options
  • Meets EN55022 / CISPR 22 EMI Standards
  • Integrated 1-Ω PFET Buck Switch
    • Supports 100% Duty Cycle for Low Dropout
  • Integrated 0.5-Ω NFET Synchronous Rectifier
    • Eliminates External Schottky Diode
  • Programmable Peak Current Limit Supports:
    • 500-mA, 300-mA, or 200-mA Loads
  • Selectable PFM or COT Mode Operation
  • 1.223-V ±1.2% Internal Voltage Reference
  • Switching Frequency up to 600 kHz
  • 900-µs Internal or Externally-Adjustable Soft Start
  • Diode Emulation and Pulse Skipping for Ultra-High Light-Load Efficiency
  • No Loop Compensation or Bootstrap Components
  • Precision Enable and Input UVLO With Hysteresis
  • Open-Drain Power Good Indicator
  • Thermal Shutdown Protection With Hysteresis
  • Pin-to-Pin Compatible With the LM5165
  • 10-Pin, 3-mm × 3-mm VSON Package
  • Create a Custom Regulator Design Using WEBENCH® Power Designer
  • Wide Input Voltage Range of 3 V to 65 V
  • 9.7-µA No-Load Quiescent Current
  • –40°C to 150°C Junction Temperature Range
  • Fixed (3.3-V, 5-V) or Adjustable VOUT Options
  • Meets EN55022 / CISPR 22 EMI Standards
  • Integrated 1-Ω PFET Buck Switch
    • Supports 100% Duty Cycle for Low Dropout
  • Integrated 0.5-Ω NFET Synchronous Rectifier
    • Eliminates External Schottky Diode
  • Programmable Peak Current Limit Supports:
    • 500-mA, 300-mA, or 200-mA Loads
  • Selectable PFM or COT Mode Operation
  • 1.223-V ±1.2% Internal Voltage Reference
  • Switching Frequency up to 600 kHz
  • 900-µs Internal or Externally-Adjustable Soft Start
  • Diode Emulation and Pulse Skipping for Ultra-High Light-Load Efficiency
  • No Loop Compensation or Bootstrap Components
  • Precision Enable and Input UVLO With Hysteresis
  • Open-Drain Power Good Indicator
  • Thermal Shutdown Protection With Hysteresis
  • Pin-to-Pin Compatible With the LM5165
  • 10-Pin, 3-mm × 3-mm VSON Package
  • Create a Custom Regulator Design Using WEBENCH® Power Designer

The LM5166 is a compact, easy-to-use, 3-V to 65-V, ultra-low IQ synchronous buck converter with high efficiency over wide input voltage and load current ranges. With integrated high-side and low-side power MOSFETs, up to 500 mA of output current can be delivered at fixed output voltages of 3.3 V or 5 V, or an adjustable output. The converter is designed to simplify implementation while providing options to optimize the performance for the target application. Pulse frequency modulation (PFM) mode is selected for optimal light-load efficiency or constant on-time (COT) control for nearly constant operating frequency. Both control schemes do not require loop compensation while providing excellent line and load transient response and short PWM on-time for large step-down conversion ratios.

The high-side P-channel MOSFET can operate at 100% duty cycle for lowest dropout voltage and does not require a bootstrap capacitor for gate drive. Also, the current limit setpoint is adjustable to optimize inductor selection for a particular load current requirement. Selectable and adjustable start-up timing options include minimum delay (no soft start), internally fixed (900 µs), and externally programmable soft start using a capacitor. An open-drain PGOOD indicator can be used for sequencing, fault reporting, and output voltage monitoring. The LM5166 is available in a 10-pin VSON package with 0.5-mm pin pitch.

The LM5166 is a compact, easy-to-use, 3-V to 65-V, ultra-low IQ synchronous buck converter with high efficiency over wide input voltage and load current ranges. With integrated high-side and low-side power MOSFETs, up to 500 mA of output current can be delivered at fixed output voltages of 3.3 V or 5 V, or an adjustable output. The converter is designed to simplify implementation while providing options to optimize the performance for the target application. Pulse frequency modulation (PFM) mode is selected for optimal light-load efficiency or constant on-time (COT) control for nearly constant operating frequency. Both control schemes do not require loop compensation while providing excellent line and load transient response and short PWM on-time for large step-down conversion ratios.

The high-side P-channel MOSFET can operate at 100% duty cycle for lowest dropout voltage and does not require a bootstrap capacitor for gate drive. Also, the current limit setpoint is adjustable to optimize inductor selection for a particular load current requirement. Selectable and adjustable start-up timing options include minimum delay (no soft start), internally fixed (900 µs), and externally programmable soft start using a capacitor. An open-drain PGOOD indicator can be used for sequencing, fault reporting, and output voltage monitoring. The LM5166 is available in a 10-pin VSON package with 0.5-mm pin pitch.
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Technical documentation

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Type Title Date
* Data sheet LM5166 3-V to 65-V Input, 500-mA Synchronous Buck Converter With Ultra-Low IQ datasheet (Rev. B) PDF | HTML 01 Jun 2017
Application note Step-Dwn (Buck) Convrtr Pwer Solutions for Programmable Logic Controller Systems (Rev. A) PDF | HTML 26 Jul 2021
Selection guide Buck Converter Quick Reference Guide (Rev. B) 08 Apr 2021
White paper Valuing wide VIN, low EMI synchronous buck circuits for cost-driven, demanding a (Rev. A) 10 Apr 2019
Application brief Powering Drones With a Wide VIN DC-DC Converter (Rev. A) 05 Feb 2019
Application note Selecting an Ideal Ripple Generation Network for Your COT Buck Converter (Rev. A) 15 Jun 2017
Technical article The power to innovate industrial design PDF | HTML 27 Mar 2017
EVM User's guide LM5166EVM-C50A Evaluation Module 08 Dec 2016
EVM User's guide LM5166EVM-C33A Evaluation Module 07 Dec 2016
Technical article Trends in building automation: predictive maintenance PDF | HTML 01 Nov 2016
Analog Design Journal Low-EMI buck powers a multivariable sensor transmitter with BLE connectivity 24 Oct 2016
Technical article Powering smart sensor transmitters in industrial applications PDF | HTML 02 May 2016
Technical article DC/DC converter datasheets - Quiescent current demystified: Part two PDF | HTML 11 Apr 2016
Analog Design Journal Accurately measuring efficiency of ultralow-IQ devices 22 Jan 2014

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Evaluation board

LM5166EVM-C33A — LM5166 Wide VIN, Low IQ, COT 3.3V 500mA Evaluation Module

The LM5166EVM-C33A evaluation module (EVM) is designed to showcase the performance and all features of the LM5166, wide-VIN, synchronous buck DC/DC buck converter with ultra-low no-load supply current. The design is packaged in a miniature footprint with low component count. It operates over a (...)
User guide: PDF
Not available on TI.com
Evaluation board

LM5166EVM-C50A — LM5166 Wide VIN, Low IQ, COT 5V 500mA Evaluation Module

The LM5166EVM evaluation module (EVM) is designed to showcase the performance and all features of the LM5166, wide-VIN, synchronous buck DC/DC buck converter with ultra-low no-load supply current. The design is packaged in a miniature footprint with low component count. It operates over a wide (...)
User guide: PDF
Not available on TI.com
Simulation model

LM5166 PSpice Transient Model (Rev. B)

SNVMAV8B.ZIP (104 KB) - PSpice Model
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Simulation model

LM5166 Unencrypted PSpice Transient Model (Rev. B)

SNVMAV7B.ZIP (5 KB) - PSpice Model
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Simulation model

LM5166X PSpice Transient Model (Rev. B)

SNVMAZ3B.ZIP (130 KB) - PSpice Model
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Simulation model

LM5166X Unencrypted PSpice Transient Model (Rev. B)

SNVMAZ2B.ZIP (5 KB) - PSpice Model
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Simulation model

LM5166Y PSpice Transient Model (Rev. B)

SNVMAZ1B.ZIP (124 KB) - PSpice Model
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Simulation model

LM5166Y Unencrypted PSpice Transient Model (Rev. B)

SNVMAZ0B.ZIP (5 KB) - PSpice Model
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Calculation tool

LM5166DESIGN-CALC — LM5166 DC/DC Converter Design Tool

Welcome to the LM5166 Quick-Start Design Tool. This standalone tool facilitates and assists the power supply engineer with design of a DC/DC buck converter based on the LM5166 low IQ synchronous buck DC/DC regulator. As such, the user can expeditiously arrive at an optimized design to meet the (...)
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Reference designs

TIDA-01395 — 24-V AC Power Stage With Wide Vin Converter and Battery Gauge Reference Design for Smart Thermostat

This reference design provides a low BOM count, high-efficiency power stage for smart thermostats and other gateway building automation designs. This power stage takes a 24-V AC input and produces a 5-V and 3.3-V output rail, which can power additional point-of-load converters if added. The (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01437 — RGB Signal Light With IO-Link Interface Reference Design

This reference design implements a five-segment LED smart stack light with 20 LEDs used in factory floor and industrial process automation of greater complexity. An IO-Link interface is implemented for controlling the stack light and reading back status information. The design features low power (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01487 — Isolated CAN Flexible Data (FD) Rate Repeater Reference Design

CAN and CANopen are legacy Fieldbus protocols used in many applications in factory automation. Whenever high voltage can damage the end equipment, there is need for isolation. This isolated CAN flexible data (FD) rate repeater reference design adds electrical isolation between two CAN (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01386 — Ultrasonic Distance Sensor with IO-Link Reference Design

This reference design features an ultrasonic distance sensor that fits in a M12 housing due to its high integration and an optimized layout. The design offers an IO-Link interface to communicate with the system control, which makes it industry 4.0 ready.  The purpose of ultrasonic (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-010055 — Non-isolated power architecture with diagnostics reference design for protection relay modules

This reference design showcases non-isolated power supply architectures for protection relays with analog input/output and communication modules generated from 5-, 12-, or 24-V DC input. To generate the power supplies the design uses DC/DC converters with an integrated FET, a power module with an (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-010049 — TUV-assessed digital input reference design for IEC 61508 (SIL-2)

This 8-channel, group-isolated, digital input module reference design, focuses on applications with the need for industrial functional safety. This design has diagnostics implemented to help detect both permanent and transient random hardware faults. The concept of this input module has been (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIPD215 — Less Than 1-W, Quad-Channel, Analog Output Module With Adaptive Power Management Reference Design

This quad-channel, analog output module delivers voltage and current outputs using the highly integrated DAC8775 digital-to-analog converter (DAC). Integrated adaptive power management, along with the LM5166 buck converter, reduces the total power dissipation of the reference design to less than 1 (...)
Design guide: PDF
Schematic: PDF
Reference designs

TIDA-01358 — 24-V AC Power Stage With Wide Vin Converter and Battery Backup Reference Design for Smart Thermostat

The TIDA-01358 reference design provides a low BOM cost, high efficiency power stage solution for smart thermostats and other gateway building automation end equipment. This power stage takes a 24Vac input and produces a 5V and 3.3V output rail which can power additional point-of-load converters (...)
Design guide: PDF
Schematic: PDF
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