Home
Power management
AC/DC & DC/DC converters (integrated FET)
Home
Power management
AC/DC & DC/DC converters (integrated FET)

LM20343

ACTIVE

4.5-36V, 3A Current Mode Synchronous Buck Regulator with Adjustable Frequency

alarmNotifications Order now
Data sheet

A newer version of this product is available

open-in-new Compare alternates
Same functionality with different pin-out to the compared device
TLVM13630 ACTIVE High-density, 3-V to 36-V input, 1-V to 6-V output, 3-A step-down power module Save board space, simplify design and speed time to market with an integrated-inductor power module.

LM20343

ACTIVE
Data sheet Order now

Product details

Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 3 Vin (min) (V) 4.5 Vin (max) (V) 36 Switching frequency (min) (kHz) 250 Switching frequency (max) (kHz) 1000 Features Adjustable current limit, Enable, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, Tracking Control mode current mode Vout (min) (V) 0.8 Vout (max) (V) 32 Iq (typ) (µA) 2300 Duty cycle (max) (%) 80
Rating Catalog Operating temperature range (°C) -40 to 125 Topology Buck Type Converter Iout (max) (A) 3 Vin (min) (V) 4.5 Vin (max) (V) 36 Switching frequency (min) (kHz) 250 Switching frequency (max) (kHz) 1000 Features Adjustable current limit, Enable, Over Current Protection, Power good, Pre-Bias Start-Up, Synchronous Rectification, Tracking Control mode current mode Vout (min) (V) 0.8 Vout (max) (V) 32 Iq (typ) (µA) 2300 Duty cycle (max) (%) 80
HTSSOP (PWP) 20 41.6 mm² 6.5 x 6.4
  • 4.5V to 36V Input Voltage Range
  • 3A Output Current, 5.2A Peak Current
  • 130 mΩ/110 mΩ Integrated Power MOSFETs
  • 94% Peak Efficiency with Synchronous Rectification
  • 1.5% Feedback Voltage Accuracy
  • Current Mode Control, Selectable Compensation
  • Resistor Programmed, 1MHz Capable Oscillator
  • Adjustable Output Voltage Down to 0.8V
  • Compatible with Pre-biased Loads
  • Programmable Soft-start with External Capacitor
  • Precision Enable Pin with Hysteresis
  • OVP, UVLO Inputs and PGOOD Output
  • Internally Protected with Peak Current Limit, Thermal Shutdown and Restart
  • Accurate Current Limit Minimizes Inductor Size
  • Non-linear Current Mode Slope Compensation
  • 20-Pin HTSSOP Exposed Pad Package

All trademarks are the property of their respective owners.

  • 4.5V to 36V Input Voltage Range
  • 3A Output Current, 5.2A Peak Current
  • 130 mΩ/110 mΩ Integrated Power MOSFETs
  • 94% Peak Efficiency with Synchronous Rectification
  • 1.5% Feedback Voltage Accuracy
  • Current Mode Control, Selectable Compensation
  • Resistor Programmed, 1MHz Capable Oscillator
  • Adjustable Output Voltage Down to 0.8V
  • Compatible with Pre-biased Loads
  • Programmable Soft-start with External Capacitor
  • Precision Enable Pin with Hysteresis
  • OVP, UVLO Inputs and PGOOD Output
  • Internally Protected with Peak Current Limit, Thermal Shutdown and Restart
  • Accurate Current Limit Minimizes Inductor Size
  • Non-linear Current Mode Slope Compensation
  • 20-Pin HTSSOP Exposed Pad Package

All trademarks are the property of their respective owners.

The LM20343 is a full featured synchronous buck regulator capable of delivering up to 3A of load current. The current mode control loop is externally compensated with only two components, offering both high performance and ease of use. The device is optimized to work over the input voltage range of 4.5V to 36V making it well suited for high voltage systems.

The device features internal Over Voltage Protection (OVP) and Over Current Protection (OCP) circuits for increased system reliability. A precision Enable pin and integrated UVLO allows the turn on of the device to be tightly controlled and sequenced. Startup inrush currents are limited by both an internally fixed and externally adjustable soft-start circuit. Fault detection and supply sequencing are possible with the integrated power good (PGOOD) circuit.

The frequency of this device can be adjusted from 250 kHz to 1.0 MHz by connecting an external resistor from the RT pin to ground.

The LM20343 is designed to work well in multi-rail power supply architectures. The output voltage of the device can be configured to track a higher voltage rail using the SS/TRK pin. If the output of the LM20343 is pre-biased at startup it will not sink current to pull the output low until the internal soft-start ramp exceeds the voltage at the feedback pin.

The LM20343 is offered in an exposed pad 20-pin HTSSOP package that can be soldered to the PCB, eliminating the need for bulky heatsinks.

The LM20343 is a full featured synchronous buck regulator capable of delivering up to 3A of load current. The current mode control loop is externally compensated with only two components, offering both high performance and ease of use. The device is optimized to work over the input voltage range of 4.5V to 36V making it well suited for high voltage systems.

The device features internal Over Voltage Protection (OVP) and Over Current Protection (OCP) circuits for increased system reliability. A precision Enable pin and integrated UVLO allows the turn on of the device to be tightly controlled and sequenced. Startup inrush currents are limited by both an internally fixed and externally adjustable soft-start circuit. Fault detection and supply sequencing are possible with the integrated power good (PGOOD) circuit.

The frequency of this device can be adjusted from 250 kHz to 1.0 MHz by connecting an external resistor from the RT pin to ground.

The LM20343 is designed to work well in multi-rail power supply architectures. The output voltage of the device can be configured to track a higher voltage rail using the SS/TRK pin. If the output of the LM20343 is pre-biased at startup it will not sink current to pull the output low until the internal soft-start ramp exceeds the voltage at the feedback pin.

The LM20343 is offered in an exposed pad 20-pin HTSSOP package that can be soldered to the PCB, eliminating the need for bulky heatsinks.
filter Find other AC/DC & DC/DC converters (integrated FET)
Download View video with transcript Video

Technical documentation

star =Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 4
Type Title Date
* Data sheet LM20343 36V, 3A Adjustable Frequency Synchronous Buck Regulator datasheet (Rev. B) 03 Apr 2013
Selection guide Power Management Guide 2018 (Rev. R) 25 Jun 2018
EVM User's guide AN-1792 LM20343 Evaluation Board (Rev. B) 05 May 2013
Application note AN-2077 LM20k POL Module (Rev. A) 03 May 2013

Design & development

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

Evaluation board

LM20343EVAL — Evaluation Board for the LM20343

This evaluation board provides a solution to examine the full featured LM20343 buck switching regulator that is capable of driving up to 3A of load current. The device features a frequency adjust pin that allows the switching frequency to be adjusted from 250 kHz to 1.0 MHz. This board is capable (...)

User guide: PDF
Calculation tool

LM20343DESIGN-CALC — LM20343 Calculator spreadsheet

Supported products & hardware

Supported products & hardware

Products
AC/DC & DC/DC converters (integrated FET)
LM20343 — 4.5-36V, 3A Current Mode Synchronous Buck Regulator with Adjustable Frequency
Download
Package Pins CAD symbols, footprints & 3D models
HTSSOP (PWP) 20 Ultra Librarian
TI's Standard Terms and Conditions for Evaluation Items apply.

Ordering & quality

Information included:
  • RoHS
  • REACH
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring
Information included:
  • Fab location
  • Assembly location

Support & training

TI E2E™ forums with technical support from TI engineers

View all forum topics

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​

Videos