LT3932 - 36V, 2A Synchronous Step-Down LED Driver

Features

  • ±1.5% LED Current Regulation
  • ±1.2% Output Voltage Regulation
  • 5000:1 PWM Dimming at 100Hz
  • 128:1 Internal PWM Dimming
  • Spread-Spectrum Frequency Modulation
  • Silent Switcher® Architecture for Low EMI
  • 3.6V to 36V Input Voltage Range
  • 0V to 36V LED String Voltage
  • 2A, 36V Internal Switches
  • 200kHz to 2MHz with SYNC Function
  • 99.9% Maximum Duty Cycle
  • Analog or Duty Cycle LED Current Control
  • Open/Short LED Protection and Fault Indication
  • Accurate LED Current Sense with Monitor Output
  • Programmable UVLO
  • Thermally Enhanced 28-Pin (4mm × 5mm) QFN

Typical Application

LT3932 Typical Application
LT3932 Typical Application

Description

The LT3932 is a monolithic, synchronous, step-down DC/DC converter that utilizes fixed-frequency, peak current control and provides PWM dimming for a string of LEDs. The LED current is programmed by an analog voltage or the duty cycle of pulses at the CTRL pin. An output voltage limit can be set with a resistor divider to the FB pin.

The switching frequency is programmable from 200kHz to 2MHz by an external resistor at the RT pin or by an external clock at the SYNC/SPRD pin. With the optional spread spectrum frequency modulation enabled, the frequency varies from 100% to 125% to reduce EMI. The LT3932 also includes a driver for an external, high side PMOS for PWM dimming and an internal PWM signal generator for analog control of PWM dimming when an external signal is not available.

Additional features include an LED current monitor, an accurate EN/UVLO pin threshold, open-drain fault reporting for open-circuit and short-circuit load conditions, and thermal shutdown.

Packaging

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LT3932EUFD#PBF 4x5 QFN-28 UFD E 05-08-1712 Yes
LT3932EUFD#TRPBF 4x5 QFN-28 UFD E 05-08-1712 Yes
LT3932HUFD#PBF 4x5 QFN-28 UFD H 05-08-1712 Yes
LT3932HUFD#TRPBF 4x5 QFN-28 UFD H 05-08-1712 Yes
LT3932IUFD#PBF 4x5 QFN-28 UFD I 05-08-1712 Yes
LT3932IUFD#TRPBF 4x5 QFN-28 UFD I 05-08-1712 Yes


LT3932 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3932EUFD#PBF 4x5 QFN-28 E $5.64 $3.95 Yes
LT3932EUFD#TRPBF 4x5 QFN-28 E $5.70 $4.01 Yes
LT3932HUFD#PBF 4x5 QFN-28 H $6.57 $4.60 Yes
LT3932HUFD#TRPBF 4x5 QFN-28 H $6.63 $4.66 Yes
LT3932IUFD#PBF 4x5 QFN-28 I $6.22 $4.35 Yes
LT3932IUFD#TRPBF 4x5 QFN-28 I $6.28 $4.41 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Click here to view our complete list of demo boards

Applications

  • Automotive Lighting
  • Industrial and General Purpose Light

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

Technical Support