LT3437 - High Voltage 500mA, 200kHz Step-Down Switching Regulator with 100µA Quiescent Current

Features

  • Wide Input Range: 3.3V to 60V
  • Load Dump (Input Transient) Protection to 80V
  • 500mA Peak Switch Current
  • Burst Mode® Operation: 100µA Quiescent Current**
  • Low Shutdown Current: IQ < 1µA
  • Burst Mode Operation Defeat
  • 200kHz Switching Frequency
  • Saturating Switch Design: 0.8 Ohm On-Resistance
  • Peak Switch Current Maintained Over Full Duty Cycle Range*
  • 1.25V Feedback Reference Voltage
  • Easily Synchronizable
  • Soft-Start Capability
  • Small 10-Pin Thermally Enhanced DFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LT3437 Typical Application
LT3437 Typical Application
LT3437 Typical Application

Description

The LT3437 is a 200kHz monolithic buck switching regulator that accepts input voltages up to 80V. A high efficiency 500mA, 0.8 Ohm switch is included on the die along with all the necessary oscillator, control and logic circuitry. Current mode topology is used for fast transient response and good loop stability.

Innovative design techniques along with a new high voltage process achieve high efficiency over a wide input range. Efficiency is maintained over a wide output current range by employing Burst Mode operation at low currents, utilizing the output to bias the internal circuitry, and by using a supply boost capacitor to fully saturate the power switch. Burst Mode operation can be defeated by a logic high signal on the SYNC pin which results in lower light load ripple at the expense of light load efficiency. Patented circuitry maintains peak switch current over the full duty cycle range.* Shutdown reduces input supply current to less than 1µA. External synchronization can be implemented by driving the SYNC pin with logic-level inputs. A single capacitor from the CSS pin to the output provides a controlled output voltage ramp (soft-start).

The LT3437 is available in a low profile (0.75mm) 3mm × 3mm 10-pin DFN package or a 16-Pin TSSOP Package both with exposed pad leadframes for low thermal resistance.

*Protected by U.S. Patents including 6498466.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

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

Part Number Package Code Temp Package
Drawing
RoHS
LT3437EDD#PBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3437EDD#TRPBF 3x3 DFN-10 DD E 05-08-1699 Yes
LT3437EFE#PBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT3437EFE#TRPBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT3437HFE#PBF TSSOP-16 FE H 05-08-1663 (BC) Yes
LT3437HFE#TRPBF TSSOP-16 FE H 05-08-1663 (BC) Yes
LT3437IDD#PBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3437IDD#TRPBF 3x3 DFN-10 DD I 05-08-1699 Yes
LT3437IFE#PBF TSSOP-16 FE I 05-08-1663 (BC) Yes
LT3437IFE#TRPBF TSSOP-16 FE I 05-08-1663 (BC) Yes


LT3437 Package Drawing
LT3437 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
LT3437EDD#PBF 3x3 DFN-10 E $3.21 $2.25 Yes
LT3437EDD#TRPBF 3x3 DFN-10 E $2.35 Yes
LT3437EFE#PBF TSSOP-16 E $3.29 $2.30 Yes
LT3437EFE#TRPBF TSSOP-16 E $2.42 Yes
LT3437HFE#PBF TSSOP-16 H $4.29 $3.00 Yes
LT3437HFE#TRPBF TSSOP-16 H $3.06 Yes
LT3437IDD#PBF 3x3 DFN-10 I $3.86 $2.70 Yes
LT3437IDD#TRPBF 3x3 DFN-10 I $2.80 Yes
LT3437IFE#PBF TSSOP-16 I $3.93 $2.75 Yes
LT3437IFE#TRPBF TSSOP-16 I $2.87 Yes
Buy NowRequest Samples
* 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.

Part Number Description Price Documentation
DC1232A LT3437IFE Demo Board I HIGH VOLTAGE 500mA 200kHz BUCK CONVERTER WITH BURST MODE $100.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LT3437HFE#PBF TSSOP-16 H $4.29 $3.00 Yes
LT3437HFE#TRPBF TSSOP-16 H $3.06 Yes
LT3437IDD#PBF 3x3 DFN-10 I $3.86 $2.70 Yes
LT3437IDD#TRPBF 3x3 DFN-10 I $2.80 Yes
LT3437IFE#PBF TSSOP-16 I $3.93 $2.75 Yes
LT3437IFE#TRPBF TSSOP-16 I $2.87 Yes
Buy NowRequest Samples
* 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.

Applications

  • High Voltage Power Conversion
  • 14V and 42V Automotive Systems
  • Industrial Power Systems
  • Distributed Power Systems
  • Battery-Powered Systems
  • Powered Ethernet

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
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To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LT3437

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