LT1976/LT1976B - High Voltage 1.5A, 200kHz Step-Down Switching Regulator with 100µA Quiescent Current

Features

  • Wide Input Range: 3.3V to 60V
  • 1.5A Peak Switch Current (LT1976)
  • 100µA Quiescent Current (LT1976)
  • 1.6mA Quiescent Current (LT1976B)
  • Low Shutdown Current: IQ < 1µA
  • Power Good Flag with Programmable Threshold
  • Load Dump Protection to 60V
  • 200kHz Switching Frequency
  • Saturating Switch Design: 0.2Ω On-Resistance
  • Peak Switch Current Maintained Over Full Duty Cycle Range
  • 1.25V Feedback Reference Voltage
  • Easily Synchronizable
  • Soft-Start Capability
  • Small 16-Pin Thermally Enhanced TSSOP Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LT1976 Typical Application
LT1976 Typical Application
LT1976 Typical Application

Description

The LT1976/LT1976B are 200kHz monolithic step-down switching regulators that accept input voltages up to 60V. A high efficiency 1.5A, 0.2Ω 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. The LT1976B does not shift into Burst Mode operation at low currents, eliminating low frequency output ripple at the expense of 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 devices also have a power good flag with a programmable threshold and time-out and thermal shutdown protection.

The LT1976/LT1976B are available in a 16-pin TSSOP package with Exposed Pad leadframe for low thermal resistance.

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
LT1976BEFE#PBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT1976BEFE#TRPBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT1976BIFE#PBF TSSOP-16 FE I 05-08-1663 (BC) Yes
LT1976BIFE#TRPBF TSSOP-16 FE I 05-08-1663 (BC) Yes
LT1976EFE#PBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT1976EFE#TRPBF TSSOP-16 FE E 05-08-1663 (BC) Yes
LT1976HFE#PBF TSSOP-16 FE H 05-08-1663 (BC) Yes
LT1976HFE#TRPBF TSSOP-16 FE H 05-08-1663 (BC) Yes
LT1976IFE#PBF TSSOP-16 FE I 05-08-1663 (BC) Yes
LT1976IFE#TRPBF TSSOP-16 FE I 05-08-1663 (BC) Yes


LT1976 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
LT1976BEFE#PBF TSSOP-16 E $5.00 $3.50 Yes
LT1976BEFE#TRPBF TSSOP-16 E $3.56 Yes
LT1976BIFE#PBF TSSOP-16 I $6.00 $4.20 Yes
LT1976BIFE#TRPBF TSSOP-16 I $4.26 Yes
LT1976EFE#PBF TSSOP-16 E $5.71 $4.00 Yes
LT1976EFE#TRPBF TSSOP-16 E $4.12 Yes
LT1976HFE#PBF TSSOP-16 H $6.93 $4.85 Yes
LT1976HFE#TRPBF TSSOP-16 H $4.97 Yes
LT1976IFE#PBF TSSOP-16 I $6.57 $4.60 Yes
LT1976IFE#TRPBF TSSOP-16 I $4.72 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
DC481A LT1976IFE Demo Board | 200kHz, 4V ≤ VIN ≤ 60V, 3.3Vout @ 1A $100.00
DC977A LT1976BEFE Demo Board | 200kHz, Non-Burst Mode, 4V ≤ VIN ≤ 60V, 3.3Vout @ 1A Contact Factory
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
LT1976BIFE#PBF TSSOP-16 I $6.00 $4.20 Yes
LT1976BIFE#TRPBF TSSOP-16 I $4.26 Yes
LT1976HFE#PBF TSSOP-16 H $6.93 $4.85 Yes
LT1976HFE#TRPBF TSSOP-16 H $4.97 Yes
LT1976IFE#PBF TSSOP-16 I $6.57 $4.60 Yes
LT1976IFE#TRPBF TSSOP-16 I $4.72 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

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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
  • Step 3: If LTspice does not automatically open after clicking the link above, you can instead run the simulation by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTspice and open the demonstration circuit by selecting 'Open' from the 'File' menu

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LT1976
LT1976B

Technical Support