LTC3569 - Triple Buck Regulator with 1.2A and Two 600mA Outputs and Individual Programmable References

Features

  • Three Independent Current Mode Buck DC/DC Regulators (1.2A and 2 × 600mA)
  • Single Pin Programmable VFB Servo Voltages from 800mV Down to 425mV (in 25mV Steps)
  • Pull VFB High to Make Each 600mA Buck a Slave for Higher Current Operation
  • Pulse-Skipping or Burst Mode® Operation
  • Programmable Switching Frequency (1MHz to 3MHz) or Fixed 2.25MHz
  • Synchronizable (1.2MHz to 3MHz)
  • VIN Range 2.5V to 5.5V
  • All Regulators Internally Compensated
  • PGOOD Output Flag
  • Quiescent Current <100μA (All Regulators in Burst Mode Operation)
  • Zero Shutdown Current
  • Overtemperature and Short-Circuit Protection
  • Tiny 3mm × 3mm, 3mm × 4mm 20-Lead QFN and Thermally Enhanced TSSOP FE-16 Packages
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3569 Typical Application
LTC3569 Typical Application

Description

The LTC®3569 contains three monolithic, synchronous step-down DC/DC converters. Intended for medium power applications, it operates over a 2.5V to 5.5V input voltage range. The operating frequency is adjustable from 1MHz to 3MHz, allowing the use of tiny, low cost capacitors and inductors. The three output voltages are independently programmable by toggling the EN pins up to 15 times, lowering the 800mV FB references by 25mV per cycle. The first buck regulator sources load currents up to 1200mA. The other two buck regulators each provide 600mA.

The two 600mA buck regulators can also be configured to operate as slave power stages, running in parallel with another internal buck regulator to supply higher load currents. When operating as parallel, slave output stages, discrete external components are shared and available output currents sum together.

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
LTC3569EFE#PBF TSSOP-16 FE E 05-08-1663 (BA) Yes
LTC3569EFE#TRPBF TSSOP-16 FE E 05-08-1663 (BA) Yes
LTC3569EUD#PBF 3x3 QFN-20 UD E 05-08-1720 Yes
LTC3569EUD#TRPBF 3x3 QFN-20 UD E 05-08-1720 Yes
LTC3569EUDC#PBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3569EUDC#TRPBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3569IFE#PBF TSSOP-16 FE I 05-08-1663 (BA) Yes
LTC3569IFE#TRPBF TSSOP-16 FE I 05-08-1663 (BA) Yes
LTC3569IUD#PBF 3x3 QFN-20 UD I 05-08-1720 Yes
LTC3569IUD#TRPBF 3x3 QFN-20 UD I 05-08-1720 Yes
LTC3569IUDC#PBF 3x4 QFN-20 UDC I 05-08-1742 Yes
LTC3569IUDC#TRPBF 3x4 QFN-20 UDC I 05-08-1742 Yes


LTC3569 Package Drawing
LTC3569 Package Drawing
LTC3569 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
LTC3569EFE#PBF TSSOP-16 E $4.57 $3.20 Yes
LTC3569EFE#TRPBF TSSOP-16 E $3.26 Yes
LTC3569EUD#PBF 3x3 QFN-20 E $4.43 $3.10 Yes
LTC3569EUD#TRPBF 3x3 QFN-20 E $3.16 Yes
LTC3569EUDC#PBF 3x4 QFN-20 E $4.43 $3.10 Yes
LTC3569EUDC#TRPBF 3x4 QFN-20 E $3.16 Yes
LTC3569IFE#PBF TSSOP-16 I $5.36 $3.75 Yes
LTC3569IFE#TRPBF TSSOP-16 I $3.81 Yes
LTC3569IUD#PBF 3x3 QFN-20 I $5.22 $3.65 Yes
LTC3569IUD#TRPBF 3x3 QFN-20 I $3.71 Yes
LTC3569IUDC#PBF 3x4 QFN-20 I $5.22 $3.65 Yes
LTC3569IUDC#TRPBF 3x4 QFN-20 I $3.71 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
DC1340A LTC3569EUD Demo Board | Triple Buck Regulator with 1.2A and Two 600mA Outputs and Individual Programmable References $150.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

AEC-Q100 data is available for these specific part numbers. Please contact your local sales representative for more information regarding reliability reports 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
LTC3569IFE#PBF TSSOP-16 I $5.36 $3.75 Yes
LTC3569IFE#TRPBF TSSOP-16 I $3.81 Yes
LTC3569IUD#PBF 3x3 QFN-20 I $5.22 $3.65 Yes
LTC3569IUD#TRPBF 3x3 QFN-20 I $3.71 Yes
LTC3569IUDC#PBF 3x4 QFN-20 I $5.22 $3.65 Yes
LTC3569IUDC#TRPBF 3x4 QFN-20 I $3.71 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

  • Portable Applications with Multiple Supply Rails
  • General Purpose Step-Down DC/DC
  • Dynamic Voltage Scaling Applications

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email mylinear@linear.com with questions and comments.

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:

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

Models for the following parts are available in LTspice:
LTC3569

Technical Support