LTC3803-5 - Constant Frequency Current Mode Flyback DC/DC Controller in ThinSOT

Features

  • VIN and VOUT Limited Only by External Components
  • 4.8V Undervoltage Lockout Threshold
  • Operating Junction Temperature from –55°C to 150°C
  • Adjustable Slope Compensation
  • Internal Soft-Start
  • Constant Frequency 200kHz Operation
  • ±1.5% Reference Accuracy
  • Current Mode Operation for Excellent Line and Load Transient Response
  • No Minimum Load Requirement
  • Low Quiescent Current: 240μA
  • Low Profile (1mm) SOT-23 Package
Designed for Automotive and Transportation Applications
AEC-Q100 data available for specific packages


Typical Application

LTC3803-5 Typical Application
LTC3803-5 Typical Application

Description

The LTC3803-5 is a constant frequency current mode flyback controller optimized for driving N-channel MOSFETs in high input voltage applications. The LTC3803-5 operates from inputs as low as 5V. Constant frequency operation is maintained down to very light loads, resulting in less low frequency noise generation over a wide range of load currents. Slope compensation can be programmed with an external resistor.

The LTC3803-5 provides ±1.5% output voltage accuracy and consumes only 240μA of quiescent current. Ground referenced current sensing allows LTC3803-5-based converters to accept input supplies beyond the LTC3803-5’s absolute maximum VCC. For simplicity, the LTC3803-5 can be powered from a high VIN through a resistor, due to its internal shunt regulator. An internal undervoltage lockout shuts down the IC when the input voltage is too low to provide sufficient gate drive to the external MOSFET.

The LTC3803-5 is available in a low profile (1mm) 6-lead SOT-23 (ThinSOT) package.

  Turn On Voltage
Frequency
LTC3803 8.7V 200kHz
LTC3803-3 8.7V 300kHz
LTC3803-5 4.8V 200kHz

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
LTC3803ES6-5#PBF SOT-23 S6 E 05-08-1636 Yes
LTC3803ES6-5#TRMPBF SOT-23 S6 E 05-08-1636 Yes
LTC3803ES6-5#TRPBF SOT-23 S6 E 05-08-1636 Yes
LTC3803HS6-5#PBF SOT-23 S6 H 05-08-1636 Yes
LTC3803HS6-5#TRMPBF SOT-23 S6 H 05-08-1636 Yes
LTC3803HS6-5#TRPBF SOT-23 S6 H 05-08-1636 Yes
LTC3803IS6-5#PBF SOT-23 S6 I 05-08-1636 Yes
LTC3803IS6-5#TRMPBF SOT-23 S6 I 05-08-1636 Yes
LTC3803IS6-5#TRPBF SOT-23 S6 I 05-08-1636 Yes
LTC3803MPS6-5#PBF SOT-23 S6 MP 05-08-1636 Yes
LTC3803MPS6-5#TRMPBF SOT-23 S6 MP 05-08-1636 Yes
LTC3803MPS6-5#TRPBF SOT-23 S6 MP 05-08-1636 Yes


LTC3803-5 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
LTC3803ES6-5#PBF SOT-23 E $1.60 Yes
LTC3803ES6-5#TRMPBF SOT-23 E $1.60 $1.17 Yes
LTC3803ES6-5#TRPBF SOT-23 E $1.60 $1.12 Yes
LTC3803HS6-5#PBF SOT-23 H $2.33 Yes
LTC3803HS6-5#TRMPBF SOT-23 H $2.33 $1.68 Yes
LTC3803HS6-5#TRPBF SOT-23 H $2.33 $1.63 Yes
LTC3803IS6-5#PBF SOT-23 I $1.87 Yes
LTC3803IS6-5#TRMPBF SOT-23 I $1.87 $1.36 Yes
LTC3803IS6-5#TRPBF SOT-23 I $1.87 $1.31 Yes
LTC3803MPS6-5#PBF SOT-23 MP $5.64 Yes
LTC3803MPS6-5#TRMPBF SOT-23 MP $5.64 $4.00 Yes
LTC3803MPS6-5#TRPBF SOT-23 MP $5.64 $3.95 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.

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
LTC3803HS6-5#PBF SOT-23 H $2.33 Yes
LTC3803HS6-5#TRMPBF SOT-23 H $2.33 $1.68 Yes
LTC3803HS6-5#TRPBF SOT-23 H $2.33 $1.63 Yes
LTC3803IS6-5#PBF SOT-23 I $1.87 Yes
LTC3803IS6-5#TRMPBF SOT-23 I $1.87 $1.36 Yes
LTC3803IS6-5#TRPBF SOT-23 I $1.87 $1.31 Yes
LTC3803MPS6-5#PBF SOT-23 MP $5.64 Yes
LTC3803MPS6-5#TRMPBF SOT-23 MP $5.64 $4.00 Yes
LTC3803MPS6-5#TRPBF SOT-23 MP $5.64 $3.95 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

  • 42V and 12V Automotive Power Supplies
  • Telecom Power Supplies
  • Auxiliary/Housekeeping Power Supplies
  • Power Over 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

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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:
LTC3803
LTC3803-3
LTC3803-5

Technical Support