LTC3803-3

PRODUCTION

Constant Frequency Current Mode Flyback DC/DC Controller in ThinSOT

Part Models: 8
1ku List Price: Starting From $1.38

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Part Details

V_IN and V_OUT Limited Only by External Components
Adjustable Slope Compensation
Internal Soft-Start
–55°C to 150°C Operating Temperature Range
Constant Frequency 300kHz 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

The LTC3803-3 is a constant frequency current mode flyback controller optimized for driving N-channel MOSFETs in high input voltage applications. 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 LTC3803-3 provides ±1.5% output voltage accuracy and consumes only 240μA of quiescent current. Ground referenced current sensing allows LTC3803-3-based converters to accept input supplies beyond the LTC3803-3’s absolute maximum V_CC. A micropower hysteretic start-up feature allows efficient operation at high input voltages. For simplicity, the LTC3803-3 can also be powered from a high V_IN through a resistor, due to its internal shunt regulator. An internal undervoltage lockout shuts down the LTC3803-3 when the input voltage is too low to provide sufficient gate drive to the external MOSFET.

The LTC3803-3 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

Applications

Telecom Power Supplies
42V and 12V Automotive Power Supplies
Auxiliary/Housekeeping Power Supplies
Power over Ethernet Powered Devices

Part Models: 8
1ku List Price: Starting From $1.38

Documentation

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LTC3803ES6-3#TRMPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803ES6-3#TRPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803HS6-3#TRMPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803HS6-3#TRPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803IS6-3#TRMPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803IS6-3#TRPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803MPS6-3#TRMPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3803MPS6-3#TRPBF	6-Lead TSOT-23	Material Declaration Reliablity Data	Ultra Librarian SamacSys

This is the most up-to-date revision of the Data Sheet.

Tools & Simulations

LTspice 2

Models for the following parts are available in LTspice:

LTC3803
LTC3803-3
LTC3803-5

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

Evaluation Kits

LTC3803ES6-3 Isolated Demo Board | Flyback Controller, 18V ≤ VIN ≤ 72V, VOUT = 3.3V @ 3A

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Product Details

Demonstration circuit 1100 is an isolated Telecom DC/DC converter featuring the LTC3803ES6-3 constant frequency current mode flyback controller. The DC1100 converts 18V to 72V input into 3.3V output and provides 3A of output current. The 300KHz constant frequency operation is maintained down to light loads which reduces low frequency noise that occurs when power converters operate in pulse skipping mode. The converter provides high output voltage accuracy (typically ± 2%) over wide load range with no minimum load requirement.

Resources

DC1100A - Design File
488.00K

DC1100A - Demo Manual
152.00K

DC1100A - Schematic
27.00K

Latest Discussions

6 Years Ago

Part Details

Documentation

Data Sheet 1

Reliability Data 1

User Guide 1