LT3837: Isolated No-Opto Synchronous Flyback Controller Data Sheet12/13/2012316K
Features and Benefits
- Senses Output Voltage Directly from Primary Side Winding—No Optoisolator Required
- Synchronous Driver for High Efficiency
- Supply Voltage Range 4.5V to 20V
- Accurate Regulation Without User Trims
- Programmable Switching Frequency from 50kHz to 250kHz
- Load Compensation
- Undervoltage Lockout
- Available in a Thermally Enhanced 16-Lead TSSOP Package
The LT3837 is an isolated switching regulator controller designed for medium power flyback topologies. A typical application is 10W to 60W with the part powered from a DC supply.
The LT3837 is a current mode controller that regulates an output voltage based on sensing the secondary voltage via a transformer winding during flyback. This allows for tight output regulation without the use of an optoisolator, improving dynamic response and reliability. Synchronous rectification increases converter efficiency and improves output cross regulation in multiple output converters.
The LT3837 operates in forced continuous conduction mode which improves cross regulation in multiple winding applications. Switching frequency is user programmable and can be externally synchronized. The part also has load compensation, undervoltage lockout and soft-start circuitry.
The LT3837 is available in a thermally enhanced 16-pin TSSOP package.
- Isolated Medium Power (10W to 60W) Supplies
- Instrumentation Power Supplies
- Isolated Medical Supplies
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (4)
Demonstration circuit 950A-B is an isolated, 30W multi-output, synchronous flyback converter in 1/8 brick format featuring the LT3837. Output voltage sensing is implemented without the use of opto-coupler, by sensing the voltage across a primary side auxiliary winding. A load compensation circuit is used to compensate for voltage drops caused by load currents. DC950A-B has input voltage range 9V-36V. Demonstration circuit 950A uses a transformer design with tapped secondary winding, to achieve higher efficiency and better cross regulation than is possible with a transformer that uses a separate winding for each output.
Demonstration circuit 1038A-A is a 33W isolated flyback converter with synchronous rectification and primary-side regulation featuring the LT3837. This circuit was designed to demonstrate the high levels of performance, efficiency, and small solution size attainable using the part in a flyback power supply. It operates at 200kHz and produces a regulated 3.3V, 10A output from an input voltage range of 9V to 36V. Isolation voltage is 1500VDC.
Demonstration circuit 1038A-C is a 36W isolated flyback converter with synchronous rectification and primary-side regulation featuring the LT3837. This circuit was designed to demonstrate the high levels of performance, efficiency, and small solution size attainable using the part in a flyback power supply. It operates at 200kHz and produces a regulated 12V, 3A output from an input voltage range of 9V to 36V. Isolation voltage is 1500VDC.
Demonstration circuit 1038A-B is a 35W isolated flyback converter with synchronous rectification and primary-side regulation featuring the LT3837. This circuit was designed to demonstrate the high levels of performance, efficiency, and small solution size attainable using the part in a flyback power supply. It operates at 200kHz and produces a regulated 5V, 7A output from an input voltage range of 9V to 36V. Isolation voltage is 1500VDC.
Documentation & Resources
R458 Reliability Data3/22/201831 K
DC1038A-B - Demo Manual2/19/2011484K
DC1038A-C - Demo Manual2/19/2011487K
DC1038A-A - Demo Manual2/19/2011305K
DC950A - Demo Manual9/24/2009345K
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|Part Number||Material Declaration||Reliability Data||Pin/Package Drawing||CAD Symbols, Footprints & 3D Models|
|LT3837EFE#PBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3837EFE#TRPBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3837IFE#PBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|LT3837IFE#TRPBF||Material Declaration||Reliability Data||16-Lead TSSOP w/ EP|
|Wafer Fabrication Data||R458 Reliability Data|
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