Product category:
Power Supply ICs and Controllers
News Release from: Linear Technology Corp | Subject: LT3825
Edited by the Electronicstalk Editorial
Team on 17 March 2006
Current mode controller boasts tight
regulation
The LT3825 is a synchronous flyback DC/DC controller with precision regulation and high efficiency for 10 to 60W or up to 12A output isolated power supplies.
Linear Technology has introduced the LT3825, a synchronous flyback DC/DC controller with precision regulation and high efficiency for 10 to 60W or up to 12A output isolated power supplies The LT3825 is a current mode controller that regulates the output voltage based on sensing secondary voltage via a transformer winding
This article was originally published on Electronicstalk on 28 Jul 2004 at 8.00am (UK)
Related stories
Card power chip meets smart and SIM standards
The LTC4557 is a dual SIM/smart-card power supply and level translator, which provides both 1.8 and 3V SIM power and digital signal level shifting from a 3 x 3mm QFN package.
RF mixers take transformers onboard
Linear Technology has released two new high linearity up-converting RF active mixers with integrated RF transformers.
This allows for tight output regulation without the use of an optoisolator, improving dynamic response and system reliability.
Synchronous rectification increases conversion efficiency and improves output cross regulation in multiple output power supplies.
For example, the LT3825 is used to convert an input supply of 36-72V to an isolated output of 3.3V at 12A with up to 90% efficiency and mere 0.009% regulation.
Applications include isolated power supplies in telecomms, medical, industrial and instrumentation systems.
The LT3825 has a unique feedback amplifier that eliminates the need for an optoisolator by sampling a transformer winding voltage during flyback period and using this voltage to precisely regulate the output voltage.
This alleviates the designer from spending time trimming the power supply.
Furthermore, the elimination of the optoisolater improves the output transient response.
A programmable primary gate delay function eliminates multiple discrete components from the circuit and optimises MOSFET switching time and transformer selection.
To further simplify the design, the LT3825 allows its switching frequency to be adjusted from 50 to 250kHz with a capacitor.
The IC can also be synchronised to an external oscillator.
The LT3825 is rated for operation from -40 to +125C and is offered in a thermally enhanced 16-lead TSSOP.
1000-piece price is set at $3.10 each. Request a free brochure from Linear Technology Corp ...
• Linear Technology Corp: contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
