3-A LDO is easily paralleled for high output current without any hot spots

February 09, 2011 // Paul Buckley

Linear Technology Corporation has unveiled a 3 A LDO that can be paralleled for heat spreading and higher output current, and is adjustable with a single resistor. The LT3083 regulator is based on the same innovative architecture as its 1.1 A predecessor, the LT3080, which uses a current source reference for single resistor output voltage setting. With the SET pins tied together, sharing the current and spreading the heat is accomplished between multiple regulators using a small length of PC trace as ballast, enabling multi-amp linear regulation in all surface-mount systems without heat sinks.

The LT3083 achieves unmatched regulation of under 2 mV at any output voltage. Featuring wide input voltage range from 1.2 V to 18 V (DD-Pak and TO-220 packages), the full current dropout is only 310 mV (when operating with a separate bias supply). The output voltage is programmable with a single resistor from 0V to 17.5 V, and the on-chip trimmed 50 µA current reference is trimmed to ±1%.

The regulation and output noise (40 µVrms) is independent of output voltage due to the device’s voltage follower architecture. The high output current, wide VIN and VOUT capability, tight line and load regulation, high ripple rejection, low external parts count and paralleling capability make the LT3083 ideal for modern higher-current, multi-rail systems.


Availability and Pricing

The LT3083 is offered in a variety of thermally enhanced surface-mount compatible packages, including a low profile (0.75 mm) 12-lead 4 mm x 4 mm DFN and a 16-lead thermally enhanced TSSOP; both dissipate 2 W in surface mount applications with no heat sink.

The LT3083 is also available in 5-lead TO-220 and DD-Pak power packages for mounting to heat sinks for higher power dissipation. 1,000-piece pricing starts at $3.80, $4.40 and $10.26 for the DFN package in E, I and MP grades respectively, and at $3.93, $4.53 and $10.62 for the TSSOP package E, I and MP grades, respectively. 1k pricing for the TO-220 and DD-Pak power packages is at $4.13, $4.73 and $11.16 for the E, I and MP grades respectively.

More information about the LT3083 LDO at www.linear.com/3083

Visit Linear Technology at www.linear.com

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