Date: 09/10/2008

Current reference based LDO with unique features

Linear Technology Corporation introduced the LT3085, the NPN Low Drop Out linear regulator (LDO) that can be easily paralleled for heat spreading and are adjustable down to 0V with a single resistor.

This new regulator uses a current reference rather than a conventional voltage reference to allow sharing between multiple regulators by directly paralleling the pins. Current sharing is set with a small length of PC trace as ballast. This enables multi-amp linear regulation in all surface-mount systems without heat sinks.

The features of LT3085 are:

1. Outputs may be paralleled for higher output current or spreading PCB heat.
2. Low Dropout Voltage: 275mV at full load
3. Low output voltage noise: 33uVRMS over a bandwidth of 10Hz to 100kHz.
4. Stable 10uA Current Source Reference
5. Single-Resistor Programs VOUT
6. Adjustable output voltage range: 0V to 35V
7. Wide input voltage range: 1.2V to 36V
8. Output Current: 0.5A
9. Stable with Ceramic, Aluminum, or Tantalum Capacitors
10. Current Limiting with Foldback
11. Thermal Limiting.
12. The packages used can dissipate 1W to 2W in surface mount applications without a heat sink.
13. The LT3085E and LT3085I feature an operating junction temperature of -40°C to +125°C, while the LT3085MP (MSOP package only) features operation down to -55°C junction temperature.

Package: 6-Lead Low-Profile DFN (2mm x 3mm x 0.75mm) Package
Thermally enhanced 8-Lead MSOP Package
Price: (in 1K-piece)
$1.73 for LT3085E DFN package
$1.90 for LT3085I DFN package
$1.83 for LT3085E MSOP package
$2.00 for LT3085I MSOP package
$4.94 for LT3085MP MSOP package

For further details visit: http://www.linear.com