Date: 04/06/2010

6A, 2.5MHz, 42V step-up DC/DC Converter with fault protection from Linear

Linear Technology has unveiled the LT3579, a current mode, fixed frequency step-up DC/DC converter with integrated fault protection features for output shorts, input/output overvoltages, and overtemperature conditions. This converter incorporates two integrated 42V switches, a 3.4A master switch and a 2.6A slave switch, which can be tied together for a total current of 6A. It operates from an input voltage range of 2.5V to 16V, with transient protection to 40V and is suitable for applications with input sources ranging from a single-cell Li-Ion to automotive inputs. It is suggested for many local power supply designs as it can be configured as either a boost, SEPIC or an inverting converter. Due to its tiny externals it has a very compact footprint while minimizing solution cost.

The LT3579's switches has a Vce(sat) of 0.25V (tied together at 5.5A) and is said to deliver efficiencies up to 90%. This device can deliver up to 1.7A at 12V or 1.2A at -12V from a 5V input to both switches. For high voltage outputs, the LT3579's slave switch enables high power charge pump topologies. The switching frequency of the converter can be programmed using a single resistor or synchronized to an external clock between 200kHz and 2.5MHz therefore avoiding "noise critical" frequency bands. Undervoltage lockout (UVLO) is user adjustable and a single feedback resistor sets the output voltage. Other features include external synchronization capability and junction temperature monitoring.

For applications requiring higher output current, the LT3579-1 offers a CLKOUT pin signal that is 180°C out of phase with the internal oscillator, thus the device is suggested for multiphase applications.

Package:
LT3579EUF and LT3579-1EUF come in 4mm x 5mm QFN-20 packages.
LT3579EFE and LT3579-1EFE come in TSSOP-20 packages.

Operating temperature range: -40deg C to 125deg C.

Price:
LT3579EUF and LT3579-1EUF start at each US$3.30 for 1,000 piece quantities. LT3579EFE and LT3579-1EFE start at each US$3.45 for 1,000 piece quantities.
LT3579IUFD and LT3579-1IUFD start at each US$3.67 for 1,000 piece quantities.
LT3579IFE and LT3579-1IFE start at each US$3.83 for 1,000 piece quantities.

Available: Now

For more information, visit http://www.linear.com/pr/3579.