36V monolithic 1A push-pull DC/DC transformer driver

September 23, 2014 // By Graham Prophet
LT3999 is a monolithic push-pull isolated DC/DC transformer driver with two 1A current-limited power switches.

The LT3999 operates over an input voltage range of 2.7V to 36V, is targeted for power levels up to 15W and can produce a wide range of output voltages for automotive, industrial, medical and military applications.

The programmable duty cycle and turns ratio of the transformer sets the output voltage. Several off-the-shelf transformers shown in the data sheet simplify the design. The switching frequency is adjustable from 50 kHz to 1 MHz and can be synchronised to an external clock. The LT3999 input operating voltage range is set with precise undervoltage and overvoltage lockouts. The supply current is reduced to less than 1 µA during shutdown. A user-defined RC time constant provides an adjustable soft-start capability by limiting the inrush current at start-up and an onboard cross-conduction prevention circuit increases reliability.

The LT3999 is available in thermally enhanced MSOP-10 and 3mm x 3mm DFN-10 packages, in all temperature ratings. Pricing starts at $2.75 (1000) for the E grade (-40°C to 125°C junction temperature)

Linear Technology; www.linear.com/product/LT3999