Flyback controllers provide high maximum junction temperature

Linear Technology has launched the H grade version of its LTC3805/-5 current mode programmable frequency flyback controllers.

The devices contain the features necessary to design single ended isolated and non isolated flyback converters for telecom, datacom, PoE, automotive and general housekeeping power supplies. The LTC3805/-5 incorporates a 40uA start-up current, which allows the use of a high value input resistor and a low value capacitor for low power dissipation and quick power supply start up. It has been designed for wide input voltage range applications and to enable users to have one power supply for both 48V (36 to 75V) and 24V (18 to 36V) nominal input systems. The operating frequency is selectable from 70 to 700kHz by one external resistor or for noise sensitive requirements the device can be synchronised to an external clock over the same range. With a standby quiescent current of 360uA, the LTC3805/-5 is suitable for automotive applications.