DC2838A: 250V @ 10 mA, 9 ~ 30V in

DC2838A features the LT®8365 in a boost configuration. It operates with a switching frequency of 400kHz and is designed to convert a 9V to 30V source to 250V, with 10mA output current.

The demo board contains an optional third charge pump stage for applications requiring higher output voltages. If needed, remove R14 and install optional components. Output voltage sensing connections remain the same.

The LT8365 can be used for different topologies with input voltages up to 60V. However, component selection in this demo circuit restricts the input voltage to 30V.

The demo board contains a selectable jumper, JP1, to aid in the selection of the desired sync pin mode of operation. The default setting is Burst Mode® operation.

This layout is optimized for good EMI performance and small solution size. Input and output filters are necessary for CISPR 25 Class 5 emissions. Radiated emissions plots are included in this manual.

The LT®8365 is a current mode DC/DC converter with a 1.5A, 150V switch operating from a 2.8V to 60V input. With a unique single feedback pin architecture it is capable of boost, SEPIC or inverting configurations. Burst Mode operation consumes as low as 9µA quiescent current to maintain high efficiency at very low output currents, while keeping typical output ripple below 15mV.

An external compensation pin allows optimization of loop bandwidth over a wide range of input and output voltages and programmable switching frequencies between 100kHz and 500kHz. A SYNC/MODE pin allows synchronization to an external clock. It can also be used to select between burst or pulse-skipping modes of operation with or without spread spectrum frequency modulation for low EMI. For increased efficiency, a BIAS pin can accept a second input to supply the INTVCC regulator. Additional features include frequency foldback and programmable soft-start to control inductor current during startup.