PWM controller for isolated and non-isolated topologies
The TL3842BD-8 is a current-mode PWM controller that handles boost, flyback, and forward converter topologies — the three most common configurations in off-line and DC-DC supplies where the output needs to be stepped up or inverted. It drives a single external power transistor with a duty cycle up to 96%, so it can regulate outputs close to the input rail without dropping out of pulse-skipping. The switching frequency reaches 500 kHz, which lets the designer shrink the magnetics and output capacitor compared to a 100 kHz design — useful when board space is tight.
Supply and temperature envelope
The controller runs from a 10 V to 30 V supply rail — wide enough to start directly from a rectified line voltage through a dropping resistor, or from a regulated auxiliary winding.
It is ROHS3 compliant, meeting the latest restriction on hazardous substances for EU and global markets.