48% duty ceiling sets the flyback transformer spec
The TL2845BDRG4-8 is a current-mode PWM controller from Texas Instruments, built for boost, flyback, and forward converter topologies. Its 48% maximum duty cycle is the hard limit for the transformer turns ratio in a flyback design — you cannot push past it for a wider input range without hitting pulse-skipping. The switching frequency runs up to 500 kHz, which lets you shrink the magnetics but demands a layout that keeps the sense-resistor loop tight.
Supply rails and temperature grade for industrial bias
Vcc runs from 7.6 V to 30 V — the undervoltage lockout threshold is built into that lower end, so the controller stays off until the bias rail is solid. The single transistor-driver output drives an external MOSFET directly; there is no synchronous rectifier on-chip, so the secondary-side rectifier is external.
SOIC-8 package and reflow considerations
No exposed pad — the die heat flows through the leadframe and into the board copper.