Current-mode PWM controller for isolated and non-isolated supplies
The UC2843DTR is a current-mode PWM controller from Texas Instruments that handles step-up, step-down, and step-up/step-down topologies including boost, buck, buck-boost, flyback, and forward converters. It drives a single transistor output with positive configuration and isolation capability, making it a fit for offline flyback supplies or DC-DC converters where galvanic isolation is required. Switching frequency reaches up to 500 kHz, and the maximum duty cycle of 97% allows wide input-to-output voltage ratios in boost and flyback stages.
Supply range, temperature grade, and control features
Operating from a 12 V to 28 V supply (Vcc/Vdd), the controller suits industrial and telecom bus rails where the input is already regulated to 24 V nominal. Frequency control is available as a control feature, allowing the designer to synchronize or adjust the switching frequency with an external RC network. Clock sync is not supported internally, so multiple converters in the same system must either free-run at different frequencies or use an external sync injection circuit.
Package, footprint, and procurement options
Supplied in tape-and-reel (TR) or cut-tape (CT) options, so it fits both volume pick-and-place lines and prototype bench runs.