The recommended layout and placement for the UCC2817AD involves keeping the high-frequency components (such as the transformer and the power MOSFETs) close to the IC, and using a solid ground plane to reduce EMI. The datasheet provides a recommended layout diagram, but it's also important to follow general PCB design best practices for high-frequency circuits.
Choosing the right transformer for the UCC2817AD involves considering factors such as the input voltage, output voltage, and power rating. The transformer should be designed to operate at the switching frequency of the UCC2817AD (typically around 100 kHz) and should have a turns ratio that matches the input and output voltage requirements. TI provides a transformer design guide and a list of recommended transformer vendors to help with the selection process.
The UCC2817AD has an operating temperature range of -40°C to 125°C, but the maximum junction temperature (TJ) is 150°C. It's important to ensure that the device is properly cooled and that the thermal design of the system is adequate to prevent overheating.
The UCC2817AD has a built-in OVP feature that can be enabled by connecting a resistor from the VCC pin to the OVP pin. The OVP threshold is set by the value of the resistor, and the device will shut down if the input voltage exceeds the threshold. Additional external circuitry may be required to provide hysteresis and to ensure that the device restarts properly after an OVP event.
While the UCC2817AD is typically used in isolated topologies such as flyback converters, it can also be used in non-isolated topologies such as buck converters. However, this requires careful consideration of the voltage ratings and the layout of the circuit to ensure that the device is properly biased and that the output voltage is within the safe operating range.
UCC2817AD datasheet
by Texas Instruments
