Texas Instruments recommends a compact layout with short traces, and placing the IC close to the power stage. Additionally, a solid ground plane and a separate analog ground plane can help reduce noise and EMI. Refer to the application note 'UCC3804 Layout and EMI Considerations' for more details.
The VREF pin capacitor value depends on the desired soft-start time and the output voltage. A larger capacitor value will result in a slower soft-start, while a smaller value will result in a faster soft-start. A good starting point is 10nF to 22nF. Refer to the datasheet's 'VREF Pin' section for more information.
The maximum allowed voltage on the VCC pin is 15V. Exceeding this voltage can damage the IC. It's recommended to use a voltage regulator or a zener diode to limit the voltage to 12V or less.
The UCC3804DTRG4 has a built-in OVP feature that can be enabled by connecting the OVP pin to a voltage divider network. The OVP threshold is set by the voltage on the OVP pin, which should be set to 1.5V to 2.5V above the maximum allowed output voltage. Refer to the datasheet's 'Overvoltage Protection' section for more information.
The RT pin is used to set the oscillator frequency. A resistor connected between the RT pin and the GND pin sets the oscillator frequency. The recommended value is 10kΩ to 20kΩ. Refer to the datasheet's 'RT Pin' section for more information.
UCC3804DTRG4 datasheet
by Texas Instruments
