A good PCB layout for the UC1875J883B involves keeping the input and output traces separate, using a solid ground plane, and placing the input and output capacitors close to the IC. Additionally, it's recommended to use a shielded inductor and to keep the switching node (pin 5) away from sensitive analog circuits.
The inductor value and type depend on the output voltage, current, and frequency of the converter. A good starting point is to use the inductor value recommended in the datasheet (e.g., 10uH for the UC1875J883B). For high-current applications, consider using a shielded inductor with a low DCR (DC resistance) and a high saturation current rating.
The UC1875J883B can dissipate up to 2.5W of power, so it's essential to ensure good thermal management. This can be achieved by using a heat sink, placing the IC on a thick copper plane, and keeping the ambient temperature below 70°C. Additionally, consider using a thermal interface material (TIM) to improve heat transfer between the IC and the heat sink.
To ensure stability, follow the recommended component values and PCB layout guidelines in the datasheet. Additionally, make sure to decouple the input and output pins with suitable capacitors, and use a compensation network (e.g., R-C network) to stabilize the feedback loop.
The UC1875J883B is a high-voltage, high-current switch-mode controller with a unique set of features, such as a built-in high-voltage regulator and a low-dropout linear regulator. Compared to other similar ICs, the UC1875J883B offers a higher input voltage range (up to 40V) and a higher output current capability (up to 3A).
UC1875J883B datasheet
by Texas Instruments
