The UC2845D8TR is a high-frequency switching regulator, and as such, proper PCB layout and design are crucial for optimal performance. TI recommends a multi-layer PCB with a solid ground plane, and to keep the switching node (pin 5) as short as possible. Additionally, decoupling capacitors should be placed close to the IC, and the input and output capacitors should be placed close to the switching node.
The choice of inductor value and type depends on the specific application requirements, such as output voltage, current, and switching frequency. TI recommends using an inductor with a high saturation current rating and a low DC resistance. A good starting point is to use an inductor with a value between 10uH to 22uH, and to consult the datasheet for more detailed guidance.
The UC2845D8TR is rated for operation from -40°C to 125°C, but the maximum ambient temperature range depends on the specific application and the thermal design. TI recommends using a thermal derating curve to determine the maximum ambient temperature for a given application.
To ensure EMC compliance, TI recommends using a shielded enclosure, keeping the switching node (pin 5) as short as possible, and using a common-mode choke or ferrite bead on the input and output lines. Additionally, the PCB layout should be designed to minimize radiated emissions and conducted noise.
The recommended input capacitor type is a low-ESR ceramic or film capacitor, with a value between 10uF to 22uF. The capacitor should be placed close to the IC and should have a voltage rating that exceeds the maximum input voltage.
UC2845D8TR datasheet
by Texas Instruments
