The UC2836D is a high-frequency switching regulator, and proper layout and placement are crucial for its operation. TI recommends a 4-layer PCB with a solid ground plane, and the IC should be placed close to the input capacitors. The output inductor and diode should be placed close to the IC, and the output capacitor should be placed close to the load. A good layout will help reduce EMI and improve efficiency.
The inductor selection depends on the output current, output voltage, and switching frequency. TI recommends using an inductor with a low DC resistance (DCR) and a high saturation current. The inductor value should be chosen to ensure that the inductor current ripple is within 20-40% of the output current. TI provides an inductor selection guide in the datasheet, and online tools such as the TI Inductor Selection Tool can also be used.
The maximum junction temperature for the UC2836D is 150°C. However, it's recommended to keep the junction temperature below 125°C for reliable operation and to prevent thermal shutdown. The thermal resistance of the IC and the PCB, as well as the ambient temperature, should be considered when designing the thermal management system.
The UC2836D requires compensation to ensure stability. TI recommends using a Type II compensation network, which consists of a resistor, a capacitor, and an optional zero. The compensation values depend on the output voltage, output current, and switching frequency. TI provides a compensation calculator in the datasheet, and online tools such as the TI Power Stage Designer can also be used.
The input capacitor should be a low-ESR ceramic capacitor with a value of at least 10uF. The capacitor should be placed close to the IC and should be rated for the input voltage. TI recommends using a capacitor with a voltage rating of at least 1.5 times the input voltage. The input capacitor helps to filter the input voltage and reduce noise.
UC2836D datasheet
by Texas Instruments
