SLUSER8C June 2022 – March 2023 UCC28C50 , UCC28C51 , UCC28C52 , UCC28C53 , UCC28C54 , UCC28C55 , UCC28C56H , UCC28C56L , UCC28C57H , UCC28C57L , UCC28C58 , UCC28C59 , UCC38C50 , UCC38C51 , UCC38C52 , UCC38C53 , UCC38C54 , UCC38C55
PRODUCTION DATA
VREF is the voltage reference for the error amplifier and also for many other internal circuits in the IC. The 5-V reference tolerance is ±1% for the UCC28C5x family. The high-speed switching logic uses VREF as the logic power supply. The reference voltage is divided down internally to 2.5 V ±1% and connected to the error amplifier's noninverting input for accurate output voltage regulation. The reference voltage sets the internal bias currents and thresholds for functions such as the oscillator upper and lower thresholds along with the overcurrent limiting threshold. The output short-circuit current is 55 mA (maximum). To avoid device over-heating and damage, do not pull VREF to ground as a means to terminate switching. For reference stability and to prevent noise problems with high-speed switching transients, bypass VREF to GND with a ceramic capacitor close to the IC package. A ceramic capacitor with a minimum value of 0.1 µF is required. Additional VREF bypassing is required for external loads on the reference. An electrolytic capacitor may also be used in addition to the ceramic capacitor.