SLUSF11C February 2023 – March 2024 UCC14341-Q1
PRODUCTION DATA
The VDD-VEE output is the main output of the module. The power stage operation is determined by the sensed VDD-VEE voltage on FBVDD pin. As shown in Figure 7-1, the VDD-VEE voltage is sensed through a voltage divider RFBVDD_TOP and RFBVDD_BOT. When FBVDD voltage stays below the turn-off threshold, roughly 10mV above the VFBVDD_REF, the power stage operates, delivers power to the secondary side and makes the VDD-VEE output voltage rise. After the output reaches the turn-off threshold, the power stage turns off. Output voltage drops because of the load current. After the output voltage drops below the turn-on threshold, roughly 10mV below the VFBVDD_REF, the power stage is turned on again. With the accurate voltage reference and hysteresis control, the VDD-VEE output voltage can be regulated with high accuracy. To improve the noise immunity, a small capacitor of 330pF should be added between FBVDD and VEE pins. Excessive capacitor slows down the hysteresis loop and can cause excessive output voltage ripple or even stability issue.