Maydori

Hello, I've a circuit shown like this image, that used to measure the current through shunt resistance , The circuit have analog & digital ground , the terminals 1 ,2 ,3 are for AC source . I need to protect this circuit from shorts . I actually try it out & booom kaboom happened !!! I lost an expensive chip !!! , this circuit operates UC, ft232rl ftdi , ADE7355 , lot of chips . So where's the right place to put the fuse ? & how to know that this is the right place ? Will be a fuse on the digital side and the analog side ? any other recommendation for this circuit ? I found out that 7805 voltage regulator is getting hot fast . R3 is shunt resistor with 200 u ohm resistance

Hi, I've attached a image of the current PMU setupusing the tps65721 to generate 3.3V on the DCDC converter and then produce 1.8V on the LDO and I just wanted to verify that my design looks ok. In addition, there is a mode pin that I currently left floating which determines whether the regulator is in PWM mode or PFM mode. Is it ok to leave that floating or should I tie it to gnd/VDD? Great regards, Maydori