I have a 5V DC input. I want to convert it into 3.3V DC. I'm trying to use VBT1-S5-S3.3-SMT DC/DC converter. I'm connecting my input to second pin of the converter. But it doesn't give 3.3V DC as output. When there is no load it gives 5V DC output on it's fifth pin. When I connect it to a circuit (when there is load) it produces different outputs. I tried couple of brand new converters, but neither of them worked. Am I doing something wrong? I can't use regulator, because the load circuit must be isolated. So Is there anything I can try?