UCC256304: TENTATIVE no use ACin

Hi Hiroshi-san,

Thanks for your interest in UCC256304. The startup process for UCC256304 entails charing up the VCC capacitance to ~26V from the HV pin. If the HV startup is not desired, I would recommend using UCC256303. UCC256303 does not have HV startup function and you can ground the HV pin on this device. UCC256303 has been used successfully in systems which have an auxiliary supply such as this.

Best Regards,
Ben Lough

Ben-san,

I said "tentative".

Customer board is Fuji-elec IC.

They want to compare IC by exchange.

If UCC256304 works without AC input, the efficiency competition is fare.

Can UCC256304 work only Vcc voltage on/off?

If the competition result is good for everythings, customer will select UCC256304.

Hi Hiroshi-san,

Can you help me understand why your customer will consider UCC256304 but not UCC256303? UCC256303 is designed for systems which plan to use an auxiliary supply. It uses HHC like UCC256304 and will give you very similar efficiency performance to UCC256304.

Best Regards,
Ben Lough

Ben-san,
By another reason, ( it is for Japan reason), customer cannot use UCC256303.