UCC256303: EVM schematic inquiry

Renan Santos Adriano

Mastermind 22250 points

Part Number: UCC256303
Other Parts Discussed in Thread: UCC25630-1EVM-291, , UCC256301, UCC256403

Hello Team,

Good day.

My Customer is looking at the UCC25630-1EVM-291 schematic and wanted to know

why the HV pin1 is connected to rectified ac input via a resistor string.

Checking further the UCC256303 datasheet states the HV pin must be connected to GND.

Kind Regards,

Renan

over 4 years ago

0 Benjamin Lough over 4 years ago

TI__Mastermind 27105 points

Hi Renan,

The UCC25630-1EVM is populated with UCC256301 which uses these components to perform HV startup and X cap discharge. This EVM can be used to evaluate UCC256303 with minimal changes (see section 2.4 of the EVM user guide:https://www.ti.com/lit/ug/sluubq8b/sluubq8b.pdf?ts=1611705931862&ref_url=https%253A%252F%252Fwww.google.com%252F)

UCC256303 is a version of the UCC25630x LLC controller family that does not contain HV startup or X cap discharge. In this case, you would remove this circuitry altogether and connect HV pin directly to gnd.

I would also like to mention we have a newer version of the UCC256303 called UCC256403 which has some feature enhancementshttps://www.ti.com/product/UCC256403

Best Regards,

Ben Lough

Power management

Power management forum

UCC256303: EVM schematic inquiry