Part Number: UCC28951
Dear PL AE
my customer design in UCC28951 in their project and they have several issues as below associated with datasheet of UCC28951 need consult.
- in figure simplified appliaction(page 1), figure 7-18(page 35), 8-3(page 40), the ADEL pin connected to CS pin by RAHI. this meets all descriptive in the datasheet. but in figure 8-5(page 56), seems ADEL pin actually connected to VREF. is this correct and what is the reason?
- in page 46, what is part number for infineon's MOSFET? I checked IPP65R190CFD and several Infineon's 650V/20A CoolMOSFET. the output capacitance is in range 23~100pF and measured in 400V or 100V. the datasheet said the output capacitance is 780pF@25V. also, there has several output capacitance such as time related capacitance, energy related capacitance. so my question is: which cpacitance should be used to calculate tank frequency in Equation 89?
- Does TI has any document to explain equation 49 & 80?
- Does TI has any document to explain equation 90(page 52)? also, seems the equation 90 and equation 131(page 60) is not exactly same. which should I used to decide the delay time?
- in equation 134(page 61), what is voltage of CS? the KA=0.0405, according equation 134, I can deduce that voltage of CS=3.461V. this is over CS range: 0~2V. Do I have any mistake or misunderstanding?
- for equation 143(page 65), in my application, output voltage is vary from 0~500V. how should I calculate Me and then Rsum, RDCHMI?
big thanks for your supporting.
regards,
Bill
