Hi team,
Could you give me comment on following customer questions?
Q1. When implementing EMI filter (Pai type), could you check if following calculation is correct?
When CIN=40uF in Figure 9-21,
CD > 4 x 40uF (Due to CD > 4 x CIN)
=160uF. So CD > 160uF.
When choosing LIN = 3.3uH,
RD = sqrt (LIN/CIN)
= sqrt (3.3uH/40uF)
= 0.29Ohm, So RD > 0.29Ohm, the customer wants to select 0.33Ohm (since >0.29Ohm).
Q2. In the equation (43) at the datasheet for RCOMP, fc = 60kHz. Should the fc be changed depending on some design parameters , requirement, or is fc always 60kHz?
Q3. For Figure 9-21. RCOMP = 30.1kOhm. The customer assumes it is came by calculating fc = 60kHz, COUT = 130uF(effective Co1). But for Figure 9-21, it has dual-phase single output, so the customer thinks COUT should be used as 260uF (Co1 + Co2) in the calculation. Which COUT value is correct?
Q4. For CBST value, recommended value is 0.1uF. Based on the customer's calculation (by using eq (14)), CBSTmin = 0.26uF, and the customer will choose 0.33uF (or 0.47uF). Is it ok?
Best regards,
Takeshi Sasaki
