The LT1249 and LT1248 are both CCM PFC controllers. They are very similar chips.
Why is it that the LT1249 datasheet, on page 10, recommends a surge current bypass circuit (three diodes) for the sense resistor , but the LT1248 makes no mention of any need to protect from such surge currents? (eg the rush of current through the sense resistor if the PFC is switched on at Mains peak)
Also, The LT1248 leaves one with a choice of what maximum sense resistor voltage to employ…but what is the maximum?
LT1249 datasheet:
http://cds.linear.com/docs/en/datasheet/1249fbs.pdf
LT1248 datasheet
http://cds.linear.com/docs/en/datasheet/1248fd.pdf
Why is it that the LT1249 datasheet, on page 10, recommends a surge current bypass circuit (three diodes) for the sense resistor , but the LT1248 makes no mention of any need to protect from such surge currents? (eg the rush of current through the sense resistor if the PFC is switched on at Mains peak)
Also, The LT1248 leaves one with a choice of what maximum sense resistor voltage to employ…but what is the maximum?
LT1249 datasheet:
http://cds.linear.com/docs/en/datasheet/1249fbs.pdf
LT1248 datasheet
http://cds.linear.com/docs/en/datasheet/1248fd.pdf